BQ2084DBTR-V133 - Texas Instruments

bq2084-V133

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SLUS640B –JUNE 2005–REVISED FEBRUARY 2010

SBS v1.1-COMPLIANT GAS GAUGE FOR

USE WITH THE bq29312

Check for Samples: bq2084-V133

1FEATURES DESCRIPTION

• Provides Accurate Measurement of Available

Charge in Li-Ion and Li-Polymer Batteries The bq2084-V133 SBS-compliant gas gauge IC for

battery pack or in-system installation maintains an

• Supports the Smart Battery Specification accurate record of available charge in Li-ion or

(SBS) V1.1 Li-polymer batteries. The bq2084-V133 monitors

• Integrated Time Base Eliminates Need for capacity and other critical parameters of the battery

External Crystal pack and reports the information to the system host

– Optional Crystal input controller over a serial communication bus. It is

designed to work with the bq29312 AFE protection IC

• Works With the TI bq29312 Analog Front-End to maximize functionality and safety and minimize

(AFE) Protection IC to Provide Complete Pack component count and cost in smart battery circuits.

Electronics for 7.2-V, 10.8-V or 14.4-V Battery Using information from the bq2084-V133, the host

Packs With Few External Components controller can manage remaining battery power to

• Based on a Powerful Low-Power RISC CPU extend the system run time as much as possible.

Core With High-Performance Peripherals The bq2084-V133 uses an integrating converter with

• Integrated Flash Memory Eliminates the Need continuous sampling for the measurement of battery

for External Configuration EEPROM charge and discharge currents. Optimized for

coulomb counting in portable applications, the

• Uses 16-Bit Delta Sigma Converter for self-calibrating integrating converter has a resolution

Accurate Voltage and Temperature better than 0.65-nVh and an offset measurement

Measurements error of less than 1-µV (typical). For voltage and

• Measures Charge Flow Using a High temperature reporting, the bq2084-V133 uses a 16-bit

Resolution 16-Bit Integrating Converter A-to-D converter. With the bq29312, the onboard

– Better Than 0.65-nVh of Resolution ADC also monitors the pack and individual cell

voltages in a battery pack and allows the

– Self-Calibrating bq2084-V133 to generate the control signals

– Offset Error Less Than 1-µV necessary to implement the cell balancing and the

• Programmable Cell Modeling for Maximum required safety protection for Li-ion and Li-polymer

Battery Fuel Gauge Accuracy battery chemistries.

• Drives 3-, 4-, or 5-Segment LED Display for The bq2084-V133 supports the Smart Battery Data

Remaining Capacity Indication (SBData) commands and charge-control functions. It

communicates data using the System Management

• Available in a 38-Pin TSSOP (DBT) Package Bus (SMBus) 2-wire protocol. The data available

include the battery's remaining capacity, temperature,

APPLICATIONS voltage, current, and remaining run-time predictions.

• Notebook PCs The bq2084-V133 provides LED drivers and a

• Medical and Test Equipment pushbutton input to indicate remaining battery

• Portable Instrumentation capacity from full to empty in 20%, 25%, or 33%

increments with a 3-, 4-, or 5-segment display.

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas

Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

necessarily include testing of all parameters.

bq2084-V133

SLUS640B –JUNE 2005–REVISED FEBRUARY 2010

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These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam

during storage or handling to prevent electrostatic damage to the MOS gates.

DESCRIPTION (CONTINUED)

The bq2084-V133 contains 1k bytes of internal data flash memory, which store configuration information. The

information includes nominal capacity and voltage, self-discharge rate, rate compensation factors, and other

programmable cell-modeling factors used to accurately adjust remaining capacity for use-conditions based on

time, rate, and temperature. The bq2084-V133 also automatically calibrates or learns the true battery capacity in

the course of a discharge cycle from programmable near full to near empty levels.

The bq29312 analog front-end (AFE) protection IC is used to maximize functionality and safety and minimize

component count and cost in smart battery circuits. The bq29312 AFE protection IC provides power to the

bq2084-V133 from a 2-, 3-, or 4-series Li-ion cell stack, eliminating the need for an external regulator circuit.

ORDERING INFORMATION

PACKAGE

TA38-PIN TSSOP (DBT)

–20°C to 85°C bq2084DBT-V133(1)

(1) The bq2084-V133 is available taped and reeled. Add an R suffix to the device type (e.g.,

bq2084DBTR-V133) to order tape and reel version.

ABSOLUTE MAXIMUM RATINGS

over operating free-air temperature range unless otherwise noted(1)

UNIT

Supply voltage range, VDD relative to VSS (2) –0.3 V to 4.1 V

Open-drain I/O pins, V(IOD) relative to VSS (2) –0.3 V to 6 V

Input voltage range to all other pins, VIrelative to VSs (2) –0.3 V to VDD + 0.3 V

TAOperating free-air temperature range –20°C to 85°C

Tstg Storage temperature range –65°C to 150°C

(1) Stresses beyond those listed under absolute maximum ratings may cause permanent damage to the device. These are stress ratings

only, and functional operation of the device at these or any other conditions beyond those indicated under recommended operating

conditions is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.

(2) VSS refers to the common node of V(SSA), V(SSD), and V(SSP).

Product Folder Link(s): bq2084-V133

2.10

2.15

2.20

2.25

2.30

2.35

2.40

2.45

2.50

-20 -10 0 10 20 30 40 50 60 70 80 100

105

110

115

120

125

130

135

140

TA - Free-Air Temperature - °C

- Negative Going Input Threshold Voltage - V

POWER ON RESET BEHAVIOR

FREE-AIR TEMPERATURE

VIT

VIT-

Vhys

Vhys- Hysterisis Voltage - mV

bq2084-V133

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ELECTRICAL CHARACTERISTICS

VDD = 3.0 V to 3.6 V, TA= –20°C to 85°C unless otherwise noted

PARAMETER TEST CONDITIONS MIN TYP MAX UNIT

VDD Supply voltage VDDA and VDDD 3.0 3.3 3.6 V

No flash programming

IDD Operating mode current 380 µA

or LEDs active

I(SLP) Low-power storage mode current Sleep mode 8 µA

Output voltage low SMBC, SMBD, SDATA, SCLK, SAFE, PU IOL = 0.5 mA 0.4

VOL V

LED1-LED5 IOL = 10 mA 0.4

Input voltage low SMBC, SMBD, SDATA, SCLK, EVENT, –0.3 0.8

PU, PRES, PFIN

VIL V

DISP –0.3 0.8

Input voltage high SMBC, SMBD, SDATA, SCLK, EVENT, 2 6

PU, PRES, PFIN

VIH V

DISP 2 VDD + 0.3

V(AI1) Input voltage range VIN, TS VSS – 0.3 1.0 V

V(AI2) Input voltage range SR1, SR2 VSS – 0.25 0.25 V

Z(AI1) Input impedance SR1, SR2 –0.25 V to 0.25 V 2.5 MΩ

Z(AI2) Input impedance VIN, TS 0 V–1.0 V 8 MΩ

POWER-ON RESET

VIT+ Negative-going voltage input 2.1 2.3 2.5 V

Vhys Power-on reset hysteresis 50 125 200 mV

INTEGRATING ADC CHARACTERISTICS

VDD = 3.0 V to 3.6 V, TA= –20°C to 85°C unless otherwise noted

PARAMETER TEST CONDITIONS MIN TYP MAX UNIT

V(SR) Input voltage range, V(SR2) and V(SR1) VSR = V(SR2) – V(SR1) –0.25 0.25 V

V(SROS) Input offset 1 mV

INL Integral nonlinearity error FAST = 0, –0.1 V to 0.8 x Vref 0.004% 0.018%

PLL SWITCHING CHARACTERISTICS

VDD = 3.0 V to 3.6 V, TA= –20°C to 85°C unless otherwise noted

PARAMETER TEST CONDITIONS MIN TYP MAX UNIT

t(SP) Start-up time (1) ±0.5% frequency error 2 5 ms

(1) The frequency error is measured from the trimmed frequency of the internal system clock, which is 128 x oscillator frequency, nominally

4.194 MHz.

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OSCILLATOR

VDD = 3.0 V to 3.6 V, TA= –20°C to 85°C (unless otherwise noted) (TYP: VDD = 3.3 V, TA= 25°C)

PARAMETER TEST CONDITIONS MIN TYP MAX UNIT

ROSC = 100k –2% 0.5% 2%

f(eio) Frequency error from 32.768 kHz XCK1 = 12 pF XTAL –0.25% 0.25%

f(dio) Frequency drift(1) ROSC = 100k, TA= 0°C to 50°C –1% 1%

f(sio) ROSC = 100k 200 µs

Start-up time(2)

f(sxo) XCK1 = 12 pF XTAL 250 ms

(1) The frequency drift is measured from the trimmed frequency at VDD = 3.3 V, TA= 25°C.

(2) The start-up time is defined as the time it takes for the oscillator output frequency to be ±1%

DATA FLASH MEMORY CHARACTERISTICS

VDD = 3.0 V to 3.6 V, TA= –20°C to 85°C unless otherwise noted

PARAMETER TEST CONDITIONS MIN TYP MAX UNIT

tDR Data retention See (1) 10 Years

Flash programming write-cycles See (1) 20k Cycles

t(WORDPROG) Word programming time See (1) 2 ms

I(DDPROG) Flash-write supply current See (1) 8 12 mA

(1) Specified by design. Not production tested.

I(RBI) RBI data-retention input current VRBI > 2.0 V, VDD < VIT 10 100 nA

V(RBI) RBI data-retention voltage (1) 1.3 V

(1) Specified by design. Not production tested.

SMBus TIMING SPECIFICATIONS

VDD = 3.0 V to 3.6 V, TA= -20°C to 85°C unless otherwise noted

PARAMETER TEST CONDITIONS MIN TYP MAX UNIT

f(SMB) SMBus operating frequency Slave mode, SMBC 50% duty cycle 10 100 kHz

f(MAS) SMBus master clock frequency Master mode, no clock low slave extend 51.2 kHz

t(BUF) Bus free time between start and stop 4.7 µs

T(HD:STA) Hold time after (repeated) start 4.0 µs

t(SU:STA) Repeated start setup time 4.7 µs

t(SU:STO) Stop setup time 4.0 µs

Receive mode 0

t(HD:DAT) Data hold time ns

Transmit mode 300

tSU:DAT) Data setup time 250 ns

t(TIMEOUT) Error signal/detect See (1) 25 35 ms

t(LOW) Clock low period 4.7 µs

t(HIGH) Clock high period See (2) 4.0 50 µs

tLOW:SEXT) Cumulative clock low slave extend time See (3) 25 ms

tLOW:MEXT Cumulative clock low master extend time See (4) 10 ms

tfClock/data fall time (VILMAX – 0.15 V) to (VIHMIN + 0.15 V) 300 ns

trClock/data rise time 0.9 VDD to (VILMAX – 0.15 V) 1000 ns

(1) The bq2084-V133 times out when any clock low exceeds t(TIMEOUT).

(2) t(HIGH) Max. is minimum bus idle time. SMBC = 1 for t > 50 ms causes reset of any transaction involving bq2084-V133 that is in

progress.

(3) t(LOW:SEXT) is the cumulative time a slave device is allowed to extend the clock cycles in one message from initial start to the stop.

(4) t(LOW:MEXT) is the cumulative time a master device is allowed to extend the clock cycles in one message from initial start to the stop.

Product Folder Link(s): bq2084-V133

Power Management

LDO, TOUT and Power Mode Control

Pre-Charge Control Fail-Safe

Protection

Temperature Measurement

<1% Error TINT

1 k Bytes of

User Flash 32 kHz Clock

Generator

Cell Balancing Algorithm and Control

SBS v1.1 Data System Interface

bq29312 RAM/Comms Validation

1 st Level OC

Protection 1 st Level OV and

UV Protection

Pack Under

Voltage Power

Mode Control

Cell and Pack

Voltage

Measurement

Capacity Prediction <1% Error

Pres

SMBus

bq2084−V133

PCH FET Drive

Pre-Charge

FET Drive Cell Balancing

Drive

LDO, Therm Output Drive and UVLO

System

Watchdog Delay Counters

RAM RegistersSystem Interface

Power Mode Control

Voltage Level Translator

bq29312

2-Tier Overcurrent Protection

3.3 V

I2C

PF Input

Discharge / Charge /

Pre-Charge FETs

2nd Level Overvoltage Protection

Fuse

Pack +

Pack −

32 kHz

Sense Resistor

(5 to 30 mΩ)

bq2084-V133

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SMBus TIMING DIAGRAMS

SYSTEM DIAGRAM

Product Folder Link(s): bq2084-V133

VIN

VSSA

PRES

SCLK

VDDD

RBI

SDATA

VSSD

SAFE

SMBC

SMBD

DISP

PFIN

VSSD

CLKOUT

XCK1/VSSA

XCK2/ROSC

FILT

VDDA

VSSA

SR1

SR2

MRST

EVENT

LED1

LED2

LED3

LED4

LED5

TSSOP (DBT)

(TOP VIEW)

bq2084-V133

SLUS640B –JUNE 2005–REVISED FEBRUARY 2010

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PIN ASSIGNMENTS

Pin Functions

PINS I/O DESCRIPTION

NO.

NAME TSSOP

CLKOUT 35 O 32.768-kHz output to the bq29312

DISP 17 I Display control for the LED drivers LED1 through LED5

FILT 32 I Analog input connected to the external PLL filter

EVENT 25 I Input from bq29312 XALERT output

LED1 24 O

LED2 23 O

LED3 22 O LED display segments that each may drive an external LED

LED4 21 O

LED5 20 O

MRST 26 I Master reset input that forces the device into reset when held high

7, 13, 14,

NC – No connection

36, 37

PFIN 18 I Active low input to detect secondary protector output status

PRES 5 I Active low input to sense system insertion

PU 4 O Output to pull up the /PRES pin for detection

RBI 9 I Register backup that provides backup potential to the bq2084-V133 data registers during periods of low

operating voltage. RBI accepts a storage capacitor or a battery input.

SAFE 12 O Active low output for additional level of safety protection; e.g., fuse blow.

SCLK 6 O Communication clock to the bq29312

SDATA 10 I/O Data transfer to and from bq29312

SMBC 15 I/O SMBus clock open-drain bidirectional pin used to clock the data transfer to and from the bq2084-V133

SMBD 16 I/O SMBus data open-drain bidirectional pin used to transfer address and data to and from the

bq2084-V133

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Pin Functions (continued)

PINS I/O DESCRIPTION

NO.

NAME TSSOP

SR1 28 I Connections for a small-value sense resistor to monitor the battery charge- and discharge-current flow

SR2 27 I

TS 2 I Thermistor input to monitor temperature

VDDA 31 I Positive supply for analog circuitry

VDDD 8 I Positive supply for digital circuitry and I/O pins

VIN 1 I Single-cell voltage input from the bq29312

VSSA 3, 29, 30 I Negative supply for analog circuitry

VSSD 11, 19, 38 I Negative supply for digital circuitry

XCK1/VSSA 34 I 32.768-kHz crystal oscillator input pin or connected to VSSA if the internal oscillator is used

XCK2/ROSC 33 O 32.768-kHz crystal oscillator output pin or connected to a 100-kΩ, 50 ppm or better resistor if the

internal oscillator is used

FUNCTIONAL DESCRIPTION

OSCILLATOR FUNCTION

The bq2084-V133 can use an internal or an external oscillator. At powerup, the bq2084-V133 automatically

attempts to start the internal oscillator. If a 100-kΩresistor is not connected to ROSC (pin 33), then it attempts to

start the oscillator using an external 32.768-kHz crystal. Install either the 100-kΩROSC resistor or the 12 pF

32.768-kHz crystal, not both.

The performance of the internal oscillator depends on the tolerance of the 100-kΩresistor connected between

RSOC (pin 33) and VSSA (pin 34). It is recommended that this resistor be as close to the bq2084-V133 as

possible and that it has a specification of ±0.1% tolerance and ±50 ppm temperature drift or better. The 12-pF

crystal, if used, should also be placed as close to the XCK1 (pin 34) and XCK2 (pin 33) pins as possible. The

PCB layout around these pins and components can degrade oscillator performance if not carefully implemented.

The average oscillator temperature-drift error during a learning charge or a discharge cycle introduces an equal

capacity-prediction error in the learned full-charge capacity value (FCC).

SYSTEM PRESENT OPERATION

When the bq2084-V133 detects that the battery is inserted into the system via a low state on the PRES input, the

bq2084-V133 enters normal operating mode and sets the PRES bit in PackStatus(). The discharge FET turns on

within 250 ms of pack insertion. When the pack is removed from the system and the PRES input is high, then the

bq2084-V133 enters the battery removed state and turns OFF the charge and discharge FETs, and enables the

0-V/precharging FET. If NR in Misc Config is set, then the PRES input can be left floating as it is not used.

GENERAL OPERATION

The bq2084-V133 determines battery capacity by monitoring the amount of charge input or removed from a

rechargeable battery. In addition to measuring charge and discharge, the bq2084-V133 measures individual cell

voltages, pack voltage, temperature, and current, estimates battery self-discharge, and monitors the battery for

low-voltage thresholds using features of the bq29312 AFE device.

The bq2084-V133 measures charge and discharge activity by monitoring the voltage across a small-value series

sense resistor between the cell stack negative terminal and the negative terminal of the battery pack. The

available battery charge is determined by monitoring this voltage and correcting the measurement for

environmental and operating conditions.

The bq2084-V133 interfaces with the bq29312 to perform battery protection, cell balancing, and voltage

translation functions. The bq2084-V133 can accept any NTC thermistor (default is Semitec 103AT) for

temperature measurement or can also be configured to use its internal temperature sensor. The bq2084-V133

uses temperature to monitor the battery pack and to compensate the self-discharge estimate.

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MEASUREMENTS

The bq2084-V133 uses an integrating sigma-delta analog-to-digital converter (ADC) for current measurement

and a second sigma-delta ADC for individual cell and battery voltage and temperature measurement. The

individual cell and pack voltages, Voltage(),Current(),AverageCurrent() and Temperature() are updated every 1

s during normal operation.

CHARGE AND DISCHARGE COUNTING

The integrating ADC measures the charge and discharge flow of the battery by monitoring a small-value sense

resistor between the SR1 and SR2 pins. The integrating ADC measures bipolar signals from -0.25 V to 0.25 V.

The bq2084-V133 detects charge activity when VSR = V(SR1)-V(SR2) is positive and discharge activity when VSR

= V(SR1)-V(SR2) is negative. The bq2084-V133 continuously integrates the signal over time, using an internal

counter. The fundamental rate of the counter is 0.65 nVh. The bq2084-V133 updates RemainingCapacity() with

the charge or discharge accumulated in this internal counter once every second.

OFFSET CALIBRATION

The bq2084-V133 provides an auto-calibration feature to cancel the voltage offset error across SR1 and SR2 for

maximum charge measurement accuracy. The bq2084-V133 performs auto-calibration when the SMBus lines

stay low for a minimum of 20 s when it internally connects SR1 to SR2 and measures the internal offset. With

this feature the bq2084-V133 is capable of automatic offset calibration down to <1 µV.

DIGITAL FILTER

The bq2084-V133 does not measure charge or discharge counts below the digital filter threshold. The digital filter

threshold is programmed in the Digital Filter (DF 0x2c) and should be set sufficiently high to prevent false signal

detection with no charge or discharge flowing through the sense resistor.

VOLTAGE

While monitoring SR1 and SR2 for charge and discharge currents, the bq2084-V133 monitors the individual

series cell voltages through the bq29312. The bq2084-V133 configures the bq29312 to present the selected cell

to the CELL pin of the bq29312, which should be connected to VIN of the bq2084-V133. The internal ADC of the

bq2084-V133 then measures the voltage and scales it appropriately. The bq2084-V133 then reports the

Voltage() and the individual cell voltages in VCELL1(),VCELL2(),VCELL3(), and VCELL4(). An additional

SMBus command (0x45) returns the measured ADC Reading of the PACK input to the AFE.

CURRENT

The bq2084-V133 uses the SR1 and SR2 inputs to measure and calculate the battery charge and discharge

current. This value is reported via the SBS command Current().AverageCurrent() is implemented as a

single-pole IIR filter with a 14.5-s time constant.

TEMPERATURE

The TS input of the bq2084-V133 along with an NTC thermistor measures the battery temperature as shown in

the schematic. The bq2084-V133 reports temperature via the SBS command Temperature().

The bq2084-V133 can also be configured to use its internal temperature sensor by setting the IT bit in Misc

Configuration (DF 0x2a-0x2b). Data flash locations DF 0xb5 through DF 0xc0 also have to be changed to

prescribed values if the internal temperature sensor option is selected.

Table 1. Data Flash Settings for Internal or External Temperature Sensor

INTERNAL TEMP EXTERNAL TEMP SENSOR SETTING

LOCATION SENSOR SETTING (Semitec 103AT)

LABEL Dec (Hex) Dec (Hex) Dec (Hex)

Misc. Config 42 (0x2a) Bit 7 = 1 Bit 7 = 0

TS Const1 A3 164/5 (0xb5/6) 0 (0x0000) –28285 (0x9183)

TS Const2 A2 166/7 (0xb7/8) 0 (0x0000) 20848 (0x5170)

TS Const3 A1 168/9 (0xb9/a) –11136 (0xd480) –7537 (0xe28f)

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Table 1. Data Flash Settings for Internal or External Temperature Sensor (continued)

INTERNAL TEMP EXTERNAL TEMP SENSOR SETTING

LOCATION SENSOR SETTING (Semitec 103AT)

LABEL Dec (Hex) Dec (Hex) Dec (Hex)

TS Const4 A0 170/1 (0xbb/c) 5734 (0x1666) 4012 (0x0fac)

Min Temp AD 172/3 (0xbd/e) 0 (0x0000) 0 (0x000)

Max Temp 174/5 (0xbf/c0) 5734 (0x1666) 4012 (0x0fac)

GAS GAUGE OPERATION

General

The operational overview in Figure 1 illustrates the gas gauge operation of the bq2084-V133. Table 3 describes

the bq2084-V133 registers.

Figure 1. bq2084-V133 Gas Gauging Operational Overview

The bq2084-V133 accumulates a measure of charge and discharge currents and estimates self-discharge of the

battery. The bq2084-V133 compensates the charge current measurement for temperature and state-of-charge of

the battery. The bq2084-V133 also adjusts the self-discharge estimation based on temperature.

The main charge counter RemainingCapacity() (RM) represents the available capacity or energy in the battery at

any given time. The bq2084-V133 adjusts RM for charge, self-discharge, and other compensation factors. The

information in the RM register is accessible through the SMBus interface and is also represented through the

LED display.

The FullChargeCapacity() (FCC) register represents the last measured learned full discharge of the battery. It is

used as the battery full-charge reference for relative capacity indication. The bq2084-V133 updates FCC after the

battery undergoes a qualified discharge from nearly full to a low battery level. FCC is accessible through the

SMBus interface.

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The Discharge Count Register (DCR) is a non-accessible register that tracks discharge of the battery. The

bq2084-V133 uses the DCR register to update the FCC register if the battery undergoes a qualified discharge

from nearly full to a low battery level. In this way, the bq2084-V133 learns the true discharge capacity of the

battery under system-use conditions.

Main Gas-Gauge Registers

RemainingCapacity() (RM)

RM represents the remaining capacity in the battery. The bq2084-V133 computes RM in units of either mAh or

10 mWh depending on the selected mode. See Battery Mode() (0x03) for units configuration. RM counts up

during charge to a maximum value of FullChargeCapacity() (FCC) and down during discharge and self-discharge

to a minimum of 0. In addition to charge and self-discharge compensation, the bq2084-V133 calibrates RM at

three low-battery-voltage thresholds, EDV2, EDV1, and EDV0 and three programmable midrange thresholds

VOC25, VOC50, and VOC75. This provides a voltage-based calibration to the RM counter.

DesignCapacity () (DC)

DC is the user-specified battery full capacity. It is calculated from Pack Capacity (DF 0x32-0x33) and is

represented in units of mAh or 10 mWh. It also represents the full-battery reference for the absolute display

mode.

FullChargeCapacity() (FCC)

FCC is the last learned measured discharge capacity of the battery. It is represented in units of either mAh or 10

mWh, depending on the selected mode. On initialization, the bq2084-V133 sets FCC to the value stored in Full

Charge Capacity (DF 0x36-0x37). During subsequent discharges, the bq2084-V133 updates FCC with the last

learned measured discharge capacity of the battery. The last learned measured discharge of the battery is based

on the value in the Discharge Count Register (DCR) after a qualified discharge occurs. Once updated, the

bq2084-V133 writes the new FCC value to data flash in mAh to Full Charge Capacity. FCC represents the

full-battery reference for the relative display mode, relative state of charge and AtRate() calculations.

Discharge Count Register (DCR)

The DCR register counts up during discharge, independent of RM. DCR counts discharge activity, battery load

estimation, and self-discharge increments. The bq2084-V133 initializes DCR, at the beginning of a discharge, to

FCC - RM when FCC - RM is within the programmed value in Near Full DF 0x30. The DCR initial value of FCC -

RM is reduced by FCC/128 if SC = 1 (bit 5 in Gauge Configuration) and is not reduced if SC = 0. DCR stops

counting when the battery voltage reaches the EDV2 threshold on discharge.

Capacity Learning (FCC Update) and Qualified Discharge

The bq2084-V133 updates FCC with an amount based on the value in DCR if a qualified discharge occurs. The

new value for FCC equals the DCR value plus the programmable nearly full and low battery levels, according to

the following equation:

FCC (new) = DCR (final) = DCR (initial) + Measured Discharge to EDV2 + (FCC x Battery Low%)

here Battery Low % = (value stored in DF 0x2f) ÷ 2.56

A qualified discharge occurs if the battery discharges from RM = FCC - Near Full to the EDV2 voltage threshold

with the following conditions:

• No more than 256 mAh of self-discharge or battery load estimation occurs during the discharge period.

• The temperature does not drop below the low temperature threshold programmed in Learning Low Temp DF

0xac during the discharge period.

• The battery voltage reaches the EDV2 threshold during the discharge period, and the voltage is ≥EDV2

threshold – 256 mV when the bq2084-V133 detects EDV2.

• No midrange voltage correction occurs during the discharge period.

• Current remains ≥3C/32 when EDV2 or Battery Low % level is reached.

• No overload condition exists when EDV2 threshold is reached, or if RM() has dropped to Battery Low% x

FCC,

• No valid charge activity occurs during the discharge period. A valid charge is defined as an uninterrupted

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charge of 10 mAh into the battery.

The bq2084-V133 sets VDQ = 1 in PackStatus() when qualified discharge begins. The bq2084-V133 sets VDQ =

0 if any disqualifying condition occurs. FCC cannot be reduced by more than 256 mAh or increased by more than

512 mAh during any single update cycle. The bq2084-V133 saves the new FCC value to the data flash within 4

seconds of being updated.

End-of-Discharge Thresholds and Capacity Correction

The bq2084-V133 monitors the battery for three low-voltage thresholds, EDV0, EDV1, and EDV2. The EDV

thresholds can be programmed for determination based on the overall pack voltage or an individual cell level.

The EDVV bit in Pack Configuration DF 0x28 configures the bq2084-V133 for overall voltage or single-cell EDV

thresholds. If programmed for single-cell EDV determination, the bq2084-V133 determines EDV on the basis of

the lowest single-cell voltage. Fixed EDV thresholds must be programmed in EMF/EDV0 DF 0x95-0x96, EDV C0

Factor/EDV1 DF 0x97-0x98, and EDV R Factor/EDV2 DF 0x99-0x9a.

If the CEDV bit in Gauge Configuration DF 0x29 is set, automatic compensated EDVs are enabled and the

bq2084-V133 computes the EDV0, EDV1, and EDV2 voltage thresholds based on the values in DF 0x95-0xa0

and the battery's current discharge rate and temperature. The bq2084-V133 disables EDV detection if Current( )

exceeds the Overload Current threshold programmed in DF 0x5b-DF 0x5c. The bq2084-V133 resumes EDV

threshold detection after Current() drops below the Overload Current threshold. Any EDV threshold detected is

reset after charge is detected and VDQ is cleared after 10 mAh of charge.

The bq2084-V133 uses the EDV thresholds to apply voltage-based corrections to the RM register according to

Table 2.

Table 2. State-of-Charge Based on Low Battery Voltage

THRESHOLD RELATIVE STATE OF CHARGE

EDV0 0%

EDV1 3%

EDV2 Battery Low %

The bq2084-V133 performs EDV-based RM adjustments with Current() ≥C/32. No EDV flags are set if current <

C/32.

The bq2084-V133 adjusts RM as it detects each threshold. If the voltage threshold is reached before the

corresponding capacity on discharge, the bq2084-V133 reduces RM to the appropriate amount as shown in

Table 2.

If an RM % level is reached on discharge before the voltage reaches the corresponding threshold, then RM is

held at that % level until the threshold is reached. RM is only held if VDQ = 1, indicating a valid learning cycle is

in progress. If Battery Low % is set to zero, EDV1 and EDV0 corrections are disabled.

EDV Thresholds and Near-Full Programming

The bq2084-V133 uses the values stored in data flash for the EDV0, EDV1, and EDV2 values or calculates the

three thresholds from a base value and the temperature, capacity, and rate adjustment factors stored in data

flash. If EDV compensation is disabled, then EDV0, EDV1, and EDV2 are stored directly in mV in DF 0x95-0x96,

DF 0x97-0x98, and DF 0x99-0x9a, respectively.

For capacity correction at EDV2, Battery Low % DF 0x2f can be set at a desired state-of-charge,

STATEOFCHARGE%, in the range of 3-19%. Typical values for STATEOFCHARGE% are 5-7%, representing

5-7% capacity.

Battery Low % = (STATEOFCHARGE% x 2.56)

The bq2084-V133 updates FCC if a qualified discharge occurs from a near-full threshold of FCC - Near Full, until

EDV2 condition is reached. The desired near-full threshold window is programmed in Near Full (DF 0x30, 0x31)

in mAh.

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EDV Discharge Rate and Temperature Compensation Programming

If EDV compensation is enabled, the bq2084-V133 calculates battery voltage to determine EDV0, EDV1, and

EDV2 thresholds as a function of battery capacity, temperature, and discharge load. The general equation for

EDV0, EDV1, and EDV2 calculation is

EDV0,1,2 = n (EMF × FBL – | ILOAD | × R0 × FTZ)

EMF is a no-load cell voltage higher than the highest cell EDV threshold computed. EMF is programmed

in mV in EMF/EDV1 (DF 0x95-0x96).

ILOAD is the current discharge load magnitude.

n = the number of series cells

FBL is the factor that adjusts the EDV voltage for battery capacity and temperature to match the no-load

characteristics of the battery.

FBL=f(C0,C+C1,T)

C (either 0%, 3%, or Battery Low % for EDV0, EDV1, and EDV2, respectively) and C0 are the

capacity-related EDV adjustment factors. C0 is programmed in EDV C0 Factor/EDV1 (DF 0x97-98). C1

is the desired residual battery capacity remaining at EDV0 (RM = 0). The C1 factor is stored in EDV C1

Factor (DF 0xa0).

T is the current temperature in °K.

R0 × FTZ represents the resistance of a cell as a function of temperature and capacity.

FTZ = f ( R1, T0, T, C + C1, TC)

R0 is the first order rate dependency factor stored in EDV R0 Factor/EDV2 DF 0x99-0x9a.

T is the current temperature; C is the battery capacity relating to EDV0, EDV1, and EDV2.

R1 adjusts the variation of impedance with battery capacity. R1 is programmed in EDV R1 Rate Factor

(DF 0x9d-0x9e).

T0 adjusts the variation of impedance with battery temperature. T0 is programmed in EDV T0 Rate

Factor (DF 0x9b-0x9c).

TC adjusts the variation of impedance for cold temperatures (T < 23°C). TC is programmed in EDV TC

(DF 0x9f).

Typical values for the EDV compensation factors, based on overall pack voltages for a Li-ion 3s2p 18650 pack,

are:

EMF = 11550/3

T0 = 4475

C0 = 235

C1 = 0

R0 = 5350/3

R1 = 250

TC = 3

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Table 3. bq2084-V133 Register Functions

FUNCTION COMMAND CODE ACCESS UNITS

ManufacturerAccess 0x00 Read/write NA

RemainingCapacityAlarm 0x01 Read/write mAh, 10 mWh

RemainingTimeAlarm 0x02 Read/write minutes

BatteryMode 0x03 Read/write NA

AtRate 0x04 Read/write mA, 10 mW

AtRateTimeToFull 0x05 Read minutes

AtRateTimeToEmpty 0x06 Read minutes

AtRateOK 0x07 Read Boolean

Temperature 0x08 Read 0.1°K

Voltage 0x09 Read mV

Current 0x0a Read mA

AverageCurrent 0x0b Read mA

MaxError 0x0c Read percent

RelativeStateOfCharge 0x0d Read percent

AbsoluteStateOfCharge 0x0e Read percent

RemainingCapacity 0x0f Read mAh, 10 mWh

FullChargeCapacity 0x10 Read mAh, 10 mWh

RunTimeToEmpty 0x11 Read minutes

AverageTimeToEmpty 0x12 Read minutes

AverageTimeToFull 0x13 Read minutes

ChargingCurrent 0x14 Read mA

ChargingVoltage 0x15 Read mV

Battery Status 0x16 Read NA

CycleCount 0x17 Read cycles

DesignCapacity 0x18 Read mAh, 10 mWh

DesignVoltage 0x19 Read mV

SpecificationInfo 0x1a Read NA

ManufactureDate 0x1b Read NA

SerialNumber 0x1c Read integer

Reserved 0x1d-0x1f 0 0

ManufacturerName 0x20 Read string

DeviceName 0x21 Read string

DeviceChemistry 0x22 Read string

ManufacturerData 0x23 Read string

Pack status 0x2f (LSB) Read NA

Pack configuration 0x2f (MSB) Read NA

VCELL4 0x3c Read mV

VCELL3 0x3d Read mV

VCELL2 0x3e Read mV

VCELL1 0x3f Read mV

VPACK 0x45 Read mV

AFEData 0x46 Read hex

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Self-Discharge

The bq2084-V133 estimates the self-discharge of the battery to maintain an accurate measure of the battery

capacity during periods of inactivity. The bq2084-V133 makes self-discharge adjustments to RM every 1/4 s

when awake and periodically (determined by Sleep Timer DF 0xfe) when in sleep mode. The self-discharge

estimation rate for 25°C is doubled for each 10 degrees above 25°C or halved for each 10 degrees below 25°C.

Table 4 shows the relation of the self-discharge estimation at a given temperature to the rate programmed for

25°C (Y% per day programmed in DF 0x2d).

Table 4. Self-Discharge for Rate Programmed

TEMPERATURE (°C) SELF-DISCHARGE RATE

Temp < 10 1/4 Y% per day

10 ≤Temp <20 1/2 Y% per day

20 ≤Temp <30 Y% per day

30 ≤Temp <40 2Y% per day

40 ≤Temp <50 4Y% per day

50 ≤Temp <60 8Y% per day

60 ≤Temp <70 16Y% per day

70 ≤Temp 32Y% per day

The nominal self-discharge rate, %PERDAY (% per day), is programmed in an 8-bit value Self-Discharge Rate

(DF 0x2d) by the following relation:

Self-Discharge Rate = %PERDAY ÷ 0.01

Battery Electronic Load Compensation

The bq2084-V133 can be configured to compensate for a constant load (as from battery electronics) present in

the battery pack at all times. The bq2084-V133 applies the compensation continuously when the charge or

discharge is below the digital filter. The bq2084-V133 applies the compensation (BEL) in addition to

self-discharge. The compensation occurs at a rate determined by the value stored in Electronics Load (DF 0x2e).

The compensation range is 0 µA-765 µA in steps of approximately 3 µA.The data is stored as follows:

Electronics Load = BEL ÷ 3

Midrange Capacity Corrections

The bq2084-V133 applies midrange capacity corrections when the VCOR bit is set in Gauge Configuration DF

0x29. The bq2084-V133 adjusts RM to the associated percentage at three different voltage levels: VOC25,

VOC50, and VOC75. The VOC values represent the open-circuit battery voltage at which RM corresponds to the

associated percentage for each threshold.

For the midrange corrections to occur, the temperature must be in the range of 19°C to 31°C inclusive and

Current() and AverageCurrent() must both report between -64 mA and 0. The bq2084-V133 makes midrange

corrections as shown in Table 5. For a correction to occur, the bq2084-V133 must detect the need for correction

twice during subsequent 20-s intervals. With the VCOR bit set, the bq2084-V133 makes midrange corrections

whenever conditions permit.

If the OTVC bit in Gauge Configuration (DF 0x29) is set and VCOR = 0, the bq2084-V133 makes two Voltage()

measurements, determines the average of the two readings and sets the appropriate RM level. No further

RSOC% vs Voltage() validation is performed until after the next device reset.

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Table 5. Midrange Corrections

CONDITION RESULT

≥VOC75 and RelativeStateOfCharge() ≤63% RelativeStateOfCharge() →75%

< VOC75 and RelativeStateOfCharge() ≥87% RelativeStateOfCharge() →75%

≥VOC50 and RelativeStateOfCharge() <38% RelativeStateOfCharge() →50%

Voltage() <VOC50 and RelativeStateOfCharge() ≥62% RelativeStateOfCharge() →50%

≥VOC25 and RelativeStateOfCharge() ≤13% RelativeStateOfCharge() →25%

< VOC25 and RelativeStateOfCharge() ≥37% RelativeStateOfCharge() →25%

Three voltage-based thresholds, VOC25 (DF 0x88-0x89), VOC50 (DF 0x83-0x84), and VOC75 (DF 0x7e-0x7f),

are stored in the data flash in mV.

Charge Control

The bq2084-V133 internal charge control is compatible with the constant current/constant voltage profile for

Li-ion. The bq2084-V133 detects primary charge termination on the basis of the tapering charge current during

the constant-voltage phase.

Charging Voltage Broadcasts

The bq2084-V133 supports SBS charge control by broadcasting the ChargingCurrent() and ChargingVoltage() to

the Smart Charger address. The bq2084-V133 broadcasts the requests every 10 seconds. The bq2084-V133

updates the values used in the charging current and voltage broadcasts based on the battery's state of charge,

voltage, and temperature.

The 16-bit value (mV) for charging voltage is programmed in Charging Voltage (DF 0x03a-0x3b) although it can

be set to 0 in different operating conditions. It also sets the base value for determining overvoltage conditions

during charging and voltage compliance during a constant-voltage charging methodology.

The 16-bit value, Over Voltage Margin (DF 0x5d-0x5e), sets the limit over ChargingVoltage() in mV that is to be

considered as an overvoltage charge-suspension condition.

Charging Current Broadcasts

ChargingCurrent() values are either broadcast to a Level 2 smart battery charger or read from the bq2084-V133

by a Level 3 smart battery charger. The ChargingCurrent() may take any of four different values: Fast-Charging

Current DF (0x3e-0x3f), Maintenance Charging Current (DF 0x40-0x41), Precharge Current (DF 0x42-0x43) or 0

depending on charge state and operating conditions.

When fast charge is allowed, the bq2084-V133 sets ChargingCurrent() to the rate programmed in Fast-Charging

Current DF 0x3e-0x3f. Fast-Charging Current is stored in mA.

When fast charge terminates, the bq2084-V133 sets ChargingCurrent() to zero and then to the

MaintenanceCharging Current (DF 0x40-0x41) when the termination condition ceases. The desired maintenance

current is stored in mA.

When Voltage() is less than EDV0, the bq2084-V133 sets ChargingCurrent() to Precharge Current (DF

0x42-0x43). Typically this rate is larger than the maintenance rate to charge a deeply depleted pack up to the

point where it may be fast charged. The desired precharge rate is stored in mA.

If temperature is between the Charge Inhibit Temp Low (DF0x46) and the precharge threshold PC (°C), the

bq2084-V133 sets ChargingCurrent() to Precharge Current. The threshold is programmed in the Precharge

Temp (DF 0x44). The maximal value of precharge temperature threshold setting is 12.7°C.

•Precharge Temp = PC (°C) / 0.1

The bq2084-V133 also sets ChargingCurrent() to the precharge rate if Voltage() is less than the value

programmed in Precharge Voltage (DF 0x3c-0x3d). Precharge Voltage is programmed in mV.

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Alarm Broadcasts to Smart Charger and Host

If any of the bits 8-15 in BatteryStatus() are set, the bq2084-V133 broadcasts an AlarmWarning() message to the

Host address. If any of the bits 12-15 in BatteryStatus() are set, the bq2084-V133 also sends an AlarmWarning()

message to the Smart Charger address. The bq2084-V133 repeats the AlarmWarning() messages every 10

seconds until the alarm bits are cleared. All broadcasts can be disabled by setting SM (bit 2) in Pack

Configuration (DF 0x28).

Precharge Qualification

The bq2084-V133 sets ChargingCurrent() to the precharge rate as programmed in Precharge Current (DF

0x42-0x43) under the following conditions:

• Voltage: The bq2084-V133 requests the precharge charge rate when any cell voltage drops below the

precharge threshold or when the EDV0 threshold is detected. Once requested, a precharge rate remains until

all cell voltages increase above the precharge threshold and the EDV0 condition does not exist. The

precharge threshold is programmed in Precharge Voltage (DF 0x3c-0x3d).

• Temperature: The bq2084-V133 requests the precharge rate when Temperature() is between Charge Inhibit

Temp Low (DF 0x46) and the precharge threshold programmed in Precharge Temp (DF 0x44). Temperature()

must be equal to or greater than the precharge threshold + 3°C to allow the fast-charge rate.

Charge Suspension

The bq2084-V133 may temporarily suspend charge if it detects a charging fault. A charging fault includes the

following conditions.

• Overcurrent: An overcurrent condition exists when the bq2084-V133 measures the charge current to be

greater than Charge OC Threshold (DF 0x12a-0x12b) for a time greater than Charge OC Time (DF 0x12c).

On detecting an overcurrent condition, the bq2084-V133 turns off the Charge FET. If the Nonremovable

Battery bit is not set in Misc Configuration (DF 0x2a), then the Discharge FET is turned off also. This

condition is cleared when the pack is removed or if the Nonremovable Battery bit is set in Misc Configuration

(DF 0x2a) and when a discharge current is detected or when SBS AverageCurrent() is less than the

ClearFailCurrent (DF 0x61-0x62) for FaultResetTime (DF 0x130).

• Overtemperature: During charging, an overtemperature condition exists when Temperature() is greater than

the Charge Suspend Temp High value programmed in DF 0x6d, 0x6e. On detecting an overtemperature

condition, if enabled by the OT bit in Misc Configuration (DF 0x2a), the bq2084-V133 turns off the Charge

and Discharge FETs. The overtemperature condition is cleared when Temperature() is equal to or below

Charge Suspend Temp High Reset (DF 0x6f-0x70). The condition is also cleared if the pack is removed.

• Undertemperature: During charging, an undertemperature condition exists when Temperature() is less than

the Charge Suspend Temp Low (DF 0x79) or Charge Inhibit Temp Low (DF 0x46). On detecting an

undertemperature condition the bq2084-V133 turns off the Charge FET. The undertemperature condition is

cleared when Temperature() is greater than Charge Suspend Temp Low DF 0x79.The condition is also

cleared if the pack is removed. The maximal value of Charge Suspend Temp Low setting is 12.7°C.

• Charging exceeds Maximum Charging Time (DF 0x10f-0x110). If charging time reaches Maximum Charge

Time, the Charge FET is turned off. This condition is cleared when the pack detects discharge current or is

removed.

• Cell or Pack Overvoltage: An overvoltage condition exist when any cell is greater than Cell Over Voltage Limit

(DF 0x63-0x64) or if Voltage() is greater than Charging Voltage (DF 0x3a-0x3b) plus OvervoltageMargin (DF

0x5d-05e). This condition is cleared when the pack is removed or if the Nonremovable Battery bit is set in

Misc Configuration (DF 0x2a) and when a discharge current is detected or when SBS AverageCurrent() is

less than the ClearFailCurrent (DF 0x61-0x62) for FaultResetTime (DF 0x130). Also, the overvoltage conditon

must be cleared by Voltage() less than Charging Voltage (DF 0x3a-0x3b) plus OvervoltageMargin (DF

0x5d-05e) and all cell voltages less than Cell Over Voltage Reset (DF 0xe0-0xe1).

• Charging is also temporarily suspended during pulse-charging, but this is not considered a fault condition.

Pulse Charge

The bq2084-V133 is capable of charge control using a pulse-charging algorithm, which allows for charge control

in systems where the charger does not control current.

The pulse-charging algorithm uses voltage thresholds and associated time limits for control. These are stored as

constants in data flash. The cell voltages are read by the a/d converter every 125 ms during charging. The

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voltage used for comparison to the thresholds is the highest cell voltage. These thesholds are set by three data

flash constants: Von Charge Voltage,Voff Charge Voltage, and Vmax Charge Voltage.Von is the lowest of

these, and is the threshold below which the charge FET is turned on, provided the minimum off time (Pulse

Minimum Off Time) has been met. When the voltage crosses the Voff theshold, the maximum on time (Pulse

Maximum On Time) begins to count down. When this time has expired, the charge FET is turned off. Any time

Vmax is exceeded, the charge FET is turned off immediately.

The rules are:

1. If charge FET is on:

(a) If voltage above Vmax, turn off.

(b) Else if voltage above Voff and max on time expired, turn off.

2. If charge FET is off:

(a) If voltage below Von and minimum off time, turn on.

(b) Else increment off time.

Voltage is sampled every 125 ms; therefore, the minimum off time and maximum on time are in units of 125 ms,

and pulse on and off times are integral multiples of 125 ms.

The voltage thresholds can be chosen in such a way that they alter the charge mechanism. If Voff is set equal to

Vmax, then every time this theshold is crossed, the charge FET turns off immediately. This effectively disables

the maximum charge time, so that the Voff theshold has no effect. In this case, the algorithm can be described

as having two voltage thresholds, rather than three. The charge FET simply turns on and off as it crosses the two

thresholds.

The minimum off time can be similarly disabled by setting it to zero or one. Due to the sample interval, the

charge FET always is off for at least one 125-ms cycle.

Thesholds must be chosen carefully to get the desired charging behavior. For example, if Von is set below

charge voltage minus taper voltage, the pack can never detect full charge. During pulse charging, the charge

FET remains off until the cells relax to below the Von voltage, which is below the qualification voltage for full

charge detection.

During cycle phase of pulse charging (charge FET ON), the voltage can exceed Voff value for a period of 125 ms

until next sample is taken and FET is switched OFF. To prevent cell overvoltage termination, or pack overvoltage

termination during this period, values for cell OV should be set larger than voltage reached during this period.

Reasonable value of cell OV for given charger current I can be calculated, assuming cell impedance of 0.08

Ω/cell, as V(cell)OV > Von + 0.08 × I.

Correspondingly, the pack overvoltage margin should be set as V(margin) > V(cell)OVxn-V(charge)

where: n = number of series cells.

When charging begins on a depleted battery pack, the voltage is below Voff, and may even stay below Von for

some time. This means the pack is under constant charge, with no pulsing, for some part of the charge cycle. As

the voltage on the cells rises, it crosses the Voff theshold (or the Vmax threshold if Voff is disabled), and the

charge FET turns off. Initially, the off time is short, because the cells are only barely over the threshold and is

quickly relaxed to below Von. As the cell voltages rises, the off times become longer and the on times shorter.

This effect, in combination with the reduced current drawn by the cells, results in a gradually declining charge

current. Eventually, this current falls below the taper current, and the pack detects the full charge condition and

stops charging.

The pulse-charging control operates during normal charging conditions and are overridden in case of a fault

condition. Charging is stopped for any fault conditions which may occur, such as overtemperature or overcurrent,

without regard to the voltage thresholds or time limits.

Primary Charge Termination

The bq2084-V133 terminates charge if it detects a charge-termination condition based on current taper. A

charge-termination condition includes the following:

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The bq2084-V133 detects a current taper termination when the pack voltage is greater than Charging

Voltage (DF 0x3a-0x3b) minus Current Taper Qualification Voltage (DF 0x4d-0x4e) and the

AverageCurrent() is below the Current Taper Threshold (DF 0x4b-0x4c), but greater than the Charge

Detection Current (DF 0x113-0x114), for a period of Current Taper Window (DF 0x4f).

Once the bq2084-V133 detects a Primary Charge Termination, the bq2084-V133 sets the

TERMINATE_CHARGE_ ALARM and FULLY_CHARGED bits in BatteryStatus(), and turns off the charge

FET via the bq29312. The charge FET is turned on when discharge current is detected and is greater than

Discharge Detection Current (DF 0x115-0x116), to minimize IR losses. The TERMINATE_CHARGE_

ALARM charge current is no longer detected or the pack is removed, but returns if charging is attempted

while the FULLY_CHARGED bit is set.

The bq2084-V133 clears the FULLY_CHARGED and TERMINATE_CHARGE_ALARM bit when

RelativeStateOfCharge() is less than the programmed Fully Charged Clear %. See Table 13 for a summary

of BatteryStatus() alarm and status bit operation.

Cell Balancing

The bq2084-V133 balances the cells during charge by discharging those cells above the threshold set in Cell

Balance Threshold (DF 0xe8-0xe9), if the maximum difference in cell voltages exceeds the value programmed in

Cell Balance Min (DF 0xec). For cell balancing, the bq2084-V133 measures the cell voltages at an interval set in

Cell Balance Interval (DF 0xed). On the basis of the cell voltages, the bq2084-V133 either selects the appropriate

cell to discharge or adjusts the cell balance threshold up by the value programmed in Cell Balance Window (DF

0xea-0xeb) when all cells exceed the cell balance threshold or the highest cell exceeds the cell balance

threshold by the cell balance window.

Cell balancing only occurs when charging current is detected and the cell balance threshold is reset to the value

in Cell Balance Threshold at the start of every charge cycle. The threshold is only adjusted once during any

balance interval.

If the cells are severely imbalanced during charging, where VCELL(MAX) - VCELL(MIN) >Cell Imbalance Threshold

AND SBS. Current()> Balance IMAX for a period of Cell Imbalance time then the CIM bit in PF Status is set.

Table 6. Cell Balancing and Cell Imbalance Programming

NAME DF ADDRESS DESCRIPTION

Cell Balance Threshold 0xe8-0xe9 Sets the maximum voltage in mV that each cell must achieve to initiate cell balancing.

Programming Cell Balance Threshold to 65,535 disables cell balancing.

Cell Balance Min 0xec Sets in mV the cell differential that must exist to initiate cell balancing

Cell Balance Window 0xea-0xeb Sets in mV the amount that the cell balance threshold increases during cell balancing

Cell Balance Interval 0xed Sets the cell balancing time interval in seconds.

Cell Imbalance Threshold 0xee-0xef Sets the severe imbalance fault limit for cell imabalance detection

Balance IMAX 0xf2-0xf3 Sets the charge current required to allow a cell imbalance to be detected

Cell Imbalance Time 0x134 Sets the time period during which a cell imbalance must be selected for the bq2084 to enter

PF mode.

DISPLAY PORT

General

The display port drives a 3-, 4-, or 5-LED bar-graph display. The display is activated by a logic signal on the

DISP input. The bq2084-V133 can display RM in either a relative or absolute mode with each LED representing

a percentage of the full-battery reference. In relative mode, the bq2084-V133 uses FCC as the full-battery

reference; in absolute mode, it uses Design Capacity (DC). The DMODE bit in Pack Configuration (DF 0x28)

programs the bq2084-V133 for the absolute or relative display mode. The LED bits program the 3-, 4-, or 5-LED

option.

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Activation

The display may be activated at any time by a high-to-low transition on the DISP input. This is usually

accomplished with a pullup resistor and a pushbutton switch. Detection of the transition activates the display and

starts a 4-s display timer. Reactivation of the display requires that the DISP input return to a logic-high state and

then transition low again. The second high-to-low transition can be detected only after the display timer expires. If

unused, the DISP input must be pulled up to VCC. If the EDV0 bit is set, the bq2084-V133 disables the LED

display.

Display Modes

In relative mode, each LED output represents 20%, 25%, or 33% of the RelativeStateOfCharge() value. In

absolute mode, each LED output represents 20%, 25% or 33% of the AbsoluteStateOfCharge() value. Table 7

shows the display options for 5 LEDs, for 4 LEDs, Table 8 and Table 9 for 3 LEDs. In either mode, the

bq2084-V133 blinks the LED display if RemainingCapacity() is less than Remaining CapacityAlarm(). The display

is disabled if EDV0 = 1.

Table 7. Display Mode for Five LEDs

CONDITION FIVE-LED DISPLAY OPTION

RELATIVE OR ABSOLUTE

StateOfCharge() LED1 LED2 LED3 LED4 LED5

EDV0 = 1 OFF OFF OFF OFF OFF

<20% ON OFF OFF OFF OFF

≥20%, < 40% ON ON OFF OFF OFF

≥40%, < 60% ON ON ON OFF OFF

≥60%, < 80% ON ON ON ON OFF

≥80% ON ON ON ON ON

Table 8. Display Mode for Four LEDs

CONDITION FOUR-LED DISPLAY OPTION

RELATIVE OR ABSOLUTE

StateOfCharge() LED1 LED2 LED3 LED4

EDV0 = 1 OFF OFF OFF OFF

<25% ON OFF OFF OFF

≥25%, < 50% ON ON OFF OFF

≥50%, < 75% ON ON ON OFF

≥75% ON ON ON ON

Table 9. Display Mode for Three LEDs

CONDITION THREE-LED DISPLAY OPTION

RELATIVE OR ABSOLUTE

StateOfCharge() LED1 LED2 LED3

EDV0 = 1 OFF OFF OFF

<34% ON OFF OFF

≥34%, < 67% ON ON OFF

≥67% ON ON ON

LI-ION PROTECTION

The bq2084-V133 along with the bq29312 provides protection for Li-ion batteries, as shown in Table 10. The

bq2084-V133 measures temperature and current and uses the bq29312 to measure individual cell voltage. The

bq2084-V133 uses this information to determine protection requirements and control the safety FETs or SAFE

output as necessary. It is recommended that the bq2084-V133 protection control be validated by two successive

measurements by setting VOD=1 in Misc Configuration.

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The bq29312 can independently detect and protect the load from an overload (OL) or short circuit in charge

(SCC) or discharge (SCD). The bq29312 sets the appropriate FET state and then alerts the bq2084-V133 with

the XALERT output whenever a protection threshold is breached and its associated delay time has expired. The

bq2084-V133 then determines if and when the FETs should be turned back on.

Table 10. CVOV and CVUV Flags in PackStatus()

FLAG SET CONDITION DSG FET CHG FET CLEAR CONDITION(1)

Voltage() = ChargingVoltage() + Over ON OFF(2) Voltage() < ChargingVoltage()

Voltage Margin

CVOV VCELL(ANY) ≥Cell Over Voltage ON OFF(2) VCELL(ALL) <Cell Over Voltage Reset

VCELL(ANY) ≤Cell Under Voltage (3)ON VCELL(ALL) >Cell Under Voltage Reset

CVUV AverageCurrent() ≤Over Load Current OFF (3) ON AverageCurrent() ≤Current Fault Clear Threshold

(1) Clear is detected and controlled by the bq2084-V133.

(2) On if there is a discharge current ≥Discharge Detection Current

(3) On if there is a charge current ≥Charge Detection Current

Protection Configuration

1st Level Cell Voltage Thresholds

Cell under voltage is detected when any cell voltage is measured equal to or below the value programmed in Cell

Under Voltage for a minimum of 1s and maximum of 2s and recovers when all cell voltages are above Cell

Under Voltage Reset. Cell over voltage is detected when any cell voltage is measured equal to or above the

value programmed in Cell Over Voltage for a minimum of 1s and maximum of 2s and recovers when all cell

voltages are below Cell Over Voltage Reset.

The cell undervoltage (VUV) and overvoltage (VOV) limits are programmed in Cell Under Voltage and Cell Over

Voltage (DF 0x65-0x66, DF 0x63-0x64, (respectively). Both values are stored in mV. Cell Over Voltage Reset

(DF 0xe0-0xe1) and Cell Under Voltage Reset (DF 0xe2-0xe3) set the reset points in mV for these safety

parameters

Safety Overvoltage Threshold

The safety voltage threshold is programmed in Safety Over Voltage (DF 0x6b-0x6c). It is stored in mV.

Exceeding the Safety Voltage for a period determined by the MISC Config VOD bit causes permanent failure if

enabled by PFConfig.

Overcurrent Thresholds

A discharge over current fault is detected when the measured current is more negative than the value

programmed in Discharge OC Threshold for a period equal to of greater than the time programmed into

Discharge OC Time. When the fault is detected the DSG FET is turned OFF.

The DSG FET is turned back on when SBS.AverageCurrent( ) is less negative than the value programmed in

Current Fault Clear Threshold (DF 0x61, 0x62).

A charge over current fault is detected when the measured current is greater than the value programmed in

Charge OC Threshold for a period equal to of greater than the time programmed into Charge OC Time. When

the fault is detected the CHG FET is turned OFF.

The CHG FET is turned back on when SBS.AverageCurrent( ) is less than the value programmed in Current

Fault Clear Threshold (DF 0x61, 0x62).

Discharge current threshold is programmed in Discharge OC Threshold (DF 0x12d-0x12e). The discharge

overcurrent must exist for time programmed in Discharge OC Time (DF 0x12f). When a discharge overcurrent

condition is detected the discharge FET is turned off. Similarly, a charge overcurrent is programmed in Charge

OC Threshold (DF 0x12a-0x12b). The charge overcurrent must exist for the time programmed in Charge OC

Time (DF 0x12c) or Charge OC Time (DF 0x12c).

Note: See Table 10 for some special FET state conditions.

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Temperature Thresholds

The Safety Over Temperature in Charge (SOTC) threshold is programmed in Safety Over Temperature in

Charge (DF 0x75-0x76) and Safety Over Temperature in Discharge (SOTD) threshold is programmed in Safety

Over Temperature in Discharge (DF 0x77-0x78).

SOTC is stored as Safety Over Temperature in Charge = SOTC ÷ 0.1 (°C) as an unsigned integer

SOTD is stored as Safety Over Temperature in Discharge = SOTD ÷ 0.1 (°C) as an unsigned integer. Exceeding

the Safety Temperatures causes permanent failure if enabled by PFConfig.

There are also temperature thresholds to disable both charge and discharge FETs and to set the SBS Battery

Status Overtemperature bit. The thresholds are set according to whether discharge or charge is detected. The

Charge Suspend Temp High threshold is stored in DF 0x6d-0x6e with the reset threshold stored in DF 0x6f-0x70.

Likewise, the Over Temperature Discharge threshold is stored in DF 0x71-0x72 with the reset threshold stored in

DF 0x73-0x74.

The Charge Suspend Temp Low threshold (CSTL) is stored in Charge Suspend Temp Low (DF 0x79-0x7a) and

is stored as Charge Suspend Temp Low = CSTL ÷ 0.1 (°C) as a signed integer. A Charge Suspend Temp Low

turns off the charge FET. The maximal value of Charge Suspend Temp Low setting is 12.7 °C.

AFE Configuration

The AFE protection limits are programmed as specified in the bq29312 data sheet.

AFE Over Load (DF 0xc5) sets the AFE overload protection threshold.

AFE Over Load Delay (DF 0xc6) sets the delay timing for overload protection.

AFE Short Circuit in Charge (DF 0xc7) sets the AFE short circuit in charge protection threshold and delay

time.

AFE Short Circuit in Discharge (DF 0xc8) sets the AFE short circuit in discharge protection threshold and

delay time.

SMBus command 0x46 can be used to string-read the AFE RAM with the AFE address 0x00 first, if the

bq2084-V133 is not sealed as indicated by bit 5 of PackStatus.

Table 11. Overcurrent Protection

FAILURE FET STATUS CLEAR CONDITIONS

NR=1

AFE OLV CHG on, ZVCHG off, DSG off Same AFE SCD

Average Current ()< Clear Fail Current (DF 0x61/2) for

AFE SCC CHG off, ZVCHG off, DSG on Fault Reset Time (DF 0x130), or disharge current >

discharge detection current (DF 0x115/6)

Average Current () ≥-Clear Fail Current (DF 0x61/2) for

AFE SCD CHG on, ZVCHG off, DSG off Fault Reset Time (DF 0x130), or charge current > charge

detection current (DF 0x113/4)

GG Charge OC (set by DF 0x12a to 0x12c) CHG off, ZVCHG off, DSG on Same AFE SCC

GG Discharge OC (set by DF 0x12d to 0x12f) CHG on, ZVCHG off, DSG off Same AFE SCD

NR=0

FAILURE FET STATUS EXIT CONDITIONS

AFE OLV All FETs off RRES=high

AFE SCC All FETs off PRES=high

AFE SCD All FETs off PRES=high

GG Charge OC (set by DF 0x12a to 0x12c) All FETs off PRES=high

GG Discharge OC (set by DF 0x12d to 0x12f) All FETs off PRES=high

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AFE Integrity Check

The bq2084-V133 checks the programming of the AFE registers at a period determined by AFE Check Time (DF

0xfb). The units of the check period are seconds unless the bq2084-V133 is in sleep mode, in which case the

period is AFE Check Time xSleep Current Multiplier (DF 0xfd). If the data is not correct, the bq2084-V133

increments an internal counter until it reaches the AFE Fail Limit (DF 0xe4). Setting AFE Check Time to 0

disables this function.

When the internal AFE Fail counter reaches AFE Fail Limit, then the AFE bit in PF Status is set.

AFE Watchdog Fault and Clear

The bq29312 has a feature where the 32-kHz output (CLKOUT, pin 35) of the bq2084-V133 is used to drive its

internal clock. If this clock fails, a fault is declared in the AFE. See the bq29312 data sheet for further details.

The fault is cleared automatically on return of the 32-kHz input via the bq2084-V133 CLKOUT pin.

Permanent Failure Mode (SAFE Output)

The SAFE output of the bq2084-V133 provides an additional level of safety control. The active low safety output

can blow a fuse or control another switch on the basis of temperature, pack-voltage cell-voltage, CHG FET

Failure, severe cell imbalance, or an integrity check of the AFE and Data Flash configuration registers.

The bq2084-V133 can also activate the SAFE output and set the PF Flag based on the PFIN input. If this pin is

low for PFIN Time seconds ±1 s, then the PFIN bit in PF Status is set.

The SAFE output can be driven low in any of the following conditions, and the bq2084-V133 sets the PF Flag

be enabled or disabled for different safety option per the PF Config (DF 0x11f) register settings.

The SAFE output and PF Flag register can only be cleared using a series of ManufacturerAccess() commands.

Table 12. SAFE Activation Conditions(1)

CONDITION ACTIONS

Voltage() > Safety Over Voltage (DF 0x6b and 0x6c), SOV and PF set

Temperature() > Safety Over Temperature in Charge (DF 0x75 and 0x76) SOTC and PF set

Temperature() > Safety Over Temperature in Discharge (DF 0x77 and 0x78) SOTD and PF set

When Miscellaneous Configuration (0x2a) bit 13 AC is set, and the number of AFE failures has reached the AFE Fail AFE and PF set

Limit (DF 0xe4)

When VCELL(MAX) - VCELL(MIN) >Cell Imbalance Threshold (DF 0xee, 0xef) during charging CIM and PF set

If charge FET is off, and charge current greater than FET Fail charge current stored in DF 0x125-0x126 for the time FETF and PF set

determined by FET Fail time in DF 0x129, or if discharge FET is off and discharge current greater than FET Fail

discharge current stored in DF 0x127-0x128 for the time determined by FET Fail time in DF 0x129.

The PFIN input has detected a low state for PFIN Time in consecutive seconds, as determined by DF 0x120 PFIN, PF set

(1) SAFE output activated and PF Flag set only if enabled by PF Config (DF 0x0x11f)

Permanent Failure Status (PF Status)

PF Status DF 0x11d contains the flags for the cause of the permanent failure mode.

b7 b6 b5 b4 b3 b2 b1 b0

PFF PFIN FETF CIM AFE SOTD SOTC SOV

SOV

The SOV bit indicates a safety overvoltage occurred which if enabled by PF Config would cause the SAFE

output to activate.

0 SOV fault not detected (default)

1 SOV fault detected

SOTC

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The SOTC bit indicates a safety overtemperature in charge occurred which if enabled by PF Config would

cause the SAFE output to activate.

0 SOTC fault not detected (default)

1 SOTC fault detected

SOTD

The SOTD bit indicates a safety overtemperature in discharge occurred which if enabled by PF Config would

cause the SAFE output to activate.

0 SOTD fault not detected (default)

1 SOTD fault detected

AFE

The AFE bit indicates an AFE integrity fault state occurred which if enabled by PF Config would cause the

SAFE output to activate.

0 AFE is operating correctly (default)

1 AFE Integrity check fail limit reached

CIM

The CIM bit indicates that a severe cell imbalance occurred during charging, which if enabled by PF Config,

would cause the SAFE output to activate.

0 All cells are within the Cell Imbalance Threshold (default)

1 There is a severe cell imbalance

FETF

The FETF bit indicates a FET or FET driver failure occurred, which if enabled by PF Config would cause the

SAFE output to activate.

0 The FETs are operating normally (default)

1 The FETs or FET drivers have a fault

PFIN

The PFIN bit is used to indicate that the output of the 2nd level protector has activated.

0 The PFIN input is high (default)

1 The PFIN input drive and held low by 2nd level protector output

FPP

The FPP bit is used to indicate that current has been detected when the fuse has been set to be blown.

0 Current not detected with fuse blown

1 Current detected with fuse blown

Permanent Failure Configuration (PF Config)

PF Config (DF 0x11f) contains the enable/disable configuration that determines if the SAFE output is activated

and the PF Flag set for each possible failure mode.

b7 b6 b5 b4 b3 b2 b1 b0

- XPFIN XFETF XCIM XAFE XSOTD XSOTC XSOV

XSOV

The XSOV bit enables or disables the activation of SAFE and the setting of the PF Flag when PF Status SOV is

set.

0 Activation disabled (default)

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1 Activation enabled

XSOTC

The XSOTC bit enables or disables the activation of SAFE and the setting of the PF Flag when PF Status

SOTC is set.

0 Activation disabled (default)

1 Activation enabled

XSOTD

The XSOTD bit enables or disables the activation of SAFE and the setting of the PF Flag when PF Status

SOTD is set.

0 Activation disabled (default)

1 Activation enabled

XAFE

The XAFE bit enables or disables the activation of SAFE and the setting of the PF Flag when PF Status AFE is

set. Bit 13 of Miscellaneous Config DF 0x2a also needs to be set for activation.

0 Activation disabled (default)

1 Activation enabled

XCIM

The XCIM bit enables or disables the activation of SAFE and the setting of the PF Flag when PF Status CIM is

set.

0 Activation disabled (default)

1 Activation enabled

XFETF

The XFETF bit enables or disables the activation of SAFE and the setting of the PF Flag when PF Status FETF

is set.

0 Activation disabled (default)

1 Activation enabled

XPFIN

The XPFIN bit enables or disables the activation of SAFE and the setting of the PF Flag when PF Status PFIN

is set.

0 Activation disabled (default)

1 Activation enabled

Permanent Failure Flag (PF Flag)

PF Flag DF 0x11e contains the flag indicating if the /SAFE output has been activated.

STATE b7 b6 b5 b4 b3 b2 b1 b0

Clear00000000

Set01100110

PF FLAG

The PF Flag indicates that the SAFE output of the bq2084-V133 has been activated.

0x00 SAFE output high (default)

0x66 SAFE output activated

An example circuit using the SAFE output to blow a fuse is shown in Figure 2.

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Figure 2. Example SAFE Circuit Implementation

Low-Power Modes

The bq2084-V133 enters sleep mode when the charge and discharge current is less than the threshold

programmed in Sleep Current Threshold (DF 0xfc), the SMBus lines are low for at least 2s, and bit 12 of Misc.

Configuration DF 0x2a is set to zero. Additionally, PRES must be pulled high if the NR bit in Misc Config is set to

0. The bq2084-V133 wakes up periodically to monitor voltage and temperature and to apply self-discharge

adjustment. The sleep period is set in Sleep Timer DF 0xfe. The bq2084-V133 wakes up at a period set by Sleep

Current Multiplier DF 0xfd multiplied by Sleep Time to measure current. The bq2084-V133 comes out of sleep

when either of the SMBus lines go high or when the current is measured and it is greater than the Sleep Current

Threshold.

The sleep current threshold, SLP (mA), is stored in Sleep Current Thresh (DF 0xfc) as:

Sleep Current Thresh = SLP(mA) ÷ 0.5

The wake-up period for current measurement, WAT(s), is set using the following formula:

Sleep Current Multiplier x Sleep Time = WAT(s)

During sleep mode, both charge and discharge FETs are turned off if the NR bit in Misc Config is cleared. If the

bq2084-V133 is in Non-Removable mode where NR=1, then the discharge FET retains its state on entry to

sleep.

Shutdown Mode

The bq2084-V133 goes into shutdown, in which all FETs are turned off and the pack electronics are powered

down (including the bq2084-V133), when SBS.Voltage() falls below Shutdown Voltage (DF 0x7c-0x7d) and

Voltage at the Pack pin is less than VPACK threshold (DF 0x131, 0x132) both for 2 consecutive samples (1 to 2

s).

Vpack is programmed in units of 0.935 mV/count and has tolerance of ±6%. For example, to set 12 V as Vpack

Threshold, the program value should be 12000/0.935 = 12834.

When the DSG FET is turned on, the pack voltage is close to the battery voltage even with no charger attached.

Therefore, to enter shutdown, the Vpack threshold should be set higher than the shutdown threshold plus the

tolerance.

The bq2084-V133 can also be instructed to enter Shutdown mode via the ManufacturerAccess() command.

When the command is sent to the bq2084-V133, the bq29312 is instructed to enter shutdown mode by the

bq2084-V133. This forces the chipset into its lowest power mode. The bq2084-V133 does not issue a shutdown

command to the AFE unless the pack voltage is less than the Vpack Threshold. Program the Vpack threshold

higher than the SBS.Voltage() when ship command is issued. Exit from this mode is only achieved by application

of a charger.

Product Folder Link(s): bq2084-V133

SBS.VCELLx( ) Measured

SBS.PackVoltage( ) Measured

SBS.Voltage( ) calculated

SBS.Voltage( ) <=

DF.Shutdown

Threshold ?

Yes

Normal Operation

SBS.Current( ) <= 0?

Yes

bq2084 Enters Shutdown

Has Time since exit

from last Shutdown >

DF.Shutdown Timer?

Yes

SBS.PackVoltage( ) <

DF.Vpack Threshold ?

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After exiting shutdown mode, the bq2084-V133 does not enter the shutdown mode again until the Shutdown

Timer (DF 0x133, units are seconds) has expired even if the correct conditions are present. After the Shutdown

Timer has expired, the SMBus command or voltage and current conditions enables the bq2084-V133 to enter

shutdown mode.

DEFAULTS: Non-Removable Pack - DF.ShutdownVoltage = 2.8 V x Number of Series cells; DF.ShutdownTimer = 2 s

NOTE: VpackThreshold must be greater than Shutdown voltage + 6%.

Removable Pack - DF.ShutdownVoltage = 2.8 V x Number of Series cells; DF.ShutdownTimer = 20 s

NOTE: VpackThreshold must be greater than Shutdown voltage + 6%

Figure 3. Shutdown Flow Chart in Normal Operation

Product Folder Link(s): bq2084-V133

SBS MAC command 0x05

received

SBS.Current( ) <= 0?

Pack voltage < Vpack

threshold ?

bq2084 Enters Shutdown

Yes

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Figure 4. Shutdown Flow Chart in SBS MAC

Reset Conditions

On power up, the entire IC is reset and data is loaded from Data Flash to configure the SBS Data and the battery

management solution. On a partial reset (loss of VCC but RBI holds RAM valid), a limited number of locations

are taken. These actions are the following:

• The AFE registers are rewritten.

•PackStatus() EDV2 flag is cleared.

•BatteryStatus() DISCHARGING flag is cleared.

• The charger and alarm broadcast period is set to 10 seconds between broadcasts.

COMMUNICATION

The bq2084-V133 includes an SMBus communication port. The SMBus interface is a 2-wire bidirectional protocol

using the SMBC (clock) and SMBD (data) pins. The communication lines are isolated from VCC and may be

pulled up higher than VCC. Also, the bq2084-V133 does not pull these lines low if VCC to the part is zero. The

communication ports allow a host controller, an SMBus compatible device, or other processor to access the

memory registers of the bq2084-V133. In this way a system can efficiently monitor and manage the battery.

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SMBus

The SMBus interface is a command-based protocol. A processor acting as the bus master initiates

communication to the bq2084-V133 by generating a start condition. A start condition consists of a high-to-low

transition of the SMBD line while the SMBC is high. The processor then sends the bq2084-V133 device address

of 0001011 (bits 7-1) plus a R/W bit (bit 0) followed by an SMBus command code. The R/W bit (LSB) and the

command code instruct the bq2084-V133 to either store the forthcoming data to a register specified by the

SMBus command code or output the data from the specified register. The processor completes the access with a

stop condition. A stop condition consists of a low-to-high transition of the SMBD line while the SMBC is high.

With SMBus, the most-significant bit (MSB) of a data byte is transmitted first. In some instances, the

bq2084-V133 acts as the bus master. This occurs when the bq2084-V133 broadcasts charging requirements and

alarm conditions to device addresses 0x12 (SBS Smart Charger) and 0x10 (SBS Host Controller.)

SMBus Protocol

The bq2084-V133 supports the following SMBus protocols:

• Read word

• Write word

• Block read

A processor acting as the bus master uses the three protocols to communicate with the bq2084-V133. The

bq2084-V133 acting as the bus master uses the write word protocol.

The SMBD and SMBC pins are open drain and require external pullup resistors. A 1-MΩpulldown resistor in the

battery pack on SMBC and SMBD is required to ensure the detection of the SMBus off-state, the performance of

automatic offset calibration, and the initiation of the low-power sleep mode when the battery pack is removed.

SMBus Packet Error Checking

The bq2084-V133 supports packet error checking as a mechanism to confirm proper communication between it

and another SMBus device. Packet error checking requires that both the transmitter and receiver calculate a

packet error code (PEC) for each communication message. The device that supplies the last byte in the

communication message appends the PEC to the message. The receiver compares the transmitted PEC to its

PEC result to determine if there is a communication error.

PEC Protocol

The bq2084-V133 can receive or transmit data with or without PEC. Figure 5 shows the communication protocol

for the read word, write word, and read block messages without PEC. Figure 6 includes PEC.

In the read word protocol, the bq2084-V133 receives the PEC after the last byte of data from the host. If the host

does not support PEC, the last byte of data is followed by a stop condition. After receipt of the PEC, the

bq2084-V133 compares the value to its calculation. If the PEC is correct, the bq2084-V133 responds with an

ACKNOWLEDGE (ACK). If it is not correct, the bq2084-V133 responds with a NOT ACKNOWLEDGE (NACK)

and sets an error code. In the write word and block read, the host generates an ACK after the last byte of data

sent by the bq2084-V133. The bq2084-V133 then sends the PEC and the host acting as a master-receiver

generates a NACK and a stop condition.

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Figure 5. SMBus Communication Protocol Without PEC

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Figure 6. SMBus Communication Protocol With PEC

PEC Calculation

The basis of the PEC calculation is an 8-bit cyclic redundancy check (CRC-8) based on the polynomial C(X) =

X8 + X2 + X1 + 1. The PEC calculation includes all bytes in the transmission, including address, command, and

data. The PEC calculation does not include ACKNOWLEDGE, NOT ACKNOWLEDGE, start, stop, and repeated

start bits.

For example, the host requests RemainingCapacity() from the bq2084-V133. This includes the host following the

read word protocol. The bq2084-V133 calculates the PEC based on the following 5 bytes of data, assuming the

remaining capacity of the battery is 1001 mAh.

• Battery Address with R/W = 0: 0x16

• Command Code for RemainingCapacity(): 0x0f

• Battery Address with R/W = 1: 0x17

•RemainingCapacity(): 0x03e9

For 0x160f17e903, the bq2084-V133 transmits a PEC of 0xe8 to the host.

PEC Enable in Master Mode

The PEC for master mode broadcasts to the charger, host, or both can be enabled/disabled with the combination

of the bits HPE and CPE in Pack Configuration (DF 0x28).

SMBus On- and Off-State

The bq2084-V133 detects whether the SMBus enters the Off State by monitoring the SMBC and SMBD lines.

When both signals are continually low for at least 2.0 s, the bq2084-V133 detects the Off State. When the SMBC

and SMBD lines go high, the bq2084-V133 detects the On State and can begin communication within 1 ms.

One-MΩpulldown resistors on SMBC and SMBD are recommended for reliable Off State detection.

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Command Codes

The SMBus command codes are in (). Temperature(),Voltage(),Current(), and AverageCurrent(), performance

specifications are at bq29312 regulated VCC (V(REG)) and a temperature of -20°C to 85°C.

Manufacturer Access() (0x00)

Description: This function provides writable command codes to control the bq2084-V133 during normal

operation and pack manufacture. Writing the command code to SMB command 0x00 causes the following reads

with the SMB command 0x00 to return the word indicated in the table. The following commands are available:

COMMAND CODE NAME DESCRIPTION

0x0001 Device Type Returns IC part number so it can be read, i.e., 2084 (0x0824)

0x0002 Firmware Rev Returns firmware version so it can be read

0x0003 EDV Level Returns the pending end-of-discharge voltage level so it can be read

0x0004 Manufacturer Status Returns the battery system status so it can read

0x0005 SHIP Command Instructs the bq2084-V133 to instruct the bq29312 to enter ship mode

Instructs the bq2084-V133 to restrict access to those functions listed in Table 3. The

0x062b Seal bq2084-V133 completes the seal function and clears ManufacturerAccess().

The Manufacture Status word is defined as:

b15 b14 b13 b12 b11 b10 b9 b8

FET1 FET0 PF1 PF0 STATE3 STATE2 STATE1 STATE0

b7 b6 b5 b4 b3 b2 b1 b0

00001010

FET1, FET0

Indicated the state of the charge and discharge FETs

0,0 Both charge and discharge FETs are on.

0,1 Charge FET is off, discharge FET is on.

1,0 Both charge and discharge FETs are off.

1,1 Charge FET is on, discharge FET is off.

PF1, PF0

Indicates permanent failure cause when permanent failure indicated by STATE3-STATE0

0,0 Fuse is blown

0,1 Cell imbalance failure

1,0 Safety voltage failure

1,1 FET failure

STATE3, STATE2, STATE1, STATE0

Indicates battery state as defined in the State and Status bit Summary.

Purpose: The ManufacturerAccess() function provides the system host access to bq2084-V133 functions that

are not defined by the SBD.

SMBus protocol: Read or write word

Input/Output: Word

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Table 13. State and Status Bit Summary

CHG ZVCHG Power

State MAC Mode (MSB) CC() CV() DSG FET FUSE

FET(1) FET Mode

wakeup 0x00 Wake up 0 0 off(2) on on(3) ok normal

precharge 0x03 Precharge PC CV of(2)f on on(4) ok normal

chargesusp 0x04 Charge Suspension FC CV off on off ok normal

terminatecharge 0x07 Charge Terminate MC CV off on off ok normal

normalcharge 0x05 Charge FC(5) CV on on off ok normal

provisionalcharge 0 0 off on off ok normal

0x01 Normal

normaldischarge FC CV on on off ok normal

depleted PC CV off off off ok normal

depleted_ac PC CV off off off((4))ok normal

overheatdischarge FC CV off off off ok normal

0x0e System Present

overheatcharge FC CV off off off ok normal

battfail_overcharge 0 0 off on off ok normal

battfail_lowtemp 0 0 off on off ok normal

battfail_chargeterminate 0x08 Fault Charge Terminate 0 0 off on off ok normal

battfail_afe_chg 0 0 off of(6)f off ok normal

0x0c Battery Failure

battfail_afe_dsg FC CV off(6) off off ok normal

battfail_chg 0 0 off off(6) off ok normal

0x0a Over Current

battfail_dsg FC CV off(6) off off ok normal

removed 0x0f Battery Out FC CV off off off ok normal

sleep 0x0d Sleep 0 0 off off(7) off ok low

permanent_failure 0x09 Permanent Failure 0 0 off off off blow low

(1) CHG FET always on if discharge current greater than Discharge Detection Current (DF 0x115, 0x116)

(2) On if FET Config = 01 (Common precharge, charge FET)

(3) ZVCHG FET on, OD FET off if FET Config = 00 or 02 (ZVCHG FET or precharge FET)

(4) ZVCHG FET on, OD FET off if FET Config = 00 (ZVCHG FET), or ZVCHG FET off, OD FET on if FET Config = 02 (precharge FET)

(5) 0 if CVOV or PC is not CVOV and minimum cell voltage is less than the precharge cell voltage threshold

(6) If MiscConfig.Nonremoveable Battery is set, then FET is on.

RemainingCapacityAlarm() (0x01)

Description: Sets or gets the low-capacity threshold value. Whenever the RemainingCapacity() falls below the

low-capacity value, the bq2084-V133 sends AlarmWarning() messages to the SMBus host with the

REMAINING_CAPACITY_ALARM bit set. A low-capacity value of 0 disables this alarm. The bq2084-V133

initially sets the low-capacity value to Remaining Capacity Alarm value programmed in DF 0x02-0x03. The

low-capacity value remains unchanged until altered by the RemainingCapacityAlarm() function. The low-capacity

value may be expressed in either current (mA) or power (10 mWh) depending on the setting of the BatteryMode()

CAPACITY_MODE bit.

Purpose: The RemainingCapacityAlarm() function can be used by systems that know how much power they

require to save their operating state. It enables those systems to more finely control the point at which they

transition into suspend or hibernate state. The low-capacity value can be read to verify the value in use by the

bq2084-V133 low-capacity alarm.

SMBus protocol: Read or write word

Input/Output: Unsigned integer-value below which Low Capacity messages are sent.

BATTERY MODES

CAPACITY_MODE CAPACITY_MODE

BIT = 0 BIT = 1

Units mAh at C/5 10 mWh at P/5

Range 0-65,535 mAh 0-65,535 10 mWh

Granularity Not applicable

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BATTERY MODES

CAPACITY_MODE CAPACITY_MODE

BIT = 0 BIT = 1

Accuracy See RemainingCapacity()

RemainingTimeAlarm() (0x02)

Description: Sets or gets the Remaining Time Alarm value. Whenever the AverageTimeToEmpty() falls below

the remaining time value, the bq2084-V133 sends AlarmWarning() messages to the SMBus host with the

REMAINING_TIME_ALARM bit set. A remaining time value of 0 effectively disables this alarm. The bq2084-V133

initially sets the remaining time value to the Remaining Time Alarm (DF 0x00-0x01) value. The remaining time

value remains unchanged until altered by the RemainingTimeAlarm() function.

Purpose: The RemainingTimeAlarm() function can be used by systems that want to adjust when the remaining

time alarm warning is sent. The remaining time value can be read to verify the value in use by the bq2084-V133

RemainingTimeAlarm().

SMBus protocol: Read or write word

Input/Output: Unsigned integer—the point below which remaining time messages are sent.

Units: Minutes

Range: 0 to 65,535 minutes

Granularity: Not applicable

Accuracy: See AverageTimeToEmpty().

BatteryMode() (0x03)

Description: Selects the various battery operational modes and reports the battery's mode and requests.

Defined modes include

• Whether the battery capacity information is specified in units of mAh or 10 mWh (CAPACITY_MODE bit)

• Whether the ChargingCurrent() and ChargingVoltage() values are broadcast to the smart battery charger

when the CHARGER_MODE bit is set.

• Whether all broadcasts to the smart battery charger and host are disabled

The defined request condition is the battery requesting a conditioning cycle (RELEARN_FLAG).

Purpose: The CAPACITY_MODE bit allows power management systems to best match their electrical

characteristics with those reported by the battery. For example, a switching power supply represents a constant

power load, whereas a linear supply is better represented by a constant current model. The CHARGER_MODE

bit allows a SMBus host or smart battery charger to override the smart battery desired charging parameters by

disabling the bq2084-V133 broadcasts. The RELEARN_FLAG bit allows the bq2084-V133 to request a

conditioning cycle.

SMBus protocol: Read or write word

Input/Output: Unsigned integer—bit mapped—see Table 14.

Units: Not applicable

Range: 0-1

Granularity: Not applicable

Accuracy: Not applicable

The BatteryMode() word is divided into two halves, the MSB (bits 8-15) which is read/write and the LSB (bits 0-7)

which is read only. The bq2084-V133 forces bits 0-6 to zero and prohibits writes to bit 7.

Table 14 summarizes the meanings of the individual bits in the BatteryMode() word. Specified default values,

where applicable, are noted. INTERNAL_CHARGE_CONTROLLER bit is not used by the bq2084-V133.

PRIMARY_BATTERY_SUPPORT bit is not used by the bq2084-V133.

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RELEARN_FLAG bit set indicates that the bq2084-V133 is requesting a capacity relearn cycle for the battery.

The bq2084-V133 sets the RELEARN_FLAG on a full reset and if it detects 20-cycle counts without an FCC

update. The bq2084-V133 clears this flag after a learning cycle has been completed.

CHARGE_CONTROLLER_ENABLED bit is not used by the bq2084-V133. The bq2084-V133 forces this bit to

zero.

PRIMARY_BATTERY bit is not used by the bq2084-V133. The bq2084-V133 forces this bit to zero.

Table 14. Battery Mode Bits and Values

Battery Mode() BITS BITS USED FORMAT ALLOWABLE VALUES

INTERNAL_CHARGE_CONTROLLER 0 Read only bit flag 1 - always one

PRIMARY_BATTERY_SUPPORT 1 Read only bit flag 0 - always zero

Reserved 2-6 0 - always zero

RELEARN_FLAG 7 Read only bit flag 0—Battery OK1—Relearn cycle requested

CHARGE_CONTROLLER_ENABLED 8 R/W bit flag Not used

PRIMARY_BATTERY 9 R/W bit flag Not used

Reserved 10-12 0 - always zero

0—Enable alarm broadcast (default)1—Disable

ALARM_MODE 13 R/W bit flag alarm broadcast

0—Enable charging broadcast

CHARGER_MODE 14 R/W bit flag (default)1—Disable charging broadcast

0—Report in mA or mAh (default)1—Report in

CAPACITY_MODE 15 R/W bit flag 10 mW or 10 mWh

ALARM_MODE bit is set to disable the bq2084-V133s ability to master the SMBus and send AlarmWarning()

messages to the SMBus host and the smart battery charger. When set, the bq2084-V133 does not master the

SMBus, and AlarmWarning() messages are not sent to the SMBus host and the smart battery charger for a

period of no more than 60 s and no less than 59 s. When cleared (default), the smart battery sends the

AlarmWarning() messages to the SMBus host and the smart battery charger any time an alarm condition is

detected.

• The ALARM broadcast does not occur more often than once every 10 s. Whenever the BATTERY_MODE

command is received, the bq2084-V133 resets the bit and starts or restarts a 60-s (nominal) timer. After the

timer expires, the bq2084-V133 automatically enables alarm broadcasts to ensure that the accidental

deactivation of broadcasts does not persist. An SMBus host that does not want the bq2084-V133 to be a

master on the SMBus must therefore continually set this bit at least once per 59 s to keep the bq2084-V133

from broadcasting alarms.

• The ALARM_MODE bit defaults to a cleared state when the bq2084-V133 enters SLEEP mode.

• The condition of the ALARM-MODE bit does not affect the operation or state of the CHARGER_MODE bit,

which is used to prevent broadcasts of ChargingCurrent() and ChargingVoltage() to the smart battery charger.

CHARGER_MODE bit enables or disables the bq2084-V133's transmission of ChargingCurrent() and

ChargingVoltage() messages to the smart battery charger. When set, the bq2084-V133 does not transmit

ChargingCurrent() and ChargingVoltage() values to the smart battery charger. When cleared, the

bq2084-V133 transmits the ChargingCurrent() and ChargingVoltage() values to the smart battery charger.

The CHARGER_MODE bit defaults to a cleared state when the bq2084-V133 enters SLEEP mode.

CAPACITY_MODE bit indicates if capacity information is reported in mA/mAh or 10 mW/10 mWh. When set, the

bq2084-V133 reports capacity information in 10 mW/10 mWh as appropriate. When cleared, the bq2084-V133

reports capacity information in mA/mAh as appropriate. The CAPACITY_MODE bit defaults to a cleared state

when the bq2084-V133 enters SLEEP mode.

The following functions are changed to accept or return values in mA/mAh or 10 mW/10 mWh depending on the

CAPACITY_MODE bit:

•RemainingCapacityAlarm()

•AtRate()

•RemainingCapacity()

•FullChargeCapacity()

•DesignCapacity()

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The following functions are calculated on the basis of capacity and may be calculated differently depending on

the CAPACITY_MODE bit:

•AtRateOK()

•AtRateTimeToEmpty()

•AtRateTimeToFull()

•RunTimeToEmpty()

•AverageTimeToEmpty()

•AverageTimeToFull()

•Remaining Time Alarm()

•BatteryStatus()

The bq2084-V133 updates the non-AtRate related register values immediately after changing the state of the

CAPACITY_MODE bit. The AtRate() values are updated after the next AtRate() value is written to the

bq2084-V133 (or after the next 1-s scheduled refresh calculation).

AtRate() (0x04)

Description: The AtRate() function is the first half of a two-function call-set used to set the AtRate value used in

calculations made by the AtRateTimeToFull(),AtRateTimeToEmpty(), and AtRateOK() functions. The AtRate

value may be expressed in either current (mA) or power (10 mW) depending on the setting of the BatteryMode()

CAPACITY_MODE bit.

Purpose: Because the AtRate() function is the first half of a two-function call-set, it is followed by the second

function of the call-set that calculates and returns a value based on the AtRate value and the battery's present

state.

• When the AtRate() value is positive, the AtRateTimeToFull() function returns the predicted time to full charge

at the AtRate value of charge.

• When the AtRate() value is negative, the AtRateTimeToEmpty() function returns the predicted operating time

at the AtRate value of discharge.

• When the AtRate() value is negative, the AtRateOK() function returns a Boolean value that predicts the

battery's ability to supply the AtRate value of additional discharge energy (current or power) for 10 seconds.

The default value for AtRate() is zero.

SMBus protocol: Read or write word

Input/Output: Signed integer-charge or discharge; the AtRate() value is positive for charge, negative for

discharge, and zero for neither (default).

BATTERY MODES

CAPACITY_MODE CAPACITY_MODE

BIT = 0 BIT = 1

Units mA 10 mW

Charge range 1 to 32,767 mA 1 to 32,767 10 mW

Discharge range –1 to –32,768 mA –1 to –32,768 10 mW

Granularity 1 Unit

Accuracy NA

AtRateTimeToFull() (0x05)

Description: Returns the predicted remaining time to fully charge the battery at the AtRate() value (mA).

Purpose: The AtRateTimeToFull() function is part of a two-function call-set used to determine the predicted

remaining charge time at the AtRate value in mA. The bq2084-V133 updates AtRateTimeToFull() within 5 ms

after the SMBus host sets the AtRate value. The bq2084-V133 automatically updates AtRateTimeToFull() based

on the AtRate() value every 1 s.

SMBus protocol: Read word

Output: Unsigned integer—predicted time in minutes to fully charge the battery.

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Units: Minutes

Range: 0 to 65,534 min

Granularity: 2 min or better

Accuracy: ±MaxError() ×FullChargeCapacity() ÷ |AtRate()|

Invalid Data Indication: 65,535 indicates the AtRate = 0.

AtRateTimeToEmpty() (0x06)

Description: Returns the predicted remaining operating time if the battery is discharged at the AtRate() value.

Purpose: The AtRateTimeToEmpty() function is part of a two-function call-set used to determine the remaining

operating time at the AtRate() value. The bq2084-V133 updates AtRateTimeToEmpty() within 5 ms after the

SMBus host sets the AtRate() value. The bq2084-V133 automatically updates AtRateTimeToEmpty() based on

the AtRate() value every 1 s.

SMBus protocol: Read word

Output: Unsigned integer—estimated operating time left.

Units: Minutes

Range: 0 to 65,534 min

Granularity: 2 min or better

Accuracy: -0, +MaxError() ×FullChargeCapacity ÷ |AtRate()|

Invalid Data Indication: 65,535 indicates AtRate = 0.

AtRateOK() (0x07)

Description: Returns a Boolean value that indicates whether or not the battery can deliver the AtRate() value of

additional energy for 10 s. If the AtRate value is zero or positive, the AtRateOK() function ALWAYS returns OK

(logic 1).

Purpose: The AtRateOK() function is part of a two-function call-set used by power management systems to

determine if the battery can safely supply enough energy for an additional load. The bq2084-V133 updates

AtRateOK() within 5 ms after the SMBus host sets the AtRate() value. The bq2084-V133 automatically updates

AtRateOK() based on the At Rate() value every 1 second.

SMBus protocol: Read word

Output: Boolean—indicates if the battery can supply the additional energy requested.

Units: Boolean

Range: 1, 0

Granularity: Not applicable

Accuracy: Not applicable

Temperature() (0x08)

Description: Returns the temperature (K) measured by the bq2084-V133.

Purpose: The Temperature() function provides accurate cell temperatures for use by battery chargers and

thermal management systems. A battery charger can use the temperature as a safety check. Thermal

management systems may use the temperature because the battery is one of the largest thermal sources in a

system.

SMBus protocol: Read word

Output: Unsigned integer—cell temperature in tenth-degree Kelvin increments.

Units: 0.1°K

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Range: 0 to +6553.5°K {real range}

Granularity: 0.1°K

Accuracy: ±1.5°K (from ideal Semitec 103AT thermistor performance, after calibration)

Voltage() (0x09)

Description: Returns the cell-pack voltage (mV).

Purpose: The Voltage() function provides power management systems with an accurate battery terminal voltage.

Power management systems can use this voltage, along with battery current information, to characterize devices

they control. This ability helps enable intelligent, adaptive power-management systems.

SMBus protocol: Read word

Output: Unsigned integer—battery terminal voltage in mV.

Units: mV

Range: 0 to 20,000 mV

Granularity: 1 mV

Accuracy: ±0.25% (after calibration)

Current() (0x0a)

Description: Returns the current being supplied (or accepted) by the battery (mA).

Purpose: The Current() function provides a snapshot for the power management system of the current flowing

into or out of the battery. This information is of particular use in power-management systems because they can

characterize individual devices and tune their operation to actual system power behavior.

SMBus protocol: Read word

Output: Signed integer—charge/discharge rate in mA increments: positive for charge, negative for discharge.

Units: mA

Range: -32,768 to 32,767 mA

Granularity: 1 mA

Accuracy: 0.25% or 5 mA, whichever is greater

AverageCurrent() (0x0b)

Description: Returns a value that approximates a one-minute rolling average of the current being supplied (or

accepted) through the battery terminals (mA). AverageCurrent() is implemented as a single pole IIR filter with a

14.5-s time constant.

Purpose: The AverageCurrent() function provides the average current flowing into or out of the battery for the

power management system.

SMBus protocol: Read word

Output: Signed integer—charge/discharge rate in mA increments: positive for charge, negative for discharge.

Units: mA

Range: -32,768 to 32,767 mA

Granularity: 1 mA

Accuracy: 0.25% or 5 mA, whichever is greater

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MaxError() (0x0c)

Description: Returns the expected margin of error (%) in the state of charge calculation. For example, when

MaxError() returns 10% and RelativeStateOfCharge() returns 50%, the RelativeStateOfCharge() is more likely

between 50% and 60%. The bq2084-V133 sets MaxError() to 100% on a full reset. The bq2084-V133 sets

MaxError() to 2% on completion of a learning cycle, unless the bq2084-V133 limits the learning cycle to the

+512/-256 mAh maximum adjustment values. If the learning cycle is limited, the bq2084-V133 sets MaxError() to

8% unless MaxError() was already below 8%. In this case, MaxError() does not change. The bq2084-V133

increments MaxError() by 1% after four increments of CycleCount() without a learning cycle. If voltage-based

corrections are applied to the coulomb counter, MaxError() is set to 25%.

Purpose: The MaxError() function has real value in two ways: first, to give the user a confidence level about the

state of charge and second, to give the power management system information about how aggressive it should

be, particularly as the battery nears the end of its life.

SMBus protocol: Read word

Output: Unsigned integer—percent uncertainty for selected information.

Units: %

Range: 2-100%

Granularity: 1%

Accuracy: Not applicable

RelativeStateOfCharge() (0x0d)

Description: Returns the predicted remaining battery capacity expressed as a percentage of

FullChargeCapacity() (%).

Purpose: The RelativeStateOfCharge() function is used to estimate the amount of charge remaining in the

battery relative to the last learned capacity.

SMBus protocol: Read word

Output: Unsigned integer-percent of remaining capacity.

Units: %

Range: 0-100%

Granularity: 1%

Accuracy: -0, +MaxError()

AbsoluteStateOfCharge()(0x0e)

Description: Returns the predicted remaining battery capacity expressed as a percentage of DesignCapacity()

(%). Note that AbsoluteStateOfCharge() can return values greater than 100%.

Purpose: The AbsoluteStateOfCharge() function is used to estimate the amount of charge remaining in the

battery relative to the nominal or DesignCapacity().

SMBus protocol: Read word

Output: Unsigned integer—percent of remaining capacity.

Units: %

Range: 0-100+%

Granularity: 1%

Accuracy: -0, +MaxError()

RemainingCapacity() (0x0f)

Description: Returns the predicted charge or energy remaining in the battery. The RemainingCapacity() value is

expressed in either charge or energy, depending on the setting of the BatteryMode() CAPACITY_MODE bit.

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Purpose: The RemainingCapacity() function returns the battery's remaining capacity. This information is a

numeric indication of remaining charge or energy given by the AbsoluteStateOfCharge() or

RelativeStateOfCharge() functions and may be in a better form for use by power management systems.

SMBus protocol: Read word

Output: Unsigned integer—remaining charge in units of mAh or 10 mWh.

BATTERY MODES

CAPACITY_MODE CAPACITY_MODE

BIT = 0 BIT = 1

Units mAh 10 mWh

Range 0-65,535 mAh 0-65,535 10 mWh

Granularity mAh 10 mWh

Accuracy -0, +MaxError() * FullCharageCapacity()

FullChargeCapacity() (0x10)

Description: Returns the predicted pack capacity when it is fully charged. The FullChargeCapacity() value is

expressed in either current (mAh at a C/5 discharge rate) or power (10 mWh at a P/5 discharge rate) depending

on the setting of the BatteryMode() CAPACITY_MODE bit.

Purpose: The FullChargeCapacity() function provides a means of understanding the tank size of the battery.

This information, along with information about the original capacity of the battery, indicates battery wear.

SMBus protocol: Read word

Output: Unsigned integer—estimated full-charge capacity in units of mAh or 10 mWh.

BATTERY MODES

CAPACITY_MODE CAPACITY_MODE

BIT = 0 BIT = 1

Units mAh 10 mWh

Range 0-65,535 mAh 0-65,535 10 mWh

Granularity mAh 10 mWh

Accuracy -0, +MaxError() × FullCharageCapacity()

RunTimeToEmpty() (0x11)

Description: Returns the predicted remaining battery life at the present rate of discharge (minutes).

TheRunTimeToEmpty() value is calculated based on either current or power depending on the setting of the

BatteryMode() CAPACITY_MODE bit.

Purpose: The RunTimeToEmpty() provides the power management system with information about the relative

gain or loss in remaining battery life in response to a change in power policy. This information is not the same as

the AverageTimeToEmpty(), which is not suitable to determine the effects that result from a change in power

policy.

SMBus protocol: Read word

Output: Unsigned integer—minutes of operation left.

Units: Minutes

Range: 0 to 65,534 min

Granularity: 2 min or better

Accuracy: -0, +MaxError() ×FullChargeCapacity() ÷Current()

Invalid Data Indication: 65,535 indicates battery is not being discharged.

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AverageTimeToEmpty() (0x12)

Description: Returns a predicted remaining battery life (minutes), based on AverageCurrent. The

AverageTimeToEmpty() value is calculated based on either current or power depending on the setting of the

BatteryMode() CAPACITY_MODE bit.

Purpose: The AverageTimeToEmpty() displays state-of-charge information in a more useful way. It averages the

instantaneous estimations so that the remaining time does not appear to jump around.

SMBus protocol: Read word

Output: Unsigned integer—minutes of operation left.

Units: Minutes

Range: 0 to 65,534 min

Granularity: 2 min or better

Accuracy: -0, +MaxError() *FullChargeCapacity() /AverageCurrent()

Invalid Data Indication: 65,535 indicates battery is not being discharged.

AverageTimeToFull() (0x13)

Description: Returns a predicted remaining time until the battery reaches full charge (minutes), based on

AverageCurrent.

Purpose: The AverageTimeToFull() function can be used by the SMBus host's power management system to

aid in its policy. It may also be used to find out how long the system must be left on to achieve full charge.

SMBus protocol: Read word

Output: Unsigned integer—remaining time in minutes.

Units: Minutes

Range: 0 to 65,534 minutes

Granularity: 2 minutes or better

Accuracy: -0, +MaxError() *FullChargeCapacity() ÷AverageCurrent()

Invalid Data Indication: 65,535 indicates the battery is not being charged.

ChargingCurrent() (0x14)

Description: Returns the desired charging rate in mA.

Purpose: The ChargingCurrent() function sets the maximum charge current of the battery. TheChargingCurrent()

value should be used in combination with the ChargingVoltage() value to set the charger's operating point.

Together, these functions permit the bq2084-V133 to dynamically control the charging profile (current/voltage) of

the battery. The bq2084-V133 can effectively turn off a charger by returning a value of 0 for this function. The

charger may be operated as a constant-voltage source above its maximum regulated current range by returning

aChargingCurrent() value of 65,535.

SMBus protocol: Read word

Output: Unsigned integer—maximum charger output current in mA.

Units: mA

Range: 0 to 65,535 mA

Granularity: 1 mA

Accuracy: Not applicable

Invalid Data Indication: 65,535 indicates that a charger should operate as a voltage source outside its

maximum regulated current range.

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SLUS640B –JUNE 2005–REVISED FEBRUARY 2010

ChargingVoltage() (0x15)

Description: Returns the desired charging voltage in mV.

Purpose: The ChargingVoltage() function sets the maximum charge voltage of the battery. The

ChargingVoltage() value should be used in combination with the ChargingCurrent() value to set the charger's

operating point. Together, these functions permit the bq2084-V133 to dynamically control the charging profile

(current/voltage) of the battery. The charger may be operated as a constant-current source above its maximum

regulated voltage range by returning a ChargingVoltage() value of 65,535.

SMBus protocol: Read word

Output: Unsigned integer—charger output voltage in mV.

Units: mV

Range: 0 to 65,535 mV

Granularity: 1 mV

Accuracy: Not applicable

Invalid Data Indication: 65,535 indicates the charger should operate as a current source outside its maximum

regulated voltage range.

BatteryStatus() (0x16)

Description: Returns the bq2084-V133 status word (flags). Some of the BatteryStatus() flags (and

REMAINING_TIME_ALARM) are calculated on the basis of either current or power depending on the setting of

the BatteryMode() CAPACITY_MODE bit. This is important because use of the wrong calculation mode may

result in an inaccurate alarm.

Purpose: The BatteryStatus() function is used by the power management system to get alarm and status bits, as

well as error codes from the bq2084-V133. This is basically the same information broadcast to both the SMBus

host and the smart battery charger by the AlarmWarning() function except that the AlarmWarning() function sets

the error code bits all high before sending the data.

SMBus protocol: Read word

Output: Unsigned Integer-status register with alarm conditions bit-mapped as follows:

ALARM BITS

0x8000 OVER_CHARGED_ALARM

0x4000 TERMINATE_CHARGE_ALARM

0x2000 Reserved

0x1000 OVER_TEMP_ALARM

0x0800 TERMINATE_DISCHARGE_ALARM

0x0400 Reserved

0x0200 REMAINING_CAPACITY_ALARM

0x0100 REMAINING_TIME_ALARM

STATUS BITS

0x0080 Initialized

0x0040 DISCHARGING

0x0020 FULLY_CHARGED

0x0010 FULLY_DISCHARGED

ERROR CODES

0x0007 Unknown Error

0x0006 BadSize

0x0005 Overflow/Underflow

0x0004 AccessDenied

0x0003 UnsupportedCommand

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ALARM BITS

0x0002 ReservedCommand

0x0001 Busy

0x0000 OK

ALARM BITS

OVER_CHARGED_ALARM bit is set whenever the bq2084-V133 detects that the battery is being charged

beyond the maximum overcharge limit, which is full capacity plus Maximum Overcharge (DF 0x51-0x52). This bit

is cleared when the bq2084-V133 detects that the battery is no longer being charged and there are 2 mAh of

continuous discharge (i.e., the bq2084-V133 detects discharge activity or no activity above the digital filter).

TERMINATE_CHARGE_ALARM bit is set when the bq2084-V133 detects a primary charge termination. This bit

is cleared when the bq2084-V133 detects that the battery is no longer being charged.

OVER_TEMP_ALARM bit is set when the bq2084-V133 detects that the internal battery temperature is greater

than or equal to the OverTemperature Charge threshold while charging or OverTemperature Discharge threshold

while discharging. This bit is cleared when the internal temperature falls back below the OverTemperature

Charge Reset or OverTemperature Discharge Reset as appropiate..

TERMINATE_DISCHARGE_ALARM bit is set when RM = 0, Voltage() =Terminate Voltage (DF 0x67-0x68), the

battery temperature is less than or equal to the Charge Suspend Temp Low (DF 0x79) or the CVUV bit in pack

status is set indicating that a Li-ion cell voltage has dropped below the limit programmed in Cell Under. The bit is

cleared when Voltage() > Terminate Voltage,RM() > 0, and the CVUV bit is cleared.

REMAINING_CAPACITY_ALARM bit is set when the bq2084-V133 detects that RemainingCapacity() is less than

that set by the RemainingCapacityAlarm() function. This bit is cleared when either the value set by the

RemainingCapacityAlarm() function is lower than the RemainingCapacity() or when the RemainingCapacity() is

increased by charging.

REMAINING_TIME_ALARM bit is set when the bq2084-V133 detects that the estimated remaining time at the

present discharge rate is less than that set by the RemainingTimeAlarm() function. This bit is cleared when either

the value set by the RemainingTimeAlarm() function is lower than the AverageTimeToEmpty() or when the

AverageTimeToEmpty() is increased by charging.

STATUS BITS

The initialized bit is set when the bq2084-V133 has detected a valid load of data flash at full or partial reset. It is

cleared when the bq2084-V133 detects an improper data flash load.

DISCHARGING bit is set when the bq2084-V133 determines that the battery is not being charged. This bit is

cleared when the bq2084-V133 detects that the battery is being charged.

FULLY_CHARGED bit is set when the bq2084-V133 detects a primary charge termination or an Overcharge

condition. It is cleared when RelativeStateOfCharge() is less than the programmed Fully Charged Clear % (DF

0x4a).

FULLY_DISCHARGED bit is set when Voltage() or VCELL is less than the EDV2 threshold and Current() <

Overload Current or when RelativeStateOfCharge() <Battery Low %. This bit is cleared when

RelativeStateOfCharge() is greater than or equal to 20%.

ERROR CODES

ERROR CODES DESCRIPTION

OK The bq2084-V133 processed the function code without detecting any errors.

Busy The bq2084-V133 is unable to process the function code at this time.

The bq2084-V133 detected an attempt to read or write to a function code reserved by this version of the

Reserved specification.

The bq2084-V133 detected an attempt to access an unsupported optional manufacturer function code.

Unsupported The bq2084-V133 does not support this function code which is defined in this version of the specification.

AccessDenied The bq2084-V133 detected an attempt to write to a read-only function code.

Oveflowr/Underflow The bq2084-V133 detected a data overflow or underflow.

Product Folder Link(s): bq2084-V133

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SLUS640B –JUNE 2005–REVISED FEBRUARY 2010

ERROR CODES DESCRIPTION

BadSize The bq2084-V133 detected an attempt to write to a function code with an incorrect data block.

UnknownError The bq2084-V133 detected an unidentifiable error.

CycleCount()(0x17)

Description: Returns the number of cycles the battery has experienced. The mAh value of each count is

determined by programming the Cycle Count Threshold value in DF 0x38-0x39. The bq2084-V133 saves the

cycle count value to Cycle Count (DF 0x0c-0x0d) after an update to CycleCount().

Purpose: The CycleCount() function provides a means to determine the battery wear. It may be used to give

advance warning that the battery is nearing its end of life.

SMBus protocol: Read word

Output: Unsigned integer—count of total charge removed from the battery over its life.

Units: cycle

Range: 0 to 65,534 cycles; 65,535 indicates battery has experienced 65,535 or more cycles.

Granularity: 1 cycle

Accuracy: Absolute count

DesignCapacity() (0x18)

Description: Returns the theoretical or nominal capacity of a new pack. The DesignCapacity() value is

expressed in either current (mAh at a C/5 discharge rate) or power, (10 mWh at a P/5 discharge rate) depending

on the setting of the BatteryMode() CAPACITY_MODE bit.

Purpose: The DesignCapacity() function is used by the SMBus host's power management along with

FullChargeCapacity() to determine battery wear. The power management system may present this information to

the user and also adjust its power policy as a result.

SMBus protocol: Read word

Output: Unsigned integer—battery capacity in units of mAh or 10 mWh.

BATTERY MODES

CAPACITY_MODE CAPACITY_MODE

BIT = 0 BIT = 1

Units mAh 10 mWh

Range 0-65,535 mAh 0-65,535 10 mWh

Granularity Not applicable Not applicable

Accuracy Not applicable Not applicable

DesignVoltage() (0x19)

Description: Returns the theoretical voltage of a new pack (mV). The bq2084-V133 sets DesignVoltage() to the

value programmed in Design Voltage DF 0x04-0x05.

Purpose: The DesignVoltage() function can be used to give additional information about a particular smart

battery expected terminal voltage.

SMBus protocol: Read word

Output: Unsigned integer—the battery's designed terminal voltage in mV

Units: mV

Range: 0 to 65,535 mV

Granularity: Not applicable

Accuracy: Not applicable

Product Folder Link(s): bq2084-V133

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SpecificationInfo() (0x1a)

Description: Returns the version number of the smart battery specification the battery pack supports, as well as

voltage and current scaling information in a packed unsigned integer. Power scaling is the product of the voltage

scaling times the current scaling. The SpecificationInfo() is packed in the following fashion:

(SpecID_H × 0x10 + SpecID_L) + (VScale + IPScale × 0x10) × 0x100.

The bq2084-V133 VScale (voltage scaling) and IPScale (current scaling) should always be set to zero. The

bq2084-V133 sets SpecificationInfo() to the value programmed in Specification Information (DF 0x06-0x07).

Purpose: The SpecificationInfo() function is used by the SMBus host's power management system to determine

what information the smart battery can provide.

SMBus protocol: Read word

Output: Unsigned integer—packed specification number and scaling information:

FIELD BITS USED FORMAT ALLOWABLE VALUES

SpecID_L 0...3 4-bit binary value 0–15

SpecID_H 4...7 4-bit binary value 0–15

VScale 8...11 4-bit binary value 0 (multiplies voltage by 10^ VScale)

IPScale 12...15 4-bit binary value 0 (multiplies current by 10 ^ IPScale)

ManufactureDate() (0x1b)

Description: This function returns the date the cell pack was manufactured in a packed integer. The date is

packed in the following fashion: (year-1980) × 512 + month × 32 + day. The bq2084-V133 sets

ManufactureDate() to the value programmed in Manufacture Date (DF 0x08-0x09).

Purpose: The ManufactureDate() provides the system with information that can be used to uniquely identify a

particular battery pack when used along with SerialNumber().

SMBus protocol: Read word

Output: Unsigned integer-packed date of manufacture:

FIELD BITS USED FORMAT ALLOWABLE VALUES

Day 0...4 5-bit binary value 0-31 (corresponds to date)

Month 5...8 4-bit binary value 1-12 (corresponds to month number)

Year 9...15 7-bit binary value 0-127 (corresponds to year biased by 1980)

SerialNumber() (0x1c)

Description: This function is used to return a serial number. This number, when combined with the

ManufacturerName(), the DeviceName(), and the ManufactureDate(), uniquely identifies the battery (unsigned

integer). The bq2084-V133 sets SerialNumber() to the value programmed in Serial Number (DF 0x0a-0x0b).

Purpose: The SerialNumber() function can be used to identify a particular battery. This may be important in

systems that are powered by multiple batteries where the system can log information about each battery that it

encounters.

SMBus protocol: Read word

Output: Unsigned integer

ManufacturerName() (0x20)

Description: This function returns a character array containing the battery manufacturer's name. For example,

MyBattCo identifies the smart battery manufacturer as MyBattCo. The bq2084-V133 sets ManufacturerName() to

the value programmed in Manufacturer Name (DF 0x0e-0x19).

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Purpose: The ManufacturerName() function returns the name of the smart battery manufacturer. The

manufacturer's name can be displayed by the SMBus host's power management system display as both an

identifier and as an advertisement for the manufacturer. The name is also useful as part of the information

required to uniquely identify a battery.

SMBus protocol: Read block

Output: String—character string with maximum length of 11 characters (11 + length byte).

DeviceName() (0x21)

Description: This function returns a character string that contains the battery name. For example, a

DeviceName() of bq2084-V133 indicates that the battery is a model bq2084-V133. The bq2084-V133 sets

DeviceName() to the value programmed in Device Name (DF 0x1a-0x21).

Purpose: The DeviceName() function returns the battery name for identification purposes.

SMBus protocol: Read block

Output: String—character string with maximum length of 7 characters (7 + length byte).

DeviceChemistry() (0x22)

Description: This function returns a character string that contains the battery chemistry. For example, if the

DeviceChemistry() function returns NiMH, the battery pack contains nickel metal hydride cells. The bq2084-V133

sets DeviceChemistry() to the value programmed in Device Chemistry (DF 0x22-0x26).

Purpose: The DeviceChemistry() function gives cell chemistry information for use by charging systems. The

bq2084-V133 does not use DeviceChemisty() values for internal charge control or fuel gauging.

SMBus protocol: Read block

Output: String—character string with maximum length of 4 characters (4 + length byte).

The following is a partial list of chemistries and their expected abbreviations. These abbreviations are not case

sensitive.

CHEMISTRY ABBREVIATIONS

Lead acid PbAc

Lithium ion LION

Nickel cadmium NiCd

Nickel metal hydride NiMH

Nickel zinc NiZn

Rechargeable alkaline-manganese RAM

Zinc air ZnAr

The ManufacturerData() (0x23)

Description: This function allows access to the manufacturer data contained in the battery (data). The

bq2084-V133 stores seven critical operating parameters in this data area.

Purpose: The ManufacturerData() function may be used to access the manufacturer's data area. The data fields

of this command reflect the programming of eight critical data flash locations and can be used to facilitate

evaluation of the bq2084-V133 under various programming sets. The ManufacturerData() function returns the

following information in order: Pack Configuration, Gauge Configuration, Misc Configuration (2 bytes), Digital

Filter, Self Discharge Rate, Pack Load Estimate, Battery Low%, and Near Full (2 bytes) AFE Status, and the

pending EDV threshold voltage (low byte and high byte).

SMBus protocol: Read block

Output: Block data—data that reflects data flash programming as assigned by the manufacturer with maximum

length of 13 characters (13 + length byte).

Product Folder Link(s): bq2084-V133

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Pack Status and Pack Configuration (0x2f)

This function returns the pack status and pack configuration registers. The pack status register contains a

number of status bits relating to bq2084-V133 operation. The pack status register is the least significant byte of

the word. The pack configuration register reflects how the bq2084-V133 is configured as defined by the value

programmed in Pack Configuration in DF 0x28.

The pack status register consists of the following bits:

b7 b6 b5 b4 b3 b2 b1 b0

PRES EDV2 SS VDQ AFEFAIL PF CVOV CVUV

PRES

The PRES bit indicates that the bq2084-V133 has been inserted into the system.

0 bq2084-V133 is out of the system

1 bq2084-V133 is inserted into a system

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EDV2

The EDV2 bit indicates that pack or cell voltage (program option) is less than the EDV2 threshold.

0 Voltage > EDV2 threshold (discharging)

1 Voltage = EDV2 threshold

The SS bit indicates the seal state of the bq2084-V133.

0 The bq2084-V133 is in the unsealed state.

1 The bq2084-V133 is in the sealed state.

AFEFAIL

The AFEFAIL bit indicates that AFE communications has failed.

0 AFE communications are okay.

1 AFE communications have failed.

VDQ

The VDQ bit indicates if the present discharge cycle is valid for an FCC update.

0 Discharge cycle not valid

1 Discharge cycle valid

The PF bit indicates that the bq2084-V133 PF Flag has been set. It is cleared only when the PF Flag has been

cleared.

0 bq2084-V133 PF Flag = 0x00

1 bq2084-V133 PF Flag = 0x66

CVOV

The CVOV bit indicates that a protection limit has been exceeded including Prolonged Overcurrent,

Overvoltage, or Overtemperature conditions. The bit is not latched and merely reflects the present fault status.

0 No secondary protection limits exceeded

1 A secondary protection limit exceeded

CVUV

The CVUV bit indicates that a protection limit has been exceeded including overload or overdischarge

conditions. The bit is not latched and merely reflects the present fault status.

0 No secondary protection limits exceeded

1 A secondary protection limit exceeded

VCELL4-VCELL1 (0x3c-0x3f)

These functions return the calculated individual cell voltages in mV.

DATA FLASH

General

The bq2084-V133 accesses the internal data flash during reset and when storing historical data. The data flash

stores basic configuration information for use by the bq2084-V133. The data flash must be programmed correctly

for proper bq2084-V133 operation.

Product Folder Link(s): bq2084-V133

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Memory Map

The following table shows the memory map for the data flash. It shows the default programming for the

bq2084-V133. The default programming reflects example data for a 3s2p Li-ion battery pack with a 0.02-Ωsense

resistor. The data flash must be reprogrammed to meet the requirements of individual applications.

DATA FLASH ADDRESS DATA

NAME LI-ION EXAMPLE

HIGH BYTE LOW BYTE MSB LSB

0x00 0x01 Remaining Time Alarm 10 minutes 00 0a

0x02 0x03 Remaining Capacity Alarm 360 mAh 01 68

0x04 0x05 Design Voltage 14400 mV 38 40

0x06 0x07 Specification Information v1.1/PEC 00 31

0x08 0x09 Manufacture Date 1/1/2003=11809 2e 21

0x0a 0x0b Serial Number 1 00 01

0x0c 0x0d Cycle Count 0 00 00

0x0e Manufacturer Name Length 11 0b

0x0f Character 1 T 54

0x10 Character 2 e 45

0x11 Character 3 x 58

0x12 Character 4 a 41

0x13 Character 5 s 53

0x14 Character 6 20

0x15 Character 7 I 49

0x16 Character 8 n 4e

0x17 Character 9 s 53

0x18 Character 10 t 54

0x19 Character 11 . 2e

0x1a Device Name Length 6 06

0x1b Character 1 b 42

0x1c Character 2 q 51

0x1d Character 3 2 32

0x1e Character 4 0 30

0x1f Character 5 8 38

0x20 Character 6 4 34

0x21 Character 7 — 00

0x22 Device Chemistry Length 4 04

0x23 Character 1 L 4c

0x24 Character 2 I 49

0x25 Character 3 O 4f

0x26 Character 4 N 4e

0x27 Manufacturer Data Length 9 09

0x28 Pack Configuration DMODE, 4-LEDs, 4-CELL c3

0x29 Gauge Configuration CSYNC, OTVC 41

0x2a 0x2b Misc Configuration OT, VOD 0b 00

0x2c Digital Filter (Dead Band) 9860 nV 22

0x2d Self-Discharge Rate 0.2% 14

0x2e Electronics Load 0 mA 00

0x2f Battery Low % (MSB) 7.03% 12

0x30 0x31 Near Full 200 mAh 00 c8

0x32 0x33 Design Capacity 7200 mAh 1c 20

0x34 0x35 Reserved 0 00 00

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SLUS640B –JUNE 2005–REVISED FEBRUARY 2010

DATA FLASH ADDRESS DATA

NAME LI-ION EXAMPLE

HIGH BYTE LOW BYTE MSB LSB

0x36 0x37 Full Charge Capacity 7200 mAh 1c 20

0x38 0x39 Cycle Count Threshold 5200 mAh 14 50

0x3a 0x3b Charging Voltage 16800 mV 41 a0

0x3c 0x3d Precharge Voltage 2500 mV 09 c4

0x3e 0x3f Fast-Charging Current 2500 mA 09 c4

0x40 0x41 Maintenance Charging Current 0 mA 00 00

0x42 0x43 Precharge Current 100 mA 00 64

0x44 Precharge Temperature 9.6°C 60

0x45 Precharge Temperature Hysteresis 3.0°C 1e

0x46 Charge Inhibit Temp Low 0.0°C 00

0x47 0x48 Charge Inhibit Temp High 50.0°C 01 f4

0x49 Fast Charge Termination % 100% ff

0x4a Fully Charged Clear % 95% 5f

0x4b 0x4c Current Taper Threshold 240 mA 00 f0

0x4d 0x4e Current Taper Qual Voltage 300 mV 01 2c

0x4f Current Taper Window 40s 28

0x50 Reserved 40

0x51 0x52 Maximum Overcharge 300 mAh 01 2c

0x53 Reserved 02

0x54 Charge Efficiency 100% ff

0x55 Reserved 64

0x56 0x57 Reserved 02 22

0x58 Reserved 32

0x59 0x5a Reserved 01 ae

0x5b 0x5c Overload Current 5000 mA 13 88

0x5d 0x5e Over Voltage Margin 700 mV 02 bc

0x5f 0x60 Reserved 01 f4

0x61 0x62 Clear Fail Current 256 mA 01 00

0x63 0x64 Cell Over Voltage 4350 mV 10 fe

0x65 0x66 Cell Under Voltage 2300 mV 08 fc

0x67 0x68 Terminate Voltage 11300 mV 2c 24

0x69 0x6a Reserved 00 00

0x6b 0x6c Safety Over Voltage 20000 mV 3a 98

0x6d 0x6e Charge Suspend Temp High 60°C 02 58

0x6f 0x70 Charge Suspend Temp High Reset 55°C 02 26

0x71 0x72 Over Temperature Discharge 70°C 02 bc

0x73 0x74 Over Temperature Discharge Reset 60°C 02 58

0x75 0x76 Safety OverTemperature Charge 75°C 02 ee

0x77 0x78 Safety OverTemperature Discharge 75°C 02 ee

0x79 Charge Suspend Temp Low 0°C 00

0x7a Reserved ef

0x7b Current Deadband 3 mA 03

0x7c 0x7d Shutdown Voltage 8800 mV 22 60

0x7e 0x7f VOC75 15848 mV 3d e8

0x80 Reserved bf

0x81 Reserved 56

0x82 Reserved 40

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DATA FLASH ADDRESS DATA

NAME LI-ION EXAMPLE

HIGH BYTE LOW BYTE MSB LSB

0x83 0x84 VOC50 15240 mV 3b 88

0x85 Reserved 7f

0x86 Reserved 3d

0x87 Reserved 27

0x88 0x89 VOC25 15024 mV 3a b0

0x8a Reserved 3f

0x8b Reserved 24

0x8c Reserved 0e

0x8d Reserved 14

0x8e Voltage Average Time 1 s 01

0x8f Correction Current Limit 64 mA 40

0x90 0x91 Reserved 0b e1

0x92 0x93 Reserved 0b 68

0x94 Reserved 19

0x95 0x96 EMF/EDV0 3000 mV 0b b8

0x97 0x98 EDV C0 Factor/EDV1 3250 mV 0c b2

0x99 0x9a EDV R0 Factor/EDV2 3400 mV 0d 48

0x9b 0x9c EDV T0 Factor 0 00 00

0x9d 0x9e EDV R1 Factor 0 00 00

0x9f EDV TC Factor 0 00

0xa0 EDV C1 Factor 0 00

0xa1 Reserved 08

0xa2 Reserved 9b

0xa3 Reserved c7

0xa4 Reserved 64

0xa5 Reserved 14

0xa6 0xa7 Reserved 02 00

0xa8 0xa9 Reserved 01 00

0xaa Reserved 08

0xab Reserved 02

0xac Learning Low Temp 11.9°C 77

0xad Reserved 0a

0xae 0xaf Reserved 01 80

0xb0 0xb1 Reserved 01 00

0xb2 Reserved 08

0xb3 Reserved 18

0xb4 Reserved 14

0xb5 0xb6 TS Const 1 91 83

0xb7 0xb8 TS Const 2 51 70

0xb9 0xba TS Const 3 e2 8f

0xbb 0xbc TS Const 4 0f ac

0xbd 0xbe TS Const 5 00 00

0xbf 0xc0 Reserved 0f ac

0xc1 Reserved 02

0xc2 AFE State Control 00

0xc3 AFE Function Control 00

0xc4 AFE Cell Select 00

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DATA FLASH ADDRESS DATA

NAME LI-ION EXAMPLE

HIGH BYTE LOW BYTE MSB LSB

0xc5 AFE Overload 140 mV 12

0xc6 AFE Overload Delay 31 ms 0f

0xc7 AFE Short Circuit Charge 17

0xc8 AFE Short Circuit Discharge 17

0xc9 0xca AFE Vref* (1) 9750 mV 26 16

0xcb 0xcc Sense Resistor Gain* (1) 0.02 & 3b d0

0xcd 0xce CC Delta* (1) 0.0000323 mAh 92 0a

0xcf 0xd0 CC Delta* (1) 16 00

0xd1 Reserved fa

0xd2 0xd3 CC Offset* (1) 49701 c2 25

0xd4 DSC Offset* (1) 38 26

0xd5 ADC Offset* (1) 38 26

0xd6 Temperature Offset* (1) 0 00

0xd7 Board Offset* (1) 0 00

0xd8 0xd9 Reserved 00 40

0xda 0xdb Reserved 01 00

0xdc Reserved 05

0xdd 0xde Version 1.0 01 00

0xdf Reserved 00 32

0xe0 0xe1 Cell Over Voltage Reset 4150 mV 10 36

0xe2 0xe3 Cell Under Voltage Reset 3000 mV 0b b8

0xe4 0xe5 AFE Fail Limit 2 counts 00 02

0xe6 0xe7 Reserved ff ff

0xe8 0xe9 Cell Balance Thresh 3900 mV 0f 3c

0xea 0xeb Cell Balance Window 100 mV 00 64

0xec Cell Balance Min 40 mV 28

0xed Cell Balance Interval 20 s 14

0xee 0xef Cell Imbalance Threshold 01 f4

0xf0 0xf1 Balance Vcell Max 10 36

0xf2 0xf3 Balance Imax 00 9e

0xf4 0xf5 Reserved a5 5a

0xf6 0xf7 Reserved 7a 43

0xf8 0xf9 Reserved 20 83

0xfa Battery Low (LSB) 7.03 % 12

0xfb AFE Check Time 0 s 00

0xfc Sleep Current Thresh 2 mA 04

0xfd Sleep Current Multiplier 5 counts 05

0xfe Sleep Time 20 s 14

0xff 0x100 Manufacturer Info 1 00 00

0x101 0x102 Manufacturer Info 2 00 00

0x103 0x104 Manufacturer Info 3 00 00

0x105 0x106 Vmax Charge Voltage 4280 mv 10 b8

0x107 0x108 Voff Charge Voltage 4280 mv 10 b8

0x109 0x10a Von Charge Voltage 4200 mv 10 68

0x10b 0x10c Pulse Max On Time 60 s 01 e0

0x10d 0x10e Pulse Min Off Time 0.125 s 00 01

(1) Reserved locations must be set as shown. Locations marked with an * are typical calibration values that can be adjusted for maximum

accuracy. For these locations the table shows the appropriate default or initial setting.

Product Folder Link(s): bq2084-V133

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DATA FLASH ADDRESS DATA

NAME LI-ION EXAMPLE

HIGH BYTE LOW BYTE MSB LSB

0x10f 0x110 Max Charge Time 7200 s 1c 20

0x111 0x112 Precharge Detection Current 10 mA 00 0a

0x113 0x114 Charge Detection Current 100 mA 00 64

0x115 0x116 Discharge Detection Current -150 mA ff 6a

0x117 0x118 Reserved 10 68

0x119 0x11a Reserved 10 36

0x11b 0x11c Reserved 00

0x11d Permanent Fail Status 0 00

0x11e Permanent Fail Flag 0 00

0x11f Permanent Fail Config 0 00

0x120 Permanent Fail Input Time 0 00

0x121 0x122 Reserved 17 12

0x123 0x124 Reserved 26 73

0x125 0x126 FET Fail Charge Current 20 mA 00 20

0x127 0x128 FET Fail Discharge Current -20 mA ff ec

0x129 FET Fail Time 20 s 14

0x12a 0x12b Charge OC Threshold 4000 mA 0f a0

0x12c Charge OC Time 6 s 06

0x12d 0x12e Discharge OC Threshold 10970 mA 2a da

0x12f Discharge OC Time 10 s 00

0x130 Fault Reset Time 30 s 1e

0x131 0x132 VPACK Threshold 07 d0

0x133 Shutdown Timer 20 s 14

0x134 Cell Imbalance Time 20 s 14

0x135 0x136 Reserved

ADDITIONAL PROGRAMMING INFORMATION

ADDITIONAL DATA FLASH PROGRAMMING

The following sections describe the function of each data flash location and how the data is to be stored.

Fundamental Parameters

Sense Resistor Value

The 32-bit CC Delta (DF 0xcd-0xd0) corrects the coulomb counter for sense resistor variations. It represents the

gain factor for the coulomb counter. The 16-bit Sense Resistor Gain (DF 0xcb-0xcc) scales each integrating

converter conversion to mAh. The Current() related measurement Sense Resistor Gain is based on the

resistance of the series sense resistor. The following formula computes a nominal or starting value for Sense

Resistor Gain from the sense resistor value (in Ω).

Sense Resistor Gain = 306.25 ÷ Rs

RSNS Value (mΩ)Sense Resistor Gain

5 61250

10 30625

20 15312

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CC offset

CC offset (DF 0xd2-0xd3), contains the offset for the coulomb counter. It is automatically updated when the

pack has met the conditions for sleep, before it enters sleep mode.

DSC offset

DSC offset (DF 0xd4), contains the offset for the pack ground reference. It is automatically updated when the

pack has met the conditions for sleep, before it enters sleep mode.

ADC offset

ADC offset (DF 0xd5), contains the offset for the a/d converter. It is automatically updated when the pack has

met the conditions for sleep, before it enters sleep mode.

Digital Filter

The desired digital filter threshold, VDF (V), is set by the value stored in Digital Filter (DF 0x2c).

Digital Filter = VDF ÷ 290 nV

CELL AND PACK CHARACTERISTICS

Battery Pack Capacity and Voltage

Pack capacity in mAh units is stored in Design Capacity (DF 0x32-0x33). In mAh mode, the bq2084-V133 copies

Design Capacity to DesignCapacity(). In mWh mode, the bq2084-V133 multiplies Design Capacity by Design

Voltage (DF 0x04-0x05) to calculate DesignCapacity() scaled to 10 mWh. Design Voltage is stored in mV.

The initial value for Full Charge Capacity, in mAh, is stored in DF 0x36-0x37. Full Charge Capacity is modified

over the course of pack usage to reflect cell aging under the particular use conditions. The bq2084-V133 updates

Full Charge Capacity in mAh after a capacity learning cycle.

Remaining Time Alarm and Capacity Alarm

Remaining Time Alarm (DF 0x02-0x03) sets the alarm thresholds used in the SMBus command codes 0x01 and

0x02, respectively. Remaining Time Alarm is stored in minutes and Remaining Capacity Alarm in units of mAh or

10 mWh, depending on the BatteryMode() setting.

Cycle Count Initialization

Cycle Count (DF 0x0c-0x0d) stores the initial value for the CycleCount() function. It should be programmed to

0x0000.

Cycle Count Threshold

Cycle Count Threshold (DF 0x37-0x38) sets the number of mAh that must be removed from the battery to

increment CycleCount(). Cycle Count threshold is a 16-bit value stored in mAh.

Charge Efficiency

The bq2084-V133 applies the efficiency factor, EFF%, to all charge added to the battery. EFF% is encoded in

Charge Efficiency (DF 0x54) according to the following equation:

Charge Efficiency = (EFF% w 2.56-1)

PACK OPTIONS

Pack Configuration

Pack Configuration (DF 0x28) contains bit-programmable features.

b7 b6 b5 b4 b3 b2 b1 b0

DMODE LED1 LED0 HPE CPE SM CC1 CC0

Product Folder Link(s): bq2084-V133

bq2084-V133

SLUS640B –JUNE 2005–REVISED FEBRUARY 2010

www.ti.com

DMODE

The DMODE bit determines whether the LED outputs indicate AbsoluteStateOfCharge() or

RelativeStateOfCharge().

0 LEDs reflect AbsoluteStateOfCharge()

1 LEDs reflect RelativeStateOfCharge()

LED1–LED0

The LED bits set the number of LEDs for Remaining Capacity () indication.

0-0 Configures the bq2084-V133 for five LEDs

0-1 Configures the bq2084-V133 for three LEDs

1-0 Configures the bq2084-V133 for four LEDs

1-1 Configures the bq2084-V133 for five LEDs

HPE

The HPE bit enables/disables PEC transmissions to the smart battery host for master mode alarm messages.

0 No PEC byte on alarm warning to host

1 PEC byte on alarm warning to host

CPE

The CPE bit enables/disables PEC transmissions to the smart battery charger for master mode messages.

0 No PEC byte on broadcasts to charger

1 PEC byte on broadcasts to charger

The SM bit enables/disables master mode broadcasts by the bq2084-V133.

0 Broadcasts to host and charger enabled

1 Broadcasts to host and charger disabled

If the SM bit is set, modifications to bits in BatteryMode() do not re-enable broadcasts.

CC1–CC0

The CC bits configure the bq2084-V133 for the number of series cells in the battery pack.

1-1 Configures the bq2084-V133 for four series cells

1-0 Configures the bq2084-V133 for three series cells

0-1 Configures the bq2084-V133 for two series cells

Gauge Configuration

Gauge Configuration (DF 0x29) contains bit-programmable features:

b7 b6 b5 b4 b3 b2 b1 b0

0 CSYNC SC CEDV EDVV OVSEL VCOR OTVC

CSYNC

In usual operation of the bq2084-V133, the CSYNC bit is set so that the coulomb counter is adjusted when a

fast charge termination is detected. In some applications, especially those where an externally controlled

charger is used, it may be desirable not to adjust the coulomb counter. In these cases the CSYNC bit should be

cleared.

0 The bq2084-V133 does not alter RM at the time of a valid charge termination.

1 The bq2084-V133 updates RM with a programmed percentage of FCC at a valid charger termination.

Product Folder Link(s): bq2084-V133

bq2084-V133

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SLUS640B –JUNE 2005–REVISED FEBRUARY 2010

The SC bit enables learning cycle optimization for a Smart Charger or independent charge.

1 Learning cycle optimized for independent charger

0 Learning cycle optimized for Smart Charger

CEDV

The CEDV bit determines whether the bq2084-V133 implements automatic EDV compensation to calculate the

EDV0, EDV1, and EDV2 thresholds base on rate, temperature, and capacity. If the bit is cleared, the

bq2084-V133 uses the fixed values programmed in data flash for EDV0, EDV1, and EDV2. If the bit is set, the

bq2084-V133 calculates EDV0, EDV1, and EDV2.

0 EDV compensation disabled

1 EDV compensation enabled

EDVV

The EDVV bit selects whether EDV termination is to be done with regard to Voltage () or the lowest single-cell

voltage.

0 EDV conditions determined on the basis of the lowest single-cell voltage

1 EDV conditions determined on the basis of Voltage()

OVSEL

The OVSEL bit determines if Safety Over Voltage is based on Voltage () or highest cell voltages.

0 Safety overvoltage based on Voltage ()

1 Safety overvoltage based on highest cell voltage multiplied by the number of cells and then compared

to the safety voltage.

VCOR

The VCOR bit enables the midrange voltage correction algorithm. When it is set, the bq2084-V133 compares

the pack voltage to RM and may adjust RM according to the values programmed in VOC25, VOC50, and

VOC75.

0 Continuous midrange corrections disabled

1 Continuous midrange corrections enabled

OTVC

The OTVC bit programs the bq2084-V133 to perform a midrange voltage one time after a device reset

0 One-time midrange correction disabled

1 One-time midrange correction enabled

Miscellaneous Configuration

Misc Configuration (DF 0x2a, high, and 0x2b, low) contains additional bit programmable features.

Misc Configuration (DF 0x2a, high)

b15 b14 b13 b12 b11 b10 b9 b8

IT 0 AFEDET DS OT ECLED 1 VOD

The IT bit configures the bq2084-V133 to use its internal temperature sensor. The DF constants 0xb5-0xc0

need to match the required thermistor on internal temperature sensor. See the Data Flash Settings for Internal

or External Temperature Sensor Table.

0 bq2084-V133 requires an external thermistor.

1 bq2084-V133 uses its internal temperature sensor.

Product Folder Link(s): bq2084-V133

bq2084-V133

SLUS640B –JUNE 2005–REVISED FEBRUARY 2010

www.ti.com

AFEDET

The AFEDET bit programs the bq2084-V133 to look for errors with I2C communications and the AFE and

enables the detection of the AFE permanent failure if bit 3 of PF Config 0x11f is set.

0 Does not verify AFE communications.

1 Does verify AFE communications.

The DS bit programs the bq2084-V133 to enter sleep mode on SMBus inactivity.

0 bq2084-V133 enters sleep mode when the SMBus is low for 2 s.

1 bq2084-V133 does not enter sleep mode.

The OT bit programs the bq2084-V133 to turn off the discharge FET when the bq2084-V133 detects an

overtemperature condition. Charge FET is always turned off in overtemperature conditions.

0 bq2084-V133 does not turn off the discharge FET on overtemperature.

1 bq2084-V133 turns off the discharge FET on overtemperature.

ECLED

The ECLED bit programs the LED activity during charging (DSG bit = 0).

0 The LEDs are not enabled during charging.

1 The LEDs are enabled during charging.

VOD

The VOD bit enables a 1-s time delay in the setting of the CVOV and CVUV bits in PackStatus.

0 No delay

1 1-s delay

Misc Configuration (DF 0x2b, low)

b7 b6 b5 b4 b3 b2 b1 b0

LEDRCA PFET1 PFET0 NR CHGFET 0 0 0

LEDRCA

The LEDRCA bit programs the LED to blink when there is a RemainingCapacityAlarm.

0 The LEDs blink when there is a RemainingCapacityAlarm.

1 The LEDs are off when there is a RemainingCapacityAlarm.

PFET1, PFET0

The PFETx bits define the precharge FET operation. See the bq29312 data sheet for more detail.

0,0 The bq29312 ZVCHG FET is turned on for precharge. Assumes charger has precharge function.

0,1 The charge FET is turned on for precharge. Assumes charger has precharge function.

1,0 The bq29312 OD FET is turned on for precharge. Assumes charger does not have precharge function.

1,1 Not defined, unpredictable operation

Product Folder Link(s): bq2084-V133

bq2084-V133

www.ti.com

SLUS640B –JUNE 2005–REVISED FEBRUARY 2010

The NR bit defines whether the bq2084-V133 is to be used with a nonremovable system battery. If set to

indicate a nonremovable system battery there are additional clear conditions for a battery failure due to

overcharge, overcurrent, and overload. The additional conditions besides battery removal (defined as the loss

system present pin going high) are either detection of an opposite current of that that caused the failure or

when AverageCurrent() is less than Clear Fail Current DF 0x61, 0x62 for a time defined by Fault Reset Time

DF 0x130. Also, for a nonremovable battery the charge FET is left on for discharge current failures and the

discharge FET is left on for charge current failures.

0 Removable battery, battery fail conditions cleared by battery removal only.

1 Nonremovable system battery.

CHGFET

The CHGFET bit programs the charge FET to remain on even after a charge terminate condition.

0 The charge FET is turned off after a charge termination condition.

1 The charge FET is turned on after a charge termination condition.

Constants and String Data

Specification Information

Specification Information (DF 0x06-0x07) stores the default value for the SpecificationInfo() function. It is stored

in data flash in the same format as the data returned by the SpecificationInfo().

Manufacture Date

Manufacture Date (DF 0x08-0x09) stores the default value for the ManufactureDate() function. It is stored in data

flash in the same format as the data returned by the ManufactureDate().

Serial Number

Serial Number (DF 0x0a-0x0b) stores the default value for the SerialNumber() function. It is stored in data flash

in the same format as the data returned by the SerialNumber().

Manufacturer Name Data

Manufacturer Name Length (DF 0x0e) stores the length of the desired string that is returned by the

ManufacturerName() function. Locations DF 0x0f-0x19 store the characters for ManufacturerName() in ASCII

code.

Device Name Data

Device Name Length (DF 0x1a) stores the length of the desired string that is returned by the DeviceName()

function. Locations DF 0x1b-0x21 store the characters for DeviceName() in ASCII code.

Device Chemistry Data

Device Chemistry Length (DF 0x22) stores the length of the desired string that is returned by the

DeviceChemistry() function. Locations DF 0x23-0x26 store the characters for DeviceChemistry() in ASCII code.

Manufactuters Data Length

Manufacturers Data Length (DF 0x27) stores the length of the desired number of bytes that is returned by the

ManufacturersData() function. It should be set to 9.

Temperature Limits

The limits described below are extensions to those limits detailed in the safety and charging sections of this data

sheet.

Product Folder Link(s): bq2084-V133

bq2084-V133

SLUS640B –JUNE 2005–REVISED FEBRUARY 2010

www.ti.com

Charge Suspend Temp Low

Charge Suspend Temp Low (DF 0x79) sets the lowest temperature, in degrees C/10, at which normal operation

is allowed. If the temperature falls below this limit, the pack goes into a temporary failure state, the charge FET is

turned off, and the MAC status is set to system present. It is cleared when the pack warms, or the pack is

removed.

Charge Inhibit Temp Low

Charge Inhibit Temp Low (DF 0x46) inhibits charging by setting ChargingCurrent() and ChargingVoltage() to 0

and turn off the CHG FET. It is programmed in degrees C ÷ 10, and the range of -12.8°C to 12.7°C.

Charge Inhibit Temp High

Charge Inhibit Temp High (DF 0x47-0x48) inhibits charging by setting ChargingCurrent() and ChargingVoltage()

to 0

Charge Suspend Temp High

Charge Suspend Temp High (DF 0x6d-0x6e) sets the highest temperature, in degrees C ÷ 10, at which charging

will be allowed to continue. If this temperature is exceeded during charging, the pack goes into a temporary

failure state, and the MAC status is set to system present. It is cleared when the pack cools below

OverTemperature Charge Reset, or ac adapter is removed, or the pack is removed. Charging can only resume

when the temperature returns to within the charge start temperature limits.

Charge Suspend Temp High Reset

Charge Suspend Temp High Reset (DF 0x6f-0x70) sets the temperature, in degrees C/10, at which the pack

recovers from Charge Suspend Temp High fault.

Over Temperature Discharge

Over Temperature Discharge (DF 0x71-0x72) sets the highest temperature, in degrees C/10, at which

discharging will be allowed. If the pack exceeds this temperature, charge and discharge FETs are turned off, and

MAC status is set to system present. The pack returns to normal operation when the temperature falls below

Over Temperature Discharge Reset, or if the pack is removed.

Over Temperature Discharge Reset

Over Temperature Discharge Reset (DF 0x73-0x74) sets the temperature, in degrees C/10, at which the pack

will recover from Over Temperature Discharge Over temperature will also reset when the pack is removed from

the system if not in the non-removable mode.

Failure Detection Thresholds

Safety OverTemperature Charge

Safety OverTemperature Charge (DF 0x75-0x76) sets the temperature, in degrees C/10, above which, during

charging, the pack enters permanent failure, if the XSOTC bit in Permanent Failure Configuration is set.

Safety OverTemperature Discharge

Safety OverTemperature Discharge (DF 0x77-0x78) sets the temperature, in degrees C/10, above which, during

discharging, the pack enters permanent failure, if the XSOTD bit in Permanent Failure Configuration is set.

Charge Detection Current

Charge Detection Current (DF 0x113-0x114) sets the threshold in milliamperes for detecting charge current. This

is a signed value and is positive. This threshold is used for detecting cross-conduction, and ensuring that charge

termination is not improperly detected due to loss of charging current.

Product Folder Link(s): bq2084-V133

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www.ti.com

SLUS640B –JUNE 2005–REVISED FEBRUARY 2010

Discharge Detection Current

Discharge Detection Current (DF 0x115-0x116) sets the threshold in milliamperes for detecting discharge

current. This is a signed value and is negative. This threshold is used for detecting cross-conduction and

determining that the charge FET should be turned on during discharge to reduce IR losses.

FET Fail Charge Current

FET Fail Charge Current (DF 0x125-0x126) sets the threshold in milliamperes for detecting current in a charge

FET which is turned off. This is a signed value and is positive.

FET Fail Discharge Current

FET Fail Discharge Current (DF 0x127-0x128) sets the threshold in milliamperes for detecting current in a

discharge FET which is turned off. This is a signed value and is negative.

FET Fail Time

FET Fail Time (DF 0x129) sets the time in seconds that current must be detected in a FET which is turned off, in

order to determine that the FET has failed.

Terminate Voltage

Terminate Voltage (DF 0x67-0x68) sets the threshold below which the Terminate Discharge Alarm bit is set. The

alarm is cleared when the voltage rises above this threshold, if the CVUV bit in Pack Status is not set.

Offsets and Limits

Temperature offset

Temperature offset (DF 0xd6) contains a signed offset for the pack's temperature measurements, in degrees

C/10. It is set at board test during pack calibration.

Board offset

Board offset (DF 0xd7), contains a signed offset for the pack's coulomb counter measurements. If used, it is set

at board design time.

Current Deadband

Current Deadband (DF 0x7b), sets the threshold in mA below which a current measurement is not detected.

Shutdown Voltage

Shutdown Voltage (DF 0x7c-0x7d) sets the pack voltage below which the pack's electronics, including the

bq2084-V133, is shut down to conserve power. All FETs are turned off by the AFE.

APPLICATION INFORMATION

Figure 7 shows a typical bq2084-V133-based battery pack application. The circuit consists of the bq29312 AFE

IC, bq29400 second-level protection IC, LED, temperature measurement network, data flash connections, serial

port, and the sense resistor. The data flash stores basic battery pack configuration information and measurement

calibration values. The data flash must be programmed properly for bq2084-V133 operation.

Product Folder Link(s): bq2084-V133

CELL

TOUT

XALERT

SDATA

WDI

SCLK

PACK 18

REG

SR1 12GND

GND

SR2

bq29312

R3 100

R4 1 k

0.1µF C3

R5 1 k

1 kR6

R7 1 k

0.1µF

0.1µFC7

VC1

VC2

VC3

GND

OUT

VDD

VC4

bq29400 BAV99

D2 2N7002

JP1

100 k

R43

2N7002

Q2 3

C12

0.1µF

BAT54LT1

BSS84

BAV99

R11

100

R10

100

0.1µF0.1µF 0.1µF 0.1µF 0.1µF

C2 C8 C9 C10 C11

1µF 50 V

BAT4P

BAT3P

BAT2P

BAT1P

BATIN

VCC

100 k

R45

100 k

R12

BAT

SLEEP

VC1

VC2

VC3

VC4

VC5

PMS

DSG ZVCHG CHG

R15

100

R16

100 0.1µF

C16 0.1µF

C18

0.1µF

C19 1

R1 .020 75 PPM

R20 100

C20

0.1µF

8.45 k

R19

4.7µF

C17

VCC

R13

5 k

R14

5 k R17

5 k BAT54LT1

VCC

R44

100 k

R42 100 k

C21

0.47µF

R21

61.9 k

RT1

10 k

C13

0.1µFC14

0.1µF

Si4435DY

2 1

8 65

4 4

8765

23 1

Si4435DY

R18

1 M R22

300

1 W

R23

1 M

C22

0.047 µFSi4435DY

R27

C24 0.47µF

C25 68 PF

VCC

R28

C27 0.47µF

C28 68 PF

26 9 13 17

VSSA

VSSD

VDDD VDDA

8 31

VSSD

PFIN

SAFE

SCLK

SDATA

EVENT

CLKOUT

VIN

PRES

SR1

SR2

MRST RBI NC DISP

VSSAVSSA

VSSA/XCK1

ROSC/XCK2

SMBC

SMBD

FLT

LED5

LED4

LED3

LED2

LED1

bq2084

R24 5 k

R25 100

C26

0.1µF3

SW1

VCC

100 k

R29

R34 470

R33 470

R32 470

R31 470

R30 470

VCC

GREEN

R35

100 k

R37

100

R38

100

R36 61.9 k

C30 2200 pF

C29 150 pF

R41 100

R40 100

D11

AZ23C5V6

SMBC

SMBD X8

D10

AZ23C5V6

R39 100

Sys Pres X7

PACK− X10

1 M

8 65

2 13

R46

1 M1 M R47

1 M

0.47 µF

bq2084-V133

SLUS640B –JUNE 2005–REVISED FEBRUARY 2010

www.ti.com

Figure 7. bq2084-V133 Based Battery Pack Schematic

Product Folder Link(s): bq2084-V133

bq2084-V133

www.ti.com

SLUS640B –JUNE 2005–REVISED FEBRUARY 2010

REVISION HISTORY

Changes from Revision A (June 2005) to Revision B Page

• Changed Table 10 CVOV entry From: VCELL(ANY) =Cell Over Voltage To: VCELL(ANY) ≥Cell Over Voltage .................. 20

• Changed Table 10 CVUV entry From: VCELL(ANY) =Cell Under Voltage To: VCELL(ANY) ≤Cell Under Voltage .............. 20

• Changed Table 10 Note 2 From: On if there is a discharge current ≥150mA To: On if there is a discharge current ≥

Discharge Detection Current .............................................................................................................................................. 20

• Changed Table 10 Note 3 From: On if there is a charge current ≥Charge Detection Current ≥50mA To: On if there

is a charge current ≥Charge Detection Current ≥Charge Detection Current ................................................................... 20

• Changed 1st Level Cell Voltage Thresholds section. .......................................................................................................... 20

• Changed Overcurrent Thresholds section .......................................................................................................................... 20

Product Folder Link(s): bq2084-V133

PACKAGING INFORMATION

Orderable Device Status (1) Package

Type Package

Drawing Pins Package

Qty Eco Plan (2) Lead/Ball Finish MSL Peak Temp (3)

BQ2084DBT-V133 NRND TSSOP DBT 38 50 Green (RoHS &

no Sb/Br) Call TI Level-2-260C-1 YEAR

BQ2084DBT-V133G4 NRND TSSOP DBT 38 50 Green (RoHS &

no Sb/Br) Call TI Level-2-260C-1 YEAR

BQ2084DBTR-V133 NRND TSSOP DBT 38 2000 Green (RoHS &

no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR

BQ2084DBTR-V133G4 NRND TSSOP DBT 38 2000 Green (RoHS &

no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR

(1) The marketing status values are defined as follows:

ACTIVE: Product device recommended for new designs.

LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.

NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in

a new design.

PREVIEW: Device has been announced but is not in production. Samples may or may not be available.

OBSOLETE: TI has discontinued the production of the device.

(2) Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check

http://www.ti.com/productcontent for the latest availability information and additional product content details.

TBD: The Pb-Free/Green conversion plan has not been defined.

Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements

for all 6 substances, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered

at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes.

Pb-Free (RoHS Exempt): This component has a RoHS exemption for either 1) lead-based flip-chip solder bumps used between the die and

package, or 2) lead-based die adhesive used between the die and leadframe. The component is otherwise considered Pb-Free (RoHS

compatible) as defined above.

Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame

retardants (Br or Sb do not exceed 0.1% by weight in homogeneous material)

(3) MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder

temperature.

Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is

provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the

accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and continues to take

reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on

incoming materials and chemicals. TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited

information may not be available for release.

In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI

to Customer on an annual basis.

PACKAGE OPTION ADDENDUM

www.ti.com 16-Nov-2009

Addendum-Page 1

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