1
FEATURES
APPLICATIONS
DESCRIPTION
AC Adapter
VDC
GND
1 Fm
1
27
5
4
6
8
bq24314A
bq24080
ChargerIC
SYSTEM
IN OUT
VBAT
FAULT
CE
VSS
ILIM
1 Fm
APPLICATIONSCHEMATIC
bq24314A
SLUS811 – MARCH 2008www.ti.com
OVERVOLTAGE AND OVERCURRENT PROTECTION IC ANDLi+ CHARGER FRONT-END PROTECTION IC
•Available in Space-Saving Small 8 Lead 2 ×2SON23
•Provides Protection for Three Variables:– Input Overvoltage, with Rapid Response in< 1 µs
•Mobile Phones and Smart Phones– User-Programmable Overcurrent with
•PDAsCurrent Limiting
•MP3 Players– Battery Overvoltage
•Low-Power Handheld Devices•30V Maximum Input Voltage
•Bluetooth™ Headsets•Supports up to 1.5A Input Current•Robust Against False Triggering Due toCurrent Transients•Thermal Shutdown•Enable Input•Status Indication – Fault Condition
The bq24314A is a highly integrated circuit designed to provide protection to Li-ion batteries from failures of thecharging circuit. The IC continuously monitors the input voltage, the input current, and the battery voltage. Incase of an input overvoltage condition, the IC immediately removes power from the charging circuit by turning offan internal switch. In the case of an overcurrent condition, it limits the system current at the threshold value, andif the overcurrent persists, switches the pass element OFF after a blanking period. Additionally, the IC alsomonitors its own die temperature and switches off if it exceeds 140 °C. The input overcurrent threshold isuser-programmable.
The IC can be controlled by a processor and also provides status information about fault conditions to the host.
1
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications ofTexas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
2PowerPAD is a trademark of Texas Instruments.3Bluetooth is a trademark of Bluetooth SIG, Inc.
PRODUCTION DATA information is current as of publication date.
Copyright © 2008, Texas Instruments IncorporatedProducts conform to specifications per the terms of the TexasInstruments standard warranty. Production processing does notnecessarily include testing of all parameters.
www.ti.com
PACKAGE DISSIPATION RATINGS
ABSOLUTE MAXIMUM RATINGS
(1)
RECOMMENDED OPERATING CONDITIONS
bq24314A
SLUS811 – MARCH 2008
These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foamduring storage or handling to prevent electrostatic damage to the MOS gates.
ORDERING INFORMATION
(1)
DEVICE
(2)
OVP THRESHOLD PACKAGE MARKING
bq24314ADSG 5.85 V 2mm x 2mm SON CGG
(1) For the most current package and ordering information, see the Package Option Addendum at the endof this document, or see the TI website at www.ti.com.(2) To order a 3000 pcs reel add R to the part number, or to order a 250 pcs reel add T to the partnumber.
PART NO. PACKAGE R
θJC
R
θJA
bq24314ADSG 2 ×2 SON 5 °C/W 75 °C/W
over operating free-air temperature range (unless otherwise noted)
PARAMETER PIN VALUE UNIT
IN (with respect to VSS) – 0.3 to 30V
I
Input voltage OUT (with respect to VSS) – 0.3 to 12 VILIM, FAULT, CE, VBAT (with respect to VSS) – 0.3 to 7I
I
Input current IN 2 AI
O
Output current OUT 2 AOutput sink current FAULT 15 mAAll (Human Body Model per JESD22-A114-E) 2000 VAll (Machine Model per JESD22-A115-E) 200 VESD Withstand Voltage
All (Charge Device Model per JESD22-C101-C) 500 VIN(IEC 61000-4-2) (with IN bypassed to the VSS 15 (Air Discharge) kVwith a 1- µF low-ESR ceramic capacitor) 8 (Contact)T
J
Junction temperature – 40 to 150 °CT
stg
Storage temperature – 65 to 150 °C
(1) Stresses beyond those listed under absolute maximum ratings may cause permanent damage to the device. These are stress ratingsonly, and functional operation of the device at these or any other conditions beyond those indicated under recommended operatingconditions is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability. All voltagevalues are with respect to the network ground terminal unless otherwise noted.
over operating free-air temperature range (unless otherwise noted)
MIN MAX UNIT
V
IN
Input voltage range 3 30 VI
IN
Input current, IN pin 1.5 AI
OUT
Output current, OUT pin 1.5 AR
ILIM
OCP Programming resistor 15 90 k Ω
T
J
Junction temperature – 40 125 °C
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ELECTRICAL CHARACTERISTICS
bq24314A
SLUS811 – MARCH 2008
over junction temperature range – 40 °C to 125 °C and recommended supply voltage (unless otherwise noted)
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
IN
Undervoltage lock-out, input powerUVLO CE = Low, V
IN
increasing from 0V to 3V 2.6 2.7 2.8 Vdetected thresholdV
hys(UVLO)
Hysteresis on UVLO CE = Low, V
IN
decreasing from 3V to 0V 200 260 300 mVDeglitch time, input power detected CE = Low. Time measured from V
IN
0V →5V 1 µsT
DGL(PGOOD)
8 msstatus rise-time, to output turning ONCE = Low, No load on OUT pin,I
DD
Operating current 400 600 µAV
IN
= 5V, R
ILIM
= 25k Ω
I
STDBY
Standby current CE = High, V
IN
= 5.0V 65 95 µA
INPUT TO OUTPUT CHARACTERISTICS
VDO Drop-out voltage IN to OUT CE = Low, V
IN
= 5V, I
OUT
= 1A 170 280 mV
INPUT OVERVOLTAGE PROTECTION
V
OVP
Input overvoltage protection threshold CE = Low, V
IN
increasing from 5V to 7.5V 5.71 5.85 6.00 Vt
PD(OVP)
Input OV propagation delay
(1)
CE = Low 200 nsV
hys(OVP)
Hysteresis on OVP CE = Low, V
IN
decreasing from 7.5V to 5V 20 60 110 mVRecovery time from input overvoltage CE = Low, Time measured fromt
ON(OVP)
8 mscondition V
IN
7.5V →5V, 1 µs fall-time
INPUT OVERCURRENT PROTECTION
Input overcurrent protection thresholdI
OCP
300 1500 mArange
CE = Low, R
ILIM
= 24.9k Ω,I
OCP
Input overcurrent protection threshold 900 1000 1100 mA3 V ≤V
IN
< V
OVP
-V
hys(OVP)
K
ILIM
Programmable current limit factor 25 A Ω
Blanking time, input overcurrentt
BLANK(OCP)
176 µsdetected
Recovery time from input overcurrentt
REC(OCP)
64 mscondition
BATTERY OVERVOLTAGE PROTECTION
Battery overvoltage protectionBV
OVP
CE = Low, V
IN
> 4.4V 4.30 4.35 4.4 VthresholdV
hys(Bovp)
Hysteresis on BV
OVP
CE = Low, V
IN
> 4.4V 200 275 320 mVI
VBAT
Input bias current on VBAT pin V
BAT
= 4.4V, T
J
= 25 °C 10 nADeglitch time, battery overvoltage CE = Low, V
IN
> 4.4V. Time measured from V
VBATT
DGL(Bovp)
176 µsdetected rising from 4.1V to 4.4V to FAULT going low.
THERMAL PROTECTION
T
J(OFF)
Thermal shutdown temperature 140 150 °CT
J(OFF-HYS)
Thermal shutdown hysteresis 20 °C
LOGIC LEVELS ON CE
V
IL
Low-level input voltage 0 0.4 VV
IH
High-level input voltage 1.4 VI
IL
Low-level input current V
CE
= 0V 1 µAI
IH
High-level input current V
CE
= 1.8V 15 µA
LOGIC LEVELS ON FAULT
V
OL
Output low voltage I
SINK
= 5mA 0.2 VI
HI-Z
Leakage current, FAULT pin HI-Z V
FAULT
= 5V 10 µA
(1) Not tested in production. Specified by design.
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OUT
FAULT
VSS
THERMAL
SHUTDOW
CE
COUNTERS,
CONTROL,
AND STATUS
ILIM
VBAT
VIN
ILIMREF
ILIMREF - Δ tBLANK(OCP)
tDGL(PGOOD)
ISNS
ISNS
OFF
tDGL(BOVP)
ChargePump,
Bandgap,
BiasGen
Q1
VBG
VBG
VIN VBG
OVP
UVLO
VBG
Currentlimiting
loop
OCP comparator
IN
bq24314A
SLUS811 – MARCH 2008
Figure 1. Simplified Block Diagram
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TERMINAL FUNCTIONS
NC
VSS
FAULT
IN OUT
CE
1
2
36
8
7
45
VBAT
ILIM
bq24314A
bq24314A
SLUS811 – MARCH 2008
TERMINAL
I/O DESCRIPTIONNAME DSG
IN 1 I Input power, connect to external DC supply. Connect external 1 µF ceramic capacitor (minimum) to V
SS
.OUT 8 O Output terminal to the charging system. Connect external 1 µF ceramic capacitor (minimum) to V
SS
.VBAT 6 I Battery voltage sense input. Connect to pack positive terminal through a resistor.ILIM 7 I/O Input overcurrent threshold programming. Connect a resistor to VSS to set the overcurrent threshold.CE 5 I Chip enable input. Active low. When CE = High, the input FET is off. Internally pulled down.Open-drain output, device status. FAULT = Low indicates that the input FET Q1 has been turned off dueFAULT 4 O
to input overvoltage, input overcurrent, battery overvoltage, or thermal shutdown.VSS 2 – Ground terminalThese pins may have internal circuits used for test purposes. Do not make any external connections atNC 3
these pins for normal operation.There is an internal electrical connection between the exposed thermal pad and the V
SS
pin of thedevice. The thermal pad must be connected to the same potential as the V
SS
pin on the printed circuitThermal PAD –
board. Do not use the thermal pad as the primary ground input for the device. The VSS pin must beconnected to ground at all times.
DSG Package
(Top View)
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TYPICAL OPERATING PERFORMANCE
VIN
VOUT
IOUT
VIN
VOUT
FAULT
VIN
VOUT
MaxV =5.92V
OUT
FAULT
VIN
VOUT
MaxV =5.84V
OUT
FAULT
bq24314A
SLUS811 – MARCH 2008
Test conditions (unless otherwise noted) for typical operating performance: V
IN
= 5 V, C
IN
= 1 µF, C
OUT
= 1 µF,R
ILIM
= 25 k Ω, R
BAT
= 100 k Ω, T
A
= 25 °C, V
PU
= 3.3V (see Figure 20 for the Typical Application Circuit)
Figure 2. Normal Power-On Showing Soft-Start, Figure 3. OVP at Power-On, V
IN
= 0V to 9V, t
r
= 50 µsR
OUT
= 6.6 Ω
Figure 4. OVP Response for Input Step, V
IN
= 5V to 12V, t
r
Figure 5. OVP Response for Input Step, V
IN
= 5V to 12V, t
r= 1 µs = 20 µs
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VIN
VOUT
IOUT
FAULT
VIN
VOUT
IOUT
FAULT
VIN
VOUT
IOUT
FAULT
VIN
VOUT
IOUT
FAULT
VOUT
VVBAT
FAULT
VVBAT
VOUT
FAULT
Begin
soft-stop
t
=220 s
DGL(BAT-OVP)
m
bq24314A
SLUS811 – MARCH 2008
TYPICAL OPERATING PERFORMANCE (continued)
Figure 6. Recovery from OVP, V
IN
= 7.5V to 5V, t
f
= 400 µs Figure 7. OCP, Powering Up into a Short Circuit on OUTPin, OCP Counter Counts to 15 Before Switching OFF theDevice
Figure 8. OCP, Zoom-in on the First Cycle of Figure 7 Figure 9. OCP, R
OUT
Switches from 6.6 Ωto 3.3 Ω, ShowsCurrent Limiting and Soft-Stop
Figure 10. BAT-OVP, V
VBAT
Steps from 4.2V to 4.4V, Figure 11. BAT-OVP, V
VBAT
Cycles Between 4.1V and 4.4V,Shows t
DGL(BAT-OVP)
and Soft-Stop Shows BAT-OVP Counter
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2.4
2.45
2.5
2.55
2.6
2.65
2.7
2.75
-50 -30 -10 10 30 50 70 90 110 130
V Increasing
IN
V Decreasing
IN
Temperature- C°
V ,V -V
UVLO HYS-UVLO
0
200
400
600
800
1000
1200
1400
1600
0 10 20 30 40 50 60 70 80 90 100
I -mA
OCP
R -k
ILIM W
5.78
5.8
5.82
5.84
5.86
5.88
-50 -30 -10 10 30 50 70 90 110 130
V Increasing
IN
V Decreasing
IN
Temperature- C°
V ,V -V
OVP HYS-OVP
4.05
4.1
4.15
4.2
4.25
4.3
4.35
4.4
-50 -30 -10 10 30 50 70 90 110 130
BV (V Increasing)
OVP VBAT
Bat-OVP Recovery(V Decreasing)
VBAT
BV -V
OVP
Temperature- C°
975
976
977
978
979
980
981
982
983
984
985
-50 -30 -10 10 30 50 70 90 110 130
I -mA
OCP
Temperature- C°
bq24314A
SLUS811 – MARCH 2008
TYPICAL OPERATING PERFORMANCE (continued)
UNDERVOLTAGE LOCKOUT DROPOUT VOLTAGE (IN to OUT)vs vsFREE-AIR TEMPERATURE FREE-AIR TEMPERATURE
Figure 12. Figure 13.
OVERVOLTAGE THRESHOLD PROTECTION INPUT OVERCURRENT PROTECTIONvs vsFREE-AIR TEMPERATURE ILIM RESISTANCE
Figure 14. Figure 15.
INPUT OVERCURRENT PROTECTION BATTERY OVERVOLTAGE PROTECTIONvs vsFREE-AIR TEMPERATURE FREE-AIR TEMPERATURE
Figure 16. Figure 17.
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0
100
200
300
400
500
600
700
800
900
0 5 10 15 20 25 30 35
I ( =Low)
DD CE
I ( =High)
STDBY CE
I ,I - A
DD STDBY m
V -V
IN
0
0.5
1
1.5
2
2.5
-50 -30 -10 10 30 50 70 90 110 130
Temperature- C°
I-nA
VBAT
bq24314A
SLUS811 – MARCH 2008
TYPICAL OPERATING PERFORMANCE (continued)
LEAKAGE CURRENT (VBAT Pin) SUPPLY CURRENTvs vsFREE-AIR TEMPERATURE INPUT VOLTAGE
Figure 18. Figure 19.
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TYPICAL APPLICATION CIRCUIT
AC Adapter
VDC
GND
CIN
1
72
5
4
6
8
bq24314A
bq24080
ChargerIC
SYSTEM
IN OUT
VBAT
FAULT
CE
VSS
ILIM
COUT
COUT
RBAT
RCE
Host
Controller
RFAULT
VPU
RPU
1 Fm1 Fm
100kW
47kW
47kW
47kW
RILM
24.9kW
DETAILED FUNCTIONAL DESCRIPTION
POWER DOWN
POWER-ON RESET
bq24314A
SLUS811 – MARCH 2008
V
OVP
= 6.8V, I
OCP
= 1000mA, BV
OVP
= 4.35V (Terminal numbers shown are for the 2 ×2 DSG package)
Figure 20.
The bq24314A is a highly integrated circuit designed to provide protection to Li-ion batteries from failures of thecharging circuit. The IC continuously monitors the input voltage, the input current and the battery voltage. In caseof an input overvoltage condition, the IC immediately removes power from the charging circuit by turning off aninternal switch. In the case of an overcurrent condition, it limits the system current at the threshold value, and ifthe overcurrent persists, switches the pass element OFF after a blanking period. If the battery voltage rises to anunsafe level, the IC disconnects power from the charging circuit until the battery voltage returns to an acceptablevalue. Additionally, the IC also monitors its own die temperature and switches off if it exceeds 140 °C. The inputovercurrent threshold is user-programmable. The IC can be controlled by a processor, and also provides statusinformation about fault conditions to the host.
The device remains in power down mode when the input voltage at the IN pin is below the undervoltagethreshold UVLO. The FET Q1 connected between IN and OUT pins is off, and the status output, FAULT, is set toHi-Z.
The device resets when the input voltage at the IN pin exceeds the UVLO threshold. All internal counters andother circuit blocks are reset. The IC then waits for duration t
DGL(PGOOD)
for the input voltage to stabilize. If, aftert
DGL(PGOOD)
, the input voltage and battery voltage are safe, FET Q1 is turned ON. The IC has a soft-start featureto control the inrush current. The soft-start minimizes the ringing at the input (the ringing occurs because theparasitic inductance of the adapter cable and the input bypass capacitor form a resonant circuit). Figure 2 showsthe power-up behavior of the device. Because of the deglitch time at power-on, if the input voltage rises rapidly tobeyond the OVP threshold, the device will not switch on at all, instead it will go into protection mode and indicatea fault on the FAULT pin, as shown in Figure 3 .
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OPERATION
Input Overvoltage Protection
Input Overcurrent Protection
Battery Overvoltage Protection
Thermal Protection
Enable Function
Fault Indication
bq24314A
SLUS811 – MARCH 2008
The device continuously monitors the input voltage, the input current, and the battery voltage as described indetail in the following sections.
If the input voltage rises above V
OVP
, the internal FET Q1 is turned off, removing power from the circuit. Asshown in Figure 4 to Figure 5 , the response is very rapid, with the FET turning off in less than a microsecond.The FAULT pin is driven low. When the input voltage returns below V
OVP
– V
hys(OVP)
(but is still above UVLO), theFET Q1 is turned on again after a deglitch time of t
ON(OVP)
to ensure that the input supply has stabilized. Figure 6shows the recovery from input OVP.
The overcurrent threshold is programmed by a resistor R
ILIM
connected from the ILIM pin to VSS. Figure 15shows the OCP threshold as a function of R
ILIM
, and may be approximated by the following equation:I
OCP
= 25 ÷R
ILIM
(current in A, resistance in k Ω), where R
ILIM
must be between 15 k Ωand 90 k Ω.
If the load current tries to exceed the I
OCP
threshold, the device limits the current for a blanking duration oft
BLANK(OCP)
. If the load current returns to less than I
OCP
before t
BLANK(OCP)
times out, the device continues tooperate. However, if the overcurrent situation persists for t
BLANK(OCP)
, the FET Q1 is turned off for a duration oft
REC(OCP)
, and the FAULT pin is driven low. The FET is then turned on again after t
REC(OCP)
and the current ismonitored all over again. Each time an OCP fault occurs, an internal counter is incremented. If 15 OCP faultsoccur in one charge cycle, the FET is turned off permanently. The counter is cleared either by removing andre-applying input power, or by disabling and re-enabling the device with the CE pin. Figure 7 to Figure 9 showwhat happens in an overcurrent fault.
To prevent the input voltage from spiking up due to the inductance of the input cable, Q1 is turned off slowly,resulting in a “ soft-stop ” , as shown in Figure 9 .
The battery overvoltage threshold BV
OVP
is internally set to 4.35V. If the battery voltage exceeds the BV
OVPthreshold, the FET Q1 is turned off, and the FAULT pin is driven low. The FET is turned back on once the batteryvoltage drops to BV
OVP
– V
hys(Bovp)
(see Figure 10 and Figure 11 ). Each time a battery overvoltage fault occurs,an internal counter is incremented. If 15 such faults occur in one charge cycle, the FET is turned off permanently.The counter is cleared either by removing and re-applying input power, or by disabling and re-enabling thedevice with the CE pin. In the case of a battery overvoltage fault, Q1 is switched OFF gradually (see Figure 10 ).
If the junction temperature of the device exceeds T
J(OFF)
, the FET Q1 is turned off, and the FAULT pin is drivenlow. The FET is turned back on when the junction temperature falls below T
J(OFF)
– T
J(OFF-HYS)
.
The IC has an enable pin which can be used to enable or disable the device. When the CE pin is driven high, theinternal FET is turned off. When the CE pin is low, the FET is turned on if other conditions are safe. The OCPcounter and the Bat-OVP counter are both reset when the device is disabled and re-enabled. The CE pin has aninternal pulldown resistor and can be left floating. Note that the FAULT pin functionality is also disabled when theCE pin is high.
The FAULT pin is an active-low open-drain output. It is in a high-impedance state when operating conditions aresafe, or when the device is disabled by setting CE high. With CE low, the FAULT pin goes low whenever any ofthese events occurs:•Input overvoltage
•Input overcurrent
•Battery overvoltage•IC Overtemperature
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V(IN)>V(UVLO)? No
CE=Low?
No
V(IN)<V(OVP)?
Yes
No
TurnoffFET
FAULT =Low
I<IOCP ?
Yes
No
WaittREC(OCP)
VBAT <BATOVP ?
Yes
No
TurnonFET
FAULT =HiZ
TurnoffFET
FAULT =Low
IncrOCP counter count<15 ?
CE=Hi?
No
No
GotoReset
Yes
TurnoffFET
FAULT =Low
IncrBAT counter count<15 ?
CE=Hi? GotoReset
Yes
No
No
Yes
Yes
No
TurnoffFET
FAULT =Low
PowerDown
AllICfunctionsOFF
FAULT =HiZ
Reset
Timersreset
Countersreset
FAULT =HiZ
FET off
T < T ?
J J(OFF)
AnyState
ifV(IN)<V(UVLO),
gotoPowerDown
AnyState
ifCE=Hi,
gotoReset
bq24314A
SLUS811 – MARCH 2008
Figure 21. Flow Diagram
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APPLICATION INFORMATION (WITH REFERENCE TO FIGURE 20 )
Selection of R
BAT
Selection of R
CE
, R
FAULT
, and R
PU
Selection of Input and Output Bypass Capacitors
Powering Accessories
bq24314A
SLUS811 – MARCH 2008
It is strongly recommended that the battery not be tied directly to the VBAT pin of the device, as under somefailure modes of the IC, the voltage at the IN pin may appear on the VBAT pin. This voltage can be as high as30V, and applying 30V to the battery in case of the failure of the bq24314A can be hazardous. Connecting theVBAT pin through R
BAT
prevents a large current from flowing into the battery in case of a failure of the IC. In theinterests of safety, R
BAT
should have a very high value. The problem with a large R
BAT
is that the voltage dropacross this resistor because of the VBAT bias current I
VBAT
causes an error in the BV
OVP
threshold. This error isover and above the tolerance on the nominal 4.35V BV
OVP
threshold.
Choosing R
BAT
in the range 100k Ωto 470k Ωis a good compromise. In the case of an IC failure, with R
BAT
equalto 100k Ω, the maximum current flowing into the battery would be (30V – 3V) ÷100k Ω= 246 µA, which is lowenough to be absorbed by the bias currents of the system components. R
BAT
equal to 100k Ωwould result in aworst-case voltage drop of R
BAT
×I
VBAT
= 1mV. This is negligible to compared to the internal tolerance of 50mVon BV
OVP
threshold.
If the Bat-OVP function is not required, the VBAT pin should be connected to VSS.
The CE pin can be used to enable and disable the IC. If host control is not required, the CE pin can be tied toground or left un-connected, permanently enabling the device.
In applications where external control is required, the CE pin can be controlled by a host processor. As in thecase of the VBAT pin (see above), the CE pin should be connected to the host GPIO pin through as large aresistor as possible. The limitation on the resistor value is that the minimum V
OH
of the host GPIO pin less thedrop across the resistor should be greater than V
IH
of the bq24314A CE pin. The drop across the resistor is givenby R
CE
×I
IH
.
The FAULT pin is an open-drain output that goes low during OV, OC, battery-OV, and OT events. If theapplication does not require monitoring of the FAULT pin, it can be left unconnected. But if the FAULT pin has tobe monitored, it should be pulled high externally through R
PU
, and connected to the host through R
FAULT
. R
FAULTprevents damage to the host controller if the bq24314A fails (see above). The resistors should be of high value,in practice values between 22k Ωand 100k Ωshould be sufficient.
The input capacitor C
IN
in Figure 20 is for decoupling, and serves an important purpose. Whenever there is astep change downwards in the system load current, the inductance of the input cable causes the input voltage tospike up. C
IN
prevents the input voltage from overshooting to dangerous levels. It is strongly recommended that aceramic capacitor of at least 1 µF be used at the input of the device. It should be located in close proximity to theIN pin.
C
OUT
in Figure 20 is also important: If a very fast (< 1 µs rise time) overvoltage transient occurs at the input, thecurrent that charges C
OUT
causes the device ’ s current-limiting loop to kick in, reducing the gate-drive to FET Q1.This results in improved performance for input overvoltage protection. C
OUT
should also be a ceramic capacitor ofat least 1 µF, located close to the OUT pin. C
OUT
also serves as the input decoupling capacitor for the chargingcircuit downstream of the protection IC.
In some applications, the equipment that the protection IC resides in may be required to provide power to anaccessory (e.g. a cellphone may power a headset or an external memory card) through the same connector pinsthat are used by the adapter for charging. Figure 22 and Figure 23 illustrate typical charging andaccessory-powering scenarios:
Copyright © 2008, Texas Instruments Incorporated Submit Documentation Feedback 13
Product Folder Link(s): bq24314A
www.ti.com
IN OUT Charger
Accessory
powersupply
EN
DIS
Battery
pack
torestof
system
e.g.
cellphone
AC Adapter
bq24314A
IN OUT Charger
Accessory
powersupply
EN
DIS Battery
pack
torestof
system
e.g.
cellphone
bq24314A
PCB Layout Guidelines:
bq24314A
SLUS811 – MARCH 2008
Figure 22. Charging - The Red Arrows Show the Direction of Current Flow
Figure 23. Powering an Accessory - The Red Arrows Show the Direction of Current Flow
In the second case, when power is being delivered to an accessory, the bq24314A device is required to supportcurrent flow from the OUT pin to the IN pin.
If V
OUT
> UVLO + 0.7V, FET Q1 is turned on, and the reverse current does not flow through the diode butthrough Q1. Q1 will then remain ON as long as V
OUT
> UVLO – V
hys(UVLO)
+ R
DS(on)
×I
ACCESSORY
. Within thisvoltage range, the reverse current capability is the same as the forward capability, 1.5A. It should be noted thatthere is no overcurrent protection in this direction.
•This device is a protection device, and is meant to protect down-stream circuitry from hazardous voltages.Potentially, high voltages may be applied to this IC. It has to be ensured that the edge-to-edge clearances ofPCB traces satisfy the design rules for high voltages.•The device uses SON packages with a PowerPAD™. For good thermal performance, the PowerPAD shouldbe thermally coupled with the PCB ground plane. In most applications, this will require a copper pad directlyunder the IC. This copper pad should be connected to the ground plane with an array of thermal vias.•C
IN
and C
OUT
should be located close to the IC. Other components like R
ILIM
and R
BAT
should also be locatedclose to the IC.
14 Submit Documentation Feedback Copyright © 2008, Texas Instruments Incorporated
Product Folder Link(s): bq24314A
PACKAGING INFORMATION
Orderable Device Status (1) Package
Type Package
Drawing Pins Package
Qty Eco Plan (2) Lead/Ball Finish MSL Peak Temp (3)
BQ24314ADSGR ACTIVE WSON DSG 8 3000 Green (RoHS &
no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR
BQ24314ADSGRG4 ACTIVE WSON DSG 8 3000 Green (RoHS &
no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR
BQ24314ADSGT ACTIVE WSON DSG 8 250 Green (RoHS &
no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR
BQ24314ADSGTG4 ACTIVE WSON DSG 8 250 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 8-Dec-2009
Addendum-Page 1
TAPE AND REEL INFORMATION
*All dimensions are nominal
Device Package
Type Package
Drawing Pins SPQ Reel
Diameter
(mm)
Reel
Width
W1 (mm)
A0
(mm) B0
(mm) K0
(mm) P1
(mm) W
(mm) Pin1
Quadrant
BQ24314ADSGR WSON DSG 8 3000 179.0 8.4 2.2 2.2 1.2 4.0 8.0 Q2
BQ24314ADSGT WSON DSG 8 250 179.0 8.4 2.2 2.2 1.2 4.0 8.0 Q2
PACKAGE MATERIALS INFORMATION
www.ti.com 2-Sep-2010
Pack Materials-Page 1
*All dimensions are nominal
Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm)
BQ24314ADSGR WSON DSG 8 3000 195.0 200.0 45.0
BQ24314ADSGT WSON DSG 8 250 195.0 200.0 45.0
PACKAGE MATERIALS INFORMATION
www.ti.com 2-Sep-2010
Pack Materials-Page 2
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