LM95213CISDX/NOPB - Texas Instruments

LM95213

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SNIS147A –MARCH 2007–REVISED MARCH 2013

2-Diode Input and Local Digital Temperature Sensor with Two-Wire Interface and TCRIT

Outputs

Check for Samples: LM95213

1FEATURES DESCRIPTION

The LM95213 is an 11-bit digital temperature sensor

23• Accurately Senses Die Temperature of 2 with a 2-wire System Management Bus (SMBus)

Remote ICs or Diode Junctions and Local interface that can monitor the temperature of two

Temperature remote diodes as well as its own temperature. The

• 0.125°C LSb Temperature Resolution LM95213 can be used to very accurately monitor the

temperature of up to two external devices such as

• 0.03125°C LSb Remote Temperature microprocessors, graphics processors or diode-

Resolution with Digital Filter Enabled connected 2N3904s.

• +127.875°C/–128°C and 0°C/255°C Remote

Ranges The LM95213 reports temperature in two different

formats for +127.875°C/–128°C range and 0°C/255°C

• Programmable Digital Filters and Analog Front range. The LM95213 TCRIT1, TCRIT2 and TCRIT3

End Filter outputs are triggered when any unmasked channel

• Remote Diode Fault Detection, Model exceeds its corresponding programmable limit and

Selection and Offset Correction can be used to shutdown the system, to turn on the

system fans or as a microcontroller interrupt function.

• Mask and Status Register Support The current status of the TCRIT1, TCRIT2 and

• 3 Programmable TCRIT Outputs with TCRIT3 pins can be read back from the status

Programmable Shared Hysteresis registers. Mask registers are available for further

• Programmable Conversion Rate and Shutdown control of the TCRIT outputs.

Mode One-Shot Conversion Control The LM95213's remote temperature channels have

• SMBus 2.0 Compatible Interface, Supports programmable digital filters to minimize unwanted

TIMEOUT TCRIT events when temperature spikes are

encountered.

• Three-Level Address Pin

• 14-Pin WSON Package For optimum flexibility and accuracy each LM95213

channel includes offset correction registers for

targeting diodes other than the 2N3904. A three level

APPLICATIONS address pin allows connection of up to 3 LM95213s

• Processor/Computer System Thermal to the same SMBus master. The LM95213 includes

Management (e.g. Laptop, Desktop, power saving functions such as: programmable

Workstations, Server) conversion rate, shutdown mode, and turn off of

• Electronic Test Equipment unused channels.

• Office Electronics

Table 1. Key Specifications

VALUE UNIT

Local Temperature Accuracy ±2.0 °C (max)

Remote Diode Temperature Accuracy ±1.1 °C (max)

Supply Voltage 3.0 to 3.6 V

Average Supply Current (1Hz conversion rate) 0.57 mA (typ)

1Please 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.

2TruTherm is a trademark of Texas Instruments.

3All other trademarks are the property of their respective owners.

Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

necessarily include testing of all parameters.

3.0V-3.6V

LM95213

Local

Diode Selector

'-6Converter

11-Bit or

10-Bit Plus Sign

Remote

10-bit Plus Sign

Local

Temperature

Sensor

Circuitry

Local

Temperature

Registers

Limit, Status

and

Mask

Registers

Remote 1

Digital Filter

Remote 1

Temperature

Registers

Remote 1 Offset

SMBus

Interface

Remote 2

Digital Filter

Remote 2

Temperature

Registers

Remote 2 Offset

Conversion Rate

Rgister

Diode

Configuration

Registers

Control Logic

D-

Remote

Diode2

Selector

D2+

Remote

Diode1

Selector

D1+

General

Configuration

Registers

T_CRIT

Control

Logic

SMBCLK

SMBDAT

TCRIT3

TCRIT2

TCRIT1

LM95213

TCRIT3NC 141

VDD SMBCLK2 13

NC SMBDAT3 12

NC TCRIT24 11

D- TCRIT15 10

D2+ A06 9

D1+ GND

7 8

LM95213

SNIS147A –MARCH 2007–REVISED MARCH 2013

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Connection Diagram

Figure 1. 14-Lead WSON - TOP VIEW

See NHL0014B Package

Simplified Block Diagram

Product Folder Links: LM95213

LM95213

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SNIS147A –MARCH 2007–REVISED MARCH 2013

PIN DESCRIPTIONS

Label Pin # Function Typical Connection

NC 1 No Connect Not connected. May be left floating, connected to GND or VDD.

VDD 2 Positive Supply Voltage Input DC Voltage from 3.0 V to 3.6 V. VDD should be bypassed with

a 0.1µF capacitor in parallel with 100pF. The 100pF capacitor

should be placed as close as possible to the power supply pin.

Noise should be kept below 200 mVp-p, a 10 µF capacitor may

be required to achieve this.

NC 3 No Connect Not connected. May be left floating, connected to GND or VDD.

NC 4 No Connect Not connected. May be left floating, connected to GND or VDD.

D−5 Diode Return Current Sink To all Diode Cathodes. Common D- pin for all two remote

diodes.

D2+ 6 Diode Current Source To second Diode Anode. Connected to remote discrete diode-

connected transistor junction or to the diode-connected

transistor junction on a remote IC whose die temperature is

being sensed. A capacitor is not required between D2+ and D-.

A 100 pF capacitor between D2+ and D- can be added and

may improve perfomance in noisy systems. Float this pin if this

thermal diode is not used.

D1+ 7 Diode Current Source To first Diode Anode. Connected to remote discrete diode-

connected transistor junction or to the diode-connected

transistor junction on a remote IC whose die temperature is

being sensed. A capacitor is not required between D1+ and D-.

A 100 pF capacitor between D1+ and D- can be added and

may improve perfomance in noisy systems. Float this pin if this

thermal diode is not used.

GND 8 Power Supply Ground System low noise ground.

A0 9 Dgital Input SMBus slave address select pin. Selects one of three

addresses. Can be tied to VDD, GND, or to the middle of a

resistor divider connected between VDD and GND.

TCRIT1 10 Digital Output, Open-Drain Critical temperature output 1. Requires pull-up resistor. Active

"LOW".

TCRIT2 11 Digital Output, Open-Drain Critical temperature output 2. Requires pull-up resistor. Active

"LOW".

SMBDAT 12 SMBus Bi-Directional Data Line, From and to Controller; may require an external pull-up resistor

Open-Drain Output

SMBCLK 13 SMBus Clock Input From Controller; may require an external pull-up resistor

TCRIT3 14 Digital Output, Open-Drain Critical temperature output 3. Requires pull-up resistor. Active

"LOW".

Product Folder Links: LM95213

SMBus

Master

* Note, place close to LM95213 pins.

** Note, optional - place close to LM95213 pins.

LM95213

VDD

SMBCLK

C1*

100 pF

0.1 PF

SMBCLK

SMBDAT

C5**

100 pF

+3.3V

Standby

1.3k R5

1.3k

D-

D2+

D1+

SMBDAT

PROCESSOR

MMBT3904

C4**

100 pF

10k

DIMM

10 PF

TCRIT2

TCRIT1

TCRIT3

GND

LM95213

SNIS147A –MARCH 2007–REVISED MARCH 2013

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Typical Application

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.

Absolute Maximum Ratings (1)

Supply Voltage −0.3V to 6.0V

Voltage at SMBDAT, SMBCLK,

TCRIT1, TCRIT2, TCRIT3 −0.5V to 6.0V

Voltage at Other Pins −0.3V to (VDD + 0.3V)

D−Input Current ±1 mA

Input Current at All Other Pins (2) ±5 mA

Package Input Current (2) 30 mA

SMBDAT, TCRIT1, TCRIT2,

TCRIT3 Output Sink Current 10 mA

Storage Temperature −65°C to +150°C

ESD Susceptibility (3) Human Body Model 2000V

Machine Model 200V

Charge Device Model 1000V

Soldering process must comply with reflow temperature profile specifications. Refer to http://www.ti.com/packaging (4)

(1) Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. DC and AC electrical specifications do not

apply when operating the device beyond its rated operating conditions.

(2) When the input voltage (VI) at any pin exceeds the power supplies (VI< GND or VI> VDD), the current at that pin should be limited to

5 mA. Parasitic components and or ESD protection circuitry are shown in the table below for the LM95213's pins.

(3) Human body model, 100 pF discharged through a 1.5 kΩresistor. Machine model, 200 pF discharged directly into each pin. Charged

Device Model (CDM) simulates a pin slowly acquiring charge (such as from a device sliding down the feeder in an automated

assembler) then rapidly being discharged.

(4) Reflow temperature profiles are different for packages containing lead (Pb) than for those that do not.

Product Folder Links: LM95213

LM95213

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SNIS147A –MARCH 2007–REVISED MARCH 2013

Operating Ratings(1)(2)

Operating Temperature Range −40°C to +140°C

Electrical Characteristics Temperature Range TMIN ≤TA≤TMAX

LM95213CISD −40°C ≤TA≤+125°C

Supply Voltage Range (VDD) +3.0V to +3.6V

(1) Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. DC and AC electrical specifications do not

apply when operating the device beyond its rated operating conditions.

(2) Thermal resistance junction-to-ambient when attached to a 4 layer printed circuit board per JEDEC standard JESD51-7:

14-lead WSON = 90°C/W (no thermal vias, no airflow)

14-lead WSON = 63°C/W (1 thermal via, no airflow)

14-lead WSON = 43°C/W (6 thermal vias, no airflow)

14-lead WSON = 31°C/W (6 thermal vias, 900 ln. ft. / min. airflow)

Note, all quoted values include +15% error factor from nominal value.

Temperature-to-Digital Converter Electrical Characteristics

Unless otherwise noted, these specifications apply for VDD = +3.0Vdc to 3.6Vdc. Boldface limits apply for TA= TJ= TMIN ≤

TA≤TMAX;all other limits TA= TJ= +25°C, unless otherwise noted.

Parameter Conditions Typical(1) Limits(2) Units

(Limit)

Temperature Error Using Local Diode TA= -40°C to +125°C, (3) ±1 ±2 °C (max)

Temperature Error Using Remote Diode (4) TA= +25°C to +85°C MMBT3904 ±1.1 °C (max)

TD= +60°C to +100°C Transistor

TA= +25°C to +85°C MMBT3904 ±1.3 °C (max)

TD=−40°C to +125°C Transistor

TA=−40°C to +85°C MMBT3904 ±3.0 °C (max)

TD=−40°C to +125°C Transistor

TA=−40°C to +85°C MMBT3904 ±3.3 °C (max)

TD= 125°C to +140°C Transistor

Local Diode Measurement Resolution 11 Bits

0.125 °C

Remote Diode Measurement Resolution Digital Filter Off 11 Bits

0.125 °C

Digital Filter On (Remote Diodes 1 and 2 13 Bits

only) 0.03125 °C

Conversion Time of All Temperatures at the All Channels are Enabled in Default State 1100 1210 ms (max)

Fastest Setting (5) 1 External Channel 31 34 ms (max)

Local only 30 33 ms (max)

Quiescent Current (6) SMBus Inactive, 1Hz Conversion Rate, 570 800 µA (max)

channels in default state

Shutdown 360 µA

D−Source Voltage 0.4 V

Remote Diode Source Current High level 160 230 µA (max)

Low level 10

Power-On Reset Threshold Measured on VDD input, falling edge 2.8 V (max)

1.6 V (min)

TCRIT1 Pin Temperature Threshold Default Diodes only +110 °C

TCRIT2 Pin Temperature Threshold Default all channels +85 °C

(1) Typicals are at TA= 25°C and represent most likely parametric norm.

(2) Limits are guaranteed to National's AOQL (Average Outgoing Quality Level).

(3) Local temperature accuracy does not include the effects of self-heating. The rise in temperature due to self-heating is the product of the

internal power dissipation of the LM95213 and the thermal resistance. See Thermal Resistance note under Operating Ratings for the

thermal resistance to be used in the self-heating calculation.

(4) The accuracy of the LM95213CISD is guaranteed when using a typical thermal diode of an MMBT3904 diode-connected transistor. For

further information on other thermal diodes see applications DIODE NON-IDEALITY.

(5) This specification is provided only to indicate how often temperature data is updated. The LM95213 can be read at any time without

regard to conversion state (and will yield last conversion result).

(6) Quiescent current will not increase substantially with an SMBus communication.

Product Folder Links: LM95213

LM95213

SNIS147A –MARCH 2007–REVISED MARCH 2013

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Logic Electrical Characteristics

DIGITAL DC CHARACTERISTICS

Unless otherwise noted, these specifications apply for VDD = +3.0Vdc to 3.6Vdc. Boldface limits apply for TA= TJ= TMIN to

TMAX;all other limits TA= TJ=+25°C, unless otherwise noted.

Symbol Parameter Conditions Typical(1) Limits(2) Units

(Limit)

SMBDAT, SMBCLK INPUTS

VIN(1) Logical “1” Input Voltage 2.1 V (min)

VIN(0) Logical “0”Input Voltage 0.8 V (max)

VIN(HYST) SMBDAT and SMBCLK Digital Input Hysteresis 400 mV

IIN(1) Logical “1” Input Current VIN = VDD 0.005 10 µA (max)

IIN(0) Logical “0” Input Current VIN = 0V −0.005 -10 µA (max)

CIN Input Capacitance 5 pF

A0 DIGITAL INPUT

VIH Input High Voltage 0.90 × VDD V (min)

VIM Input Middle Voltage 0.57 × VDD V (max)

0.43 × VDD V (min)

VIL Input Low Voltage 0.10 × VDD V (max)

IIN(1) Logical "1" Input Current VIN = VDD −0.005 −10 µA (min)

IIN(0) Logical "0" Input Current VIN = 0V 0.005 10 µA (max)

CIN Input Capacitance 5 pF

SMBDAT, TCRIT1, TCRIT2, TCRIT3 DIGITAL OUTPUTS

IOH High Level Output Current VOH = VDD 10 µA (max)

VOL(SMBDAT) SMBus Low Level Output Voltage IOL = 4 mA 0.4 V (max)

IOL = 6 mA 0.6 V (max)

VOL(TCRIT) TCRIT1, TCRIT2, TCRIT3 Low Level Output IOL= 6 mA 0.4 V (max)

Voltage

COUT Digital Output Capacitance 5 pF

(1) Typicals are at TA= 25°C and represent most likely parametric norm.

(2) Limits are guaranteed to National's AOQL (Average Outgoing Quality Level).

SMBus DIGITAL SWITCHING CHARACTERISTICS

Unless otherwise noted, these specifications apply for VDD=+3.0 Vdc to +3.6 Vdc, CL(load capacitance) on output lines = 80

pF. Boldface limits apply for TA= TJ= TMIN to TMAX;all other limits TA= TJ= +25°C, unless otherwise noted.

The switching characteristics of the LM95213 fully meet or exceed the published specifications of the SMBus version 2.0. The

following parameters are the timing relationships between SMBCLK and SMBDAT signals related to the LM95213. They

adhere to but are not necessarily the SMBus bus specifications.

Symbol Parameter Conditions Typical(1) Limits(2) Units

(Limit)

fSMB SMBus Clock Frequency 100 kHz (max)

10 kHz (min)

tLOW SMBus Clock Low Time from VIN(0)max to VIN(0)max 4.7 µs (min)

25 ms (max)

tHIGH SMBus Clock High Time from VIN(1)min to VIN(1)min 4.0 µs (min)

tR,SMB SMBus Rise Time See (3) 1 µs (max)

tF,SMB SMBus Fall Time See (4) 0.3 µs (max)

tOF Output Fall Time CL= 400 pF, 250 ns (max)

IO= 3 mA, (4)

(1) Typicals are at TA= 25°C and represent most likely parametric norm.

(2) Limits are guaranteed to National's AOQL (Average Outgoing Quality Level).

(3) The output rise time is measured from (VIN(0)max −0.15V) to (VIN(1)min + 0.15V).

(4) The output fall time is measured from (VIN(1)min + 0.15V) to (VIN(0)max −0.15V).

Product Folder Links: LM95213

LM95213

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SNIS147A –MARCH 2007–REVISED MARCH 2013

SMBus DIGITAL SWITCHING CHARACTERISTICS

Unless otherwise noted, these specifications apply for VDD=+3.0 Vdc to +3.6 Vdc, CL(load capacitance) on output lines = 80

pF. Boldface limits apply for TA= TJ= TMIN to TMAX;all other limits TA= TJ= +25°C, unless otherwise noted.

The switching characteristics of the LM95213 fully meet or exceed the published specifications of the SMBus version 2.0. The

following parameters are the timing relationships between SMBCLK and SMBDAT signals related to the LM95213. They

adhere to but are not necessarily the SMBus bus specifications.

Symbol Parameter Conditions Typical(1) Limits(2) Units

(Limit)

tTIMEOUT SMBDAT and SMBCLK Time Low for Reset of 25 ms (min)

Serial Interface (5) 35 ms (max)

tSU;DAT Data In Setup Time to SMBCLK High 250 ns (min)

tHD;DAT Data Out Stable after SMBCLK Low 300 ns (min)

1075 ns (max)

tHD;STA Start Condition SMBDAT Low to SMBCLK Low 100 ns (min)

(Start condition hold before the first clock falling

edge)

tSU;STO Stop Condition SMBCLK High to SMBDAT Low 100 ns (min)

(Stop Condition Setup)

tSU;STA SMBus Repeated Start-Condition Setup Time, 0.6 µs (min)

SMBCLK High to SMBDAT Low

tBUF SMBus Free Time Between Stop and Start 1.3 µs (min)

Conditions

(5) Holding the SMBDAT and/or SMBCLK lines Low for a time interval greater than tTIMEOUT will reset the LM95213's SMBus state machine,

therefore setting SMBDAT and SMBCLK pins to a high impedance state.

Product Folder Links: LM95213

SNP

GND

V+

6.5V

D3 ESD

CLAMP

VIH

VIL

SMBCLK

VIH

VIL

SMBDAT

tBUF tHD;STA

tLOW

tHD;DAT tHIGH

tSU;DAT tSU;STA tSU;STO

LM95213

SNIS147A –MARCH 2007–REVISED MARCH 2013

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Figure 2. SMBus Communication

Pin # Label Circuit Circuits for Pin ESD Protection Structure

1 NC –

2 VDD A

3 NC –

4 NC –

5 D- A

6 D2+ A Circuit A

7 D1+ A

8 GND –

9 A0 B

10 TCRIT1 B

11 TCRIT2 B

12 SMBDAT B

13 SMBCLK B Circuit B

14 TCRIT2 B

Product Folder Links: LM95213

0.01 0.1 1 10

CONVERSION TIME (sec)

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

AVERAGE IDD (mA)

VDD = +3.3V

TA = 25°C

LM95213

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SNIS147A –MARCH 2007–REVISED MARCH 2013

Typical Performance Characteristics

Thermal Diode Capacitor or PCB

Leakage Current Effect on

Conversion Rate Effect on Average Power Supply Current Remote Diode Temperature Reading

Figure 3. Figure 4.

Remote Temperature Reading Sensitivity to

Thermal Diode Filter Capacitance,

Figure 5.

Product Folder Links: LM95213

LM95213

SNIS147A –MARCH 2007–REVISED MARCH 2013

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FUNCTIONAL DESCRIPTION

LM95213 is an 11-bit digital temperature sensor with a 2-wire System Management Bus (SMBus) interface that

can monitor the temperature of two remote diodes as well as its own temperature. The LM95213 can be used to

very accurately monitor the temperature of up to two external devices such as microprocessors, graphics

processors or diode-connected 2N3904 transistor.

The LM95213 reports temperature in two different formats for +127.875°C/–128°C range and 0°C/255°C range.

The LM95213 has a Sigma-Delta ADC (Analog-to-Digital Converter) core which provides the first level of noise

imunity. For improved performance in a noisy environment the LM95213 includes programmable digital filters for

Remote Diode 1 and 2 temperature readings. When the digital filters are invoked the resolution for Remote Diode

1 and 2 readings increases to 0.03125°C. For maximum flexibility and best accuracy the LM95213 includes offset

registers that allow calibration of other diode types.

Diode fault detection circuitry in the LM95213 can detect the absence or fault state of a remote diode: whether

D+ is shorted to VDD, D- or ground, or whether D+ is floating.

The LM95213 TCRIT1, TCRIT2 and TCRIT3 active low outputs are triggered when any unmasked channel

exceeds its corresponding programmable limit and can be used to shutdown the system, to turn on the system

fans or as a microcontroller interrupt function. The current status of the TCRIT1, TCRIT2 and TCRIT3 pins can

be read back from the status registers via the SMBus interface. The remote channels have two separate limits

each that control the TCRIT1 and TCRIT2 pins. The TCRIT3 pin shares the limits of the TCRIT2 pin but allows

for different masking options. All limits have a shared programmable hysteresis register.

Remote Diode temperature channels have programmable digital filters in order to avoid false triggering the

TCRIT pins.

LM95213 has a three-level address pin to connect up to 3 devices to the same SMBus master. LM95213 also

has programmable conversion rate register as well as a shutdown mode for power savings. One round of

conversions can be triggered in shutdown mode by writing to the one-shot register through the SMBus interface.

LM95213 can be programmed to turn off unused channels for more power savings.

The LM95213 register set has an 8-bit data structure and includes:

1. Temperature Value Registers with signed format

– Most-Significant-Byte (MSB) and Least-Significant-Byte (LSB) Local Temperature

– MSB and LSB Remote Temperature 1

– MSB and LSB Remote Temperature 2

2. Temperature Value Registers with unsigned format

– MSB and LSB Remote Temperature 1

– MSB and LSB Remote Temperature 2

3. Diode Configuration Registers

– Remote 1 Offset

– Remote 2 Offset

4. General Configuration Registers

– Configuration (Standby, Conversion Rate)

– Channel Conversion Enable

– Filter Setting for Remote 1 and 2

– 1-Shot

5. Status Registers

– Main Status Register (Busy bit, Not Ready, Status Register 1 to 4 Flags)

– Status 1 (diode fault)

– Status 2 (TCRIT1)

– Status 3 (TCRIT2)

– Status 4 (TCRIT3)

6. Mask Registers

– TCRIT1 Mask

– TCRIT2 Mask

Product Folder Links: LM95213

0.01 0.1 1 10

CONVERSION TIME (sec)

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

AVERAGE IDD (mA)

VDD = +3.3V

TA = 25°C

LM95213

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SNIS147A –MARCH 2007–REVISED MARCH 2013

– TCRIT3 Mask

7. Limit Registers

– Local Tcrit Limit

– Remote 1 Tcrit-1 Limit

– Remote 2 Tcrit-1 Limit

– Remote 1 Tcrit-2 and Tcrit-3 Limit

– Remote 2 Tcrit-2 and Tcrit-3 Limit

– Common Tcrit Hysteresis

8. Manufacturer ID Register

9. Revision ID Register

CONVERSION SEQUENCE

The LM95213 takes approximately 92 ms to convert the Local Temperature, Remote Temperatures 1 and 2, and

to update all of its registers. These conversions for each thermal diode are addressed in a round robin sequence.

Only during the conversion process the busy bit (D7) in Status register (02h) is high. The conversion rate may be

modified by the Conversion Rate bits found in the Configuration Register (03h). When the conversion rate is

modified a delay is inserted between each round of conversions, the actual time for each round remains at 92 ms

(typical all channels enabled). The time a round takes depends on the number of channels that are on. Different

conversion rates will cause the LM95213 to draw different amounts of average supply current as shown in

Figure 6. This curve assumes all the channels are on. If channels are turned off the average current will drop

since the round robin time will decrease and the shutdown time will increase during each conversion interval.

Figure 6. Conversion Rate Effect on Power Supply Current

POWER-ON-DEFAULT STATES

LM95213 always powers up to these known default states. The LM95213 remains in these states until after the

first conversion.

1. All Temperature readings set to 0°C until the end of the first conversion

2. Remote offset for all channels 0°C

3. Configuration: Active converting

4. Continuous conversion with all channels enabled, time = 1s

5. Enhanced digital filter enabled for Remote 1 and 2

6. Status Registers depends on state of thermal diode inputs

7. Local and Remote Temperature Limits for TCRIT1, TCRIT2 and TCRIT3 outputs:

Product Folder Links: LM95213

LM95213

SNIS147A –MARCH 2007–REVISED MARCH 2013

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Output Pin Temperature Channel Limit

Remote 2 Remote 1 Local

(°C) (°C) (°C)

TCRIT1 110 110 Masked,

TCRIT2 85 85 85

TCRIT3 Masked, Masked, Masked,

85 85 85

8. Manufacturers ID set to 01h

9. Revision ID set to 7Bh

SMBus INTERFACE

The LM95213 operates as a slave on the SMBus, so the SMBCLK line is an input and the SMBDAT line is

bidirectional. The LM95213 never drives the SMBCLK line and it does not support clock stretching. According to

SMBus specifications, the LM95213 has a 7-bit slave address. Three SMBus device address can be selected by

connecting A0 (pin 6) to either Low, Mid-Supply or High voltages. The LM95213 has the following SMBus slave

address:

A0 Pin State SMBus Device Address A[6:0]

Hex Binary

Low 18h 001 1000

Mid-Supply 2Ah 010 1010

High 2Bh 010 1011

TEMPERATURE CONVERSION SEQUENCE

Each of the 3 temperature channels of LM95213 can be turned OFF independent from each other via the

Channel Enable Register. Turning off unused channels will increase the conversion speed in the fastest

conversion speed mode. If the slower conversion speed settings are used, disabling unused channels will reduce

the average power consumption of LM95213.

DIGITAL FILTER

In order to suppress erroneous remote temperature readings due to noise as well as increase the resolution of

the temperature, the LM95213 incorporates a digital filter for Remote 1 and 2 Temperature Channels. When a

filter is enabled the filtered readings are used for the TCRIT comparisons. There are two possible digital filter

settings that are enabled through the Filter Setting Register at register address 0Fh. The filter for each channel

can be set according to the following table:

R1F[1:0] or R2F[1:0] Filter Setting

0 0 No Filter

0 1 Filter (equivalent to Level 2 filter of the LM86/LM89)

1 0 Reserved

1 1 Enhanced Filter (Filter with transient noise clipping)

Product Folder Links: LM95213

0 50 100 150 200

SAMPLE NUMBER

TEMPERATURE (oC)

LM95213 with

Filter On

LM95213 with

Filter Off

LM95213

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SNIS147A –MARCH 2007–REVISED MARCH 2013

Figure 7 describes the filter output in response to a step input and an impulse input.

a) Seventeen and fifty degree step b) Impulse response with input c) Impulse response with input

response transients less than 4°C transients great than 4°C

Figure 7. Filter Impulse and Step Response Curves

Figure 8. Digital Filter Response in a typical processor system. The filter curves were purposely offset

for clarity.

Figure 8 shows the filter in use in a typical processor system. Note that the two curves have been purposely

offset for clarity. Inserting the filter does not induce an offset as shown.

TEMPERATURE DATA FORMAT

Temperature data can only be read from the Local and Remote Temperature value registers. The data format for

all temperature values is left justified 16-bit word available in two 8-bit registers. Unused bits will always report

"0". All temperature data is clamped and will not roll over when a temperature exceeds full-scale value.

Remote temperature data for all channels can be represented by an 11-bit, two's complement word or unsigned

binary word with an LSb (Least Significant Bit) equal to 0.125°C.

Table 2. 11-bit, 2's complement (10-bit plus sign)

Temperature Digital Output

Binary Hex

+125°C 0111 1101 0000 0000 7D00h

+25°C 0001 1001 0000 0000 1900h

+1°C 0000 0001 0000 0000 0100h

+0.125°C 0000 0000 0010 0000 0020h

Product Folder Links: LM95213

LM95213

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Table 2. 11-bit, 2's complement (10-bit plus sign) (continued)

Temperature Digital Output

Binary Hex

0°C 0000 0000 0000 0000 0000h

−0.125°C 1111 1111 1110 0000 FFE0h

−1°C 1111 1111 0000 0000 FF00h

−25°C 1110 0111 0000 0000 E700h

−55°C 1100 1001 0000 0000 C900h

Table 3. 11-bit, unsigned binary

Temperature Digital Output

Binary Hex

+255.875°C 1111 1111 1110 0000 FFE0h

+255°C 1111 1111 0000 0000 FF00h

+201°C 1100 1001 0000 0000 C900h

+125°C 0111 1101 0000 0000 7D00h

+25°C 0001 1001 0000 0000 1900h

+1°C 0000 0001 0000 0000 0100h

+0.125°C 0000 0000 0010 0000 0020h

0°C 0000 0000 0000 0000 0000h

When the digital filter is enabled on Remote 1 and 2 channels temperature data is represented by a 13-bit

unsigned binary or 12-bit plus sign (two's complement) word with an LSb equal to 0.03125°C.

Table 4. 13-bit, 2's complement (12-bit plus sign)

Temperature Digital Output

Binary Hex

+125°C 0111 1101 0000 0000 7D00h

+25°C 0001 1001 0000 0000 1900h

+1°C 0000 0001 0000 0000 0100h

+0.03125°C 0000 0000 0000 1000 0008h

0°C 0000 0000 0000 0000 0000h

−0.03125°C 1111 1111 1111 1000 FFF8h

−1°C 1111 1111 0000 0000 FF00h

−25°C 1110 0111 0000 0000 E700h

−55°C 1100 1001 0000 0000 C900h

Table 5. 13-bit, unsigned binary

Temperature Digital Output

Binary Hex

+255.875°C 1111 1111 1110 0000 FFE0h

+255°C 1111 1111 0000 0000 FF00h

+201°C 1100 1001 0000 0000 C900h

+125°C 0111 1101 0000 0000 7D00h

+25°C 0001 1001 0000 0000 1900h

+1°C 0000 0001 0000 0000 0100h

+0.03125°C 0000 0000 0000 1000 0008h

0°C 0000 0000 0000 0000 0000h

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Local Temperature data is only represented by an 11-bit, two's complement, word with an LSb equal to 0.125°C.

Table 6. 11-bit, 2's complement (10-bit plus sign)

Temperature Digital Output

Binary Hex

+125°C 0111 1101 0000 0000 7D00h

+25°C 0001 1001 0000 0000 1900h

+1°C 0000 0001 0000 0000 0100h

+0.125°C 0000 0000 0010 0000 0020h

0°C 0000 0000 0000 0000 0000h

−0.125°C 1111 1111 1110 0000 FFE0h

−1°C 1111 1111 0000 0000 FF00h

−25°C 1110 0111 0000 0000 E700h

−55°C 1100 1001 0000 0000 C900h

SMBDAT OPEN-DRAIN OUTPUT

The SMBDAT output is an open-drain output and does not have internal pull-ups. A “high” level will not be

observed on this pin until pull-up current is provided by some external source, typically a pull-up resistor. Choice

of resistor value depends on many system factors but, in general, the pull-up resistor should be as large as

possible without effecting the SMBus desired data rate. This will minimize any internal temperature reading

errors due to internal heating of the LM95213. The maximum resistance of the pull-up to provide a 2.1V high

level, based on LM95213 specification for High Level Output Current with the supply voltage at 3.0V, is 82 kΩ

(5%) or 88.7 kΩ(1%).

TCRIT1, TCRIT2, AND TCRIT3 OUTPUTS

The LM95213's TCRIT pins are active-low open-drain outputs and do not include internal pull-up resistors. A

“high” level will not be observed on these pins until pull-up current is provided by some external source, typically

a pull-up resistor. Choice of resistor value depends on many system factors but, in general, the pull-up resistor

should be as large as possible without effecting the performance of the device receiving the signal. This will

minimize any internal temperature reading errors due to internal heating of the LM95213. The maximum

resistance of the pull-up to provide a 2.1V high level, based on LM95213 specification for High Level Output

Current with the supply voltage at 3.0V, is 82 kΩ(5%) or 88.7 kΩ(1%). The three TCRIT pins can each sink 6

mA of current and still guarantee a "Logic Low" output voltage of 0.4V. If all three pins are set at maximum

current this will cause a power dissipation of 7.2 mW. This power dissipation combined with a thermal resistance

of 77.8°C/W will cause the LM95213's junction temperature to rise approximately 0.6°C and thus cause the Local

temperature reading to shift. This can only be cancelled out if the environment that the LM95213 is enclosed in

has stable and controlled air flow over the LM95213, as airflow can cause the thermal resistance to change

dramatically.

TCRIT LIMITS AND TCRIT OUTPUTS

Figure 9 describes a simplified diagram of the temperature comparison and status register logic. Figure 10

describes a simplified logic diagram of the circuitry associated with the status registers, mask registers and the

TCRIT output pins.

Product Folder Links: LM95213

Common Tcrit Hysteresis

Remote Temp 2

Remote 2 Tcrit-1 Limit

AB

AtB

Remote 1 Tcrit2 & Tcrit-3

Limit

AB

AtB

Local Temp

Local Tcrit Limit

AB

AtB

Status 4

(TCRIT3)

R2T3

R1T3

LT3

Remote 2 Tcrit-2 & Tcrit-3

Limit

AB

AtB

Remote Temp 1

Remote 1 Tcrit-1 Limit

AB

AtB

RStatus 3

(TCRIT2)

R2T2

R1T2

LT2

Status 2

(TCRIT1)

R2T1

R1T1

LT1

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Figure 9. Temperature Comparison Logic and Status Register Simplified Diagram

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TCRIT2

Status 3

(TCRIT2)

R2T2

R1T2

LT2

TCRIT2

Mask

R2T2M

R1T2M

LTM

Status 1

(Diode Fault)

R2DO

R2DS

R1DO

R1DS

TCRIT1

Status 1

(Diode Fault)

R2DO

R2DS

R1DO

R1DS

R2T1

R1T1

LT1

R2T1M

R1T1M

LTM

Status 2

(TCRIT1)

TCRIT1

Mask

LM95213

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a) TCRIT1 Mask Register, Status Register 1 and 2, and TCRIT1 output logic diagram.

b) TCRIT2 Mask Register, Status Register 1 and 3, and TCRIT2 output logic diagram.

Product Folder Links: LM95213

TCRIT3

R2T3

R1T3

LT3

R2T2M

R1T2M

LTM

Status 1

(Diode Fault)

R2DO

R2DS

R1DO

R1DS

Status 4

(TCRIT3)

TCRIT3

Mask

LM95213

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c) TCRIT3 Mask Register, Status Register 1 and 4, and TCRIT3 output logic diagram.

Figure 10. Logic diagrams for the TCRIT1, TCRIT2, and TCRIT3 outputs.

If enabled, local temperature is compared to the user programmable Local Tcrit Limit Register (Default Value =

85°C). The result of this comparison is stored in Status Register 2, Status Register 3 and Status Register 4 (see

Figure 9). The comparison result can trigger TCRIT1 pin, TCRIT2 pin or TCRIT3 pin depending on the settings in

the TCRIT1 Mask, TCRIT2 Mask and TCRIT3 Mask Registers (see Figure 10). The comparison result can also

be read back from the Status Register 2, Status Register 3 and Status Register 4.

If enabled, remote temperature 1 is compared to the user programmable Remote 1 Tcrit-1 Limit Register (Default

Value 110°C) and Remote 1 Tcrit-2 Limit Register (Default Value = 85°C). The result of this comparison is stored

in Status Register 2, Status Register 3 and Status Register 4 (see Figure 9). The comparison result can trigger

TCRIT1 pin, TCRIT2 pin or TCRIT3 pin depending on the settings in the TCRIT1 Mask, TCRIT2 Mask and

TRCIT3 Mask Registers (see Figure 10). The comparison result can also be read back from the Status Register

2, Status Register 3 and Status Register 4. The remote temperature 2 operates in a similar manner to remote

temperature 1 using its associated user programmable limit registers: Remote 2 Tcrit-1 Limit Register (Default

Value 110°C) and Remote 2 Tcrit-2 Limit Register (Default Value = 85°C).

Table 7. Limit assignments for each TCRIT output pin:

TCRIT1 TCRIT2 TCRIT3

Remote 2 Remote 2 Remote 2 Remote 2

Tcrit-1 Limit Tcrit-2 Limit Tcrit-2 Limit

Remote 1 Remote 1 Remote 1 Remote 1

Tcrit-1 Limit Tcrit-2 Limit Tcrit-2 Limit

Local Local Local Local

Tcrit Limit Tcrit Limit Tcrit Limit

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T_CRITn

Output Pin

Local Tcrit Limit

Local

Temperature

Status bit LTn

Local Tcrit Limit -

Common Hysteresis

Common

Hysteresis

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Figure 11. TCRIT response diagram (masking options not included)

The TCRIT response diagram of Figure 11 shows the local temperature interaction with the Tcrit limit and

hysteresis value. As can be seen in the diagram when the local temperature exceeds the Tcrit limit register value

the LTn Status bit is set and the T_CRITn output(s) is/are activated. The Status bit(s) and outputs are not

deactivated until the temperature goes below the value calculated by subtracting the Common Hysteresis value

programmed from the limit. This diagram mainly shows an example function of the hysteresis and is not meant to

show complete function of the possible settings and options of all the TCRIT outputs and limit values.

DIODE FAULT DETECTION

The LM95213 is equipped with operational circuitry designed to detect fault conditions concerning the remote

diodes. In the event that the D+ pin is detected as shorted to GND, D−, VDD or D+ is floating, the Remote

Temperature reading is –128.000 °C if signed format is selected and 0 °C if unsigned format is selected. In

addition, the appropriate status register bits RD1M or RD2M (D1 or D0) are set.

COMMUNICATING WITH THE LM95213

The data registers in the LM95213 are selected by the Command Register. At power-up the Command Register

is set to “00”, the location for the Read Local Temperature Register. The Command Register latches the last

location it was set to. Each data register in the LM95213 falls into one of three types of user accessibility:

1. Read only

2. Write only

3. Write/Read same address

AWrite to the LM95213 will always include the address byte and the command byte. A write to any register

requires one data byte.

Reading the LM95213 can take place either of two ways:

1. If the location latched in the Command Register is correct (most of the time it is expected that the Command

read from the LM95213), then the read can simply consist of an address byte, followed by retrieving the data

byte.

2. If the Command Register needs to be set, then an address byte, command byte, repeat start, and another

address byte will accomplish a read.

The data byte has the most significant bit first. At the end of a read, the LM95213 can accept either acknowledge

or No Acknowledge from the Master (No Acknowledge is typically used as a signal for the slave that the Master

has read its last byte). It takes the LM95213 95 ms (typical, all channels enabled) to measure the temperature of

the remote diodes and internal diode. When retrieving all 11 bits from a previous remote diode temperature

measurement, the master must insure that all 11 bits are from the same temperature conversion. This may be

achieved by reading the MSB register first. The LSB will be locked after the MSB is read. The LSB will be

unlocked after being read. If the user reads MSBs consecutively, each time the MSB is read, the LSB associated

with that temperature will be locked in and override the previous LSB value locked-in.

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D7 D6 D5 D4 D3 D2 D1 D0

1 9 1 9

Ack

LM95213

Start by

Master

R/W

Frame 1

Serial Bus Address Byte Frame 2

Data Byte from the LM95213

NoAck

Master

SMBCLK

SMBDAT Stop

Master

A5 A3 A2 A0

A6 A4 A1

D7 D6 D5 D4 D3 D2 D1 D0

1 9 1 9

Ack

LM95213

Start by

Master

R/W

Frame 1

Serial Bus Address Byte Frame 2

Command Byte

Ack by

LM95213

SMBCLK

SMBDAT A5 A3 A2 A0A6 A4 A1 Stop

Master

D7 D6 D5 D4 D3 D2 D1 D0

1 9 1 9

Ack

LM95213

Start by

Master

R/W

Frame 1

Serial Bus Address Byte Frame 2

Command Byte

Ack

LM95213

D7 D6 D5 D4 D3 D2 D1 D0

1 9

Frame 3

Data Byte

Ack by

LM95213Stop

Master

SMBCLK

SMBDAT

SMBCLK

(Continued)

SMBDAT

(Continued)

A5 A3 A2 A0A6 A4 A1

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SMBus Timing Diagrams

Figure 12. Serial Bus Write to the internal Command Register followed by a the Data Byte

Figure 13. Serial Bus Write to the Internal Command Register

Figure 14. Serial Bus Read from a Register with the Internal Command Register preset to desired value.

Product Folder Links: LM95213

D7 D6 D5 D4 D3 D2 D1 D0

1 9 1 9

Ack

LM95213

Start by

Master Repeat

Start by

Master

R/W

Frame 1

Serial Bus Address Byte Frame 2

Command Byte

Ack

LM95213

D7 D6 D5 D4 D3 D2 D1 D0

1 9 1 9

Ack

LM95213

R/W

Frame 3

Serial Bus Address Byte Frame 4

Data Byte from the LM95213

No Ack

Master

Stop

Master

SMBCLK

SMBDAT

SMBCLK

(Continued)

SMBDAT

(Continued)

A5 A3 A2 A0A6 A4 A1

LM95213

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SNIS147A –MARCH 2007–REVISED MARCH 2013

Figure 15. Serial Bus Write followed by a Repeat Start and Immediate Read

SERIAL INTERFACE RESET

In the event that the SMBus Master is RESET while the LM95213 is transmitting on the SMBDAT line, the

LM95213 must be returned to a known state in the communication protocol. This may be done in one of two

ways:

1. When SMBDAT is LOW, the LM95213 SMBus state machine resets to the SMBus idle state if either

SMBDAT or SMBCLK are held low for more than 35ms (tTIMEOUT). Note that according to SMBus

specification 2.0 all devices are to timeout when either the SMBCLK or SMBDAT lines are held low for 25-

35ms. Therefore, to insure a timeout of all devices on the bus the SMBCLK or SMBDAT lines must be held

low for at least 35ms.

2. When SMBDAT is HIGH, have the master initiate an SMBus start. The LM95213 will respond properly to an

SMBus start condition at any point during the communication. After the start the LM95213 will expect an

SMBus Address address byte.

ONE-SHOT CONVERSION

The One-Shot register is used to initiate a round of conversions and comparisons when the device is in standby

mode, after which the device returns to standby. This is not a data register and it is the write operation that

causes the one-shot conversion. The data written to this address is irrelevant and is not stored. A zero will

always be read from this register. All the channels that are enabled in the Channel Enable Register will be

converted once and the TCRIT1, TCRIT2 and TCRIT3 pins will reflect the comparison results based on this

round of conversion results of the channels that are not masked.

LM95213 Registers

Command register selects which registers will be read from or written to. Data for this register should be

transmitted during the Command Byte of the SMBus write communication.

P7 P6 P5 P4 P3 P2 P1 P0

Command Byte

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P0-P7: Command

Table 8. Register Summary

Byte Write Default

(Hex) (Hex)

Local Temp MSB 0x10 RO SIGN 64 32 16 8 4 2 1 –

Local Temp LSB 0x20 RO 1/2 1/4 1/8 0 0 0 0 0 –

Remote Temp 1 MSB – Signed 0x11 RO SIGN 64 32 16 8 4 2 1 –

Remote Temp 1 LSB – Signed, Digital Filter Off 0 0

0x21 RO 1/2 1/4 1/8 0 0 0 –

Remote Temp 1 LSB – Signed, Digital Filter On 1/16 1/32

Remote Temp 2 MSB – Signed 0x12 RO SIGN 64 32 16 8 4 2 1 –

Remote Temp 2 LSB – Signed, Digital Filter Off 0 0

0x22 RO 1/2 1/4 1/8 0 0 0 –

Remote Temp 2 LSB – Signed, Digital Filter On 1/16 1/32

Remote Temp 1 MSB – Unsigned 0x19 RO 128 64 32 16 8 4 2 1 –

Remote Temp 1 LSB – Unsigned, Digital Filter 0 0

Off 0x29 RO 1/2 1/4 1/8 0 0 0 –

Remote Temp 1 LSB – Unsigned, Digital Filter 1/16 1/32

Remote Temp 2 MSB – Unsigned 0x1A RO 128 64 32 16 8 4 2 1 –

Remote Temp 2 LSB – Unsigned, Digital Filter 0 0

Off 0x2A RO 1/2 1/4 1/8 0 0 0 –

Remote Temp 2 LSB – Unsigned, Digital Filter 1/16 1/32

Remote 1 Offset 0x31 R/W SIGN 32 16 8 4 2 1 1/2 0x00

Remote 2 Offset 0x32 R/W SIGN 32 16 8 4 2 1 1/2 0x00

Configuration 0x03 R/W – STBY – – – – – – 0x00

Conversion Rate 0x04 R/W – – – – – – CR1 CR0 0x02

Channel Conversion Enable 0x05 R/W – – – – – R2CE R1CE LCE 0x1F

Filter Setting 0x06 R/W – – – – R2F1 R2F0 R1F1 R1F0 0x0F

1-shot 0x0F WO – – – – – – – – –

Common Status Register 0x02 RO BUSY NR – – SR4F SR3F SR2F SR1F 0x00

Status 1 (Diode Fault) 0x07 RO – – – – R2DO R2DS R1DO R1DS –

Status 2 (TCRIT1) 0x08 RO – – – – – R2T1 R1T1 LT1 –

Status 3 (TCRIT2) 0x09 RO – – – – – R2T2 R1T2 LT2 –

Status 4 (TCRIT3) 0x0A RO – – – – – R2T3 R1T3 LT3 –

TCRIT1 Mask 0x0C R/W – – – – – R2T1M R1T1M LTM 0x01

TCRIT2 Mask 0x0D R/W – – – – – R2T2M R1T2M LTM 0x00

TCRIT3 Mask 0x0E R/W – – – – – R2T2M R1T2M LTM 0x07

Local Tcrit Limit 0x40 R/W 0 64 32 16 8 4 2 1 0x55

Remote 1 Tcrit-1 Limit 0x41 R/W 128 64 32 16 8 4 2 1 0x6E

Remote 2 Tcrit-1 Limit 0x42 R/W 128 64 32 16 8 4 2 1 0x6E

Remote 1 Tcrit-2 and Tcrit-3 Limit 0x49 R/W 128 64 32 16 8 4 2 1 0x55

Remote 2 Tcrit-2 and Tcrit-3 Limit 0x4A R/W 128 64 32 16 8 4 2 1 0x55

Common Tcrit Hysteresis 0x5A R/W 0 0 0 16 8 4 2 1 0x0A

Manufacturer ID 0xFE RO 0 0 0 0 0 0 0 1 0x01

Revision ID 0xFF RO 1 0 0 0 1 0 1 1 0x8B

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VALUE REGISTERS

For data synchronization purposes, the MSB register should be read first if the user wants to read both MSB and

LSB registers. The LSB will be locked after the MSB is read. The LSB will be unlocked after being read. If the

user reads MSBs consecutively, each time the MSB is read, the LSB associated with that temperature will be

locked in and override the previous LSB value locked-in.

Local Value Registers

Byte Write Default

(Hex) (Hex)

Local Temp MSB 0x10 RO SIGN 64 32 16 8 4 2 1 –

Local Temp LSB 0x20 RO 1/2 1/4 1/8 0 0 0 0 0 –

Bit(s) Bit Name Read/ Description

Write

7 SIGN RO Sign bit The Local temperature MSB value register

range is +127°C to −128°C. The value

6 64 RO bit weight 64°C programmed in this register is used to

5 32 RO bit weight 32°C determine a local temperature error event.

4 16 RO bit weight 16°C

3 8 RO bit weight 8°C

2 4 RO bit weight 4°C

1 2 RO bit weight 2°C

0 1 RO bit weight 1°C

Bit(s) Bit Name Read/ Description

Write

7 1/2 RO bit weight 1/2°C (0.5°C) The Local Limit register range is 0°C to

127°C. The value programmed in this

6 1/4 RO bit weight 1/4°C (0.25°C) register is used to determine a local

5 1/8 RO bit weight 1/8°C (0.125°C) temperature error event.

4-0 0 RO Reserved – will report "0" when read.

Remote Temperature Value Registers with Signed Format

Byte Write Default

(Hex) (Hex)

Remote Temp 1 MSB – Signed 0x11 RO SIGN 64 32 16 8 4 2 1 –

Remote Temp 1 LSB – Signed, Digital 0 0

Filter Off 0x21 RO 1/2 1/8 0 0 0 0 –

Remote Temp 1 LSB – Signed, Digital 1/16 1/32

Filter On

Remote Temp 2 MSB – Signed 0x12 RO SIGN 64 32 16 8 4 2 1 –

Remote Temp 2 LSB – Signed, Digital 0 0

Filter Off 0x22 RO 1/2 1/8 0 0 0 0 –

Remote Temp 2 LSB – Signed, Digital 1/16 1/32

Filter On

The Local temperature MSB value register range is +127°C to −128°C. The value programmed in this register is

used to determine a local temperature error event.

Bit(s) Bit Name Read/ Description

Write

7 SIGN RO Sign bit

6 64 RO bit weight 64°C

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Bit(s) Bit Name Read/ Description

Write

5 32 RO bit weight 32°C

4 16 RO bit weight 16°C

3 8 RO bit weight 8°C

2 4 RO bit weight 4°C

1 2 RO bit weight 2°C

0 1 RO bit weight 1°C

Bit(s) Bit Name Read/ Description

Write

7 1/2 RO bit weight 1/2°C (0.5°C)

6 1/4 RO bit weight 1/4°C (0.25°C)

5 1/8 RO bit weight 1/8°C (0.125°C)

4 0 or 1/16 RO When the digital filter is disabled this bit will always read "0".

When the digital filter is enabled this bit will report 1/16°C (0.0625°C) bit state.

3 0 or 1/32 RO When the digital filter is disabled this bit will always read "0".

When the digital filter is enabled this bit will report 1/32°C (0.03125°C) bit state.

2-0 0 RO Reserved – will report "0" when read.

Remote Temperature Value Registers with Unsigned Format

Byte Write Default

(Hex) (Hex)

Remote Temp 1 MSB – Unsigned 0x19 RO 128 64 32 16 8 4 2 1 –

Remote Temp 1 LSB – Unsigned, 0 0

Digital Filter Off 0x29 RO 1/2 1/8 0 0 0 0 –

Remote Temp 1 LSB – Unsigned, 1/16 1/32

Digital Filter On

Remote Temp 2 MSB – Unsigned 0x1A RO 128 64 32 16 8 4 2 1 –

Remote Temp 2 LSB – Unsigned, 0 0

Digital Filter Off 0x2A RO 1/2 1/8 0 0 0 0 –

Remote Temp 2 LSB – Unsigned, 1/16 1/32

Digital Filter On

Bit(s) Bit Name Read/ Description

Write

7 SIGN RO bit weight 128°C

6 64 RO bit weight 64°C

5 32 RO bit weight 32°C

4 16 RO bit weight 16°C

3 8 RO bit weight 8°C

2 4 RO bit weight 4°C

1 2 RO bit weight 2°C

0 1 RO bit weight 1°C

Bit(s) Bit Name Read/ Description

Write

7 1/2 RO bit weight 1/2°C (0.5°C)

6 1/4 RO bit weight 1/4°C (0.25°C)

5 1/8 RO bit weight 1/8°C (0.125°C)

4 0 or 1/16 RO When the digital filter is disabled this bit will always read "0".

When the digital filter is enabled this bit will report 1/16°C (0.0625°C) bit state.

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Bit(s) Bit Name Read/ Description

Write

3 0 or 1/32 RO When the digital filter is disabled this bit will always read "0".

When the digital filter is enabled this bit will report 1/32°C (0.03125°C) bit state.

2-0 0 RO Reserved – will report "0" when read.

DIODE CONFIGURATION REGISTERS

Remote 1-2 Offset

Byte Write Default

(Hex) (Hex)

Remote 1 Offset 0x31 R/W SIGN 32 16 8 4 2 1 1/2 0x00

Remote 2 Offset 0x32 R/W SIGN 32 16 8 4 2 1 1/2 0x00

Bit(s) Bit Name Read/ Description

Write

7 SIGN R/W Sign bit All registers have 2’s complement format.

The offset range for each remote is

6 32 R/W bit weight 32°C +63.5°C/−64°C. The value programmed in

5 16 R/W bit weight 16°C this register is directly added to the actual

reading of the ADC and the modified number

4 8 R/W bit weight 8°C is reported in the remote value registers.

3 4 R/W bit weight 4°C

2 2 R/W bit weight 2°C

1 1 R/W bit weight 1°C

0 1/2 R/W bit weight 1/2°C (0.5°C)

CONFIGURATION REGISTERS

Main Configuration Register

Byte Write Default

(Hex) (Hex)

Configuration 0x03 R/W – STBY – – – – – – 0x00

Bit(s) Bit Name Read/ Description

Write

7 – RO Reserved will report "0" when read.

6 STBY R/W Software Standby

1 – standby (when in this mode one conversion sequence can be initiated by writing to the

one-shot register)

0 – active/converting

5–0 – RO Reserved – will report "0" when read.

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Conversion Rate Register

Byte Write Default

(Hex) (Hex)

Conversion Rate 0x04 R/W – – – – – – CR1 CR0 0x02

Bit(s) Bit Name Read/ Description

Write

7-2 – RO Reserved – will report "0" when read.

1-0 CR[1:0] R/W Conversion rate control bits modify the time interval for conversion of the channels enabled.

The channels enabled are converted sequentially then standby mode enabled for the

remainder of the time interval.

CR[1:0] Conversion Rate

00 continuous (30 ms to 104 ms)

01 0.364 s

10 1s

11 2.5 s

Channel Conversion Enable

When a conversion is disabled for a particular channel it is skipped. The continuous conversion rate is effected

all other conversion rates are not effected as extra standby time is inserted in order to compensate. See

Conversion Rate Register description.

Byte Write Default

(Hex) (Hex)

Channel Conversion Enable 0x05 R/W – – – – – R2CE R1CE LCE 0x1F

Bit(s) Bit Name Read/ Description

Write

7–3 – RO Reserved – will report "0" when read.

2 R2CE R/W Remote 2 Temperature Conversion Enable

1– Remote 2 temp conversion enabled

0– Remote 2 temp conversion disabled

1 R1CE R/W Remote 1 Temperature Conversion Enable

1– Remote 1 temp conversion enabled

0– Remote 1 temp conversion disabled

0 LCE R/W Local Temperature Conversion Enable

1– Local temp conversion enabled

0– Local temp conversion disabled

Filter Setting

Byte Write Default

(Hex) (Hex)

Filter Setting 0x06 R/W – – – – R2F1 R2F0 R1F1 R1F0 0x0F

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Bit(s) Bit Name Read/ Description

Write

7–4 – RO Reserved – will report "0" when read.

3–2 R2F[1:0] R/W Remote Channel 2 Filter Enable Bits

R2F[1:0] Digital Filter State

00 disable all digital filtering

01 enable basic filter

10 reserved (do not use)

11 enable enhanced filter

1–0 R1F[1:0] R/W Remote Channel 1 Filter Enable

R1F[1:0] Filter State

00 disable all digital filtering

01 enable basic filter

10 reserved (do not use)

11 enable enhanced filter

1-Shot

Byte Write Default

(Hex) (Hex)

1-Shot 0x0F WO – – – – – – – – –

Bit(s) Bit Name Read/ Description

Write

7–0 - WO Writing to this register activates one conversion for all the enabled channels if

the chip is in standby mode (i.e. standby bit = 1). The actual data written does

not matter and is not stored.

STATUS REGISTERS

Common Status Register

Byte Write Default

(Hex) (Hex)

Common Status Register 0x02 RO BUSY NR – – SR4F SR3F SR2F SR1F 0x00

Bit(s) Bit Name Read/ Description

Write

7 BUSY RO Busy bit (device converting)

6 NR RO Not Ready bit (30 ms), indicates power up initialization sequence is in progress

5–4 – RO Reserved – will report "0" when read.

3 SR4F RO Status Register 4 Flag:

1 – indicates that Status Register 4 has at least one bit set

0 – indicates that all of Status Register 4 bits are cleared

2 SR3F RO Status Register 3 Flag:

1 – indicates that Status Register 3 has at least one bit set

0 – indicates that all of Status Register 3 bits are cleared

1 SR2F RO Status Register 2 Flag:

1 – indicates that Status Register 2 has at least one bit set

0 – indicates that all of Status Register 2 bits are cleared

0 SR1F RO Status Register 1 Flag:

1 – indicates that Status Register 1 has at least one bit set

0 – indicates that all of Status Register 1 bits are cleared

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Status 1 Register (Diode Fault)

Status fault bits for open or shorted diode (i.e. Short Fault: D+ shorted to Ground or D-; Open Fault: D+ shorted

to VDD, or floating). During fault conditions the temperature reading is 0 °C if unsigned value registers are read or

–128.000 °C if signed value registers are read.

Byte Write Default

(Hex) (Hex)

Status 1 (Diode Fault) 0x07 RO 0 0 0 0 R2DO R2DS R1DO R1DS –

Bit(s) Bit Name Read/ Description

Write

7-4 – RO Reserved – will report "0" when read.

3 R2DO RO Remote 2 diode open fault status:

1 – indicates that remote 2 diode has an "open" fault

0 – indicates that remote 2 diode does not have an "open" fault

2 R2DS RO Remote 2 diode short fault status:

1 – indicates that remote 2 diode has a "short" fault

0 – indicates that remote 2 diode does not have a "short" fault

1 R1DO RO Remote 1 diode open fault status:

1 – indicates that remote 1 diode has an "open" fault

0 – indicates that remote 1 diode does not have an "open" fault

0 R1DS RO Remote 1 diode short fault status:

1 – indicates that remote 1 diode has a "short" fault

0 – indicates that remote 1 diode does not have a "short" fault

Status 2 (TCRIT1)

Status bits for TCRIT1. When one or more of these bits are set and if not masked the TCRIT1 output will

activate. TCRIT1 will deactivate when all these bits are cleared.

Byte Write Default

(Hex) (Hex)

Status 2 (TCRIT1) 0x08 RO – – – – – R2T1 R1T1 LT1 –

Bit(s) Bit Name Read/ Description

Write

7–3 - RO Reserved – will report "0" when read.

2 R2T1 RO Remote 2 Tcrit-1 Status:

1 – indicates that remote 2 reading is greater than or equal to the value set in Remote 2 Tcrit-1

Limit register

0 – indicates that that remote 2 reading is less than the value set in Remote 2 Tcrit-1 Limit register

minus the Common Hysteresis value

1 R1T1 RO Remote 1 Tcrit-1 Status:

1 – indicates that remote 1 reading is greater than or equal to the value set in Remote 1 Tcrit-1

Limit register

0 – indicates that that remote 1 reading is less than the value set in Remote 1 Tcrit-1 Limit register

minus the Common Hysteresis value

0 LT1 RO Local Tcrit Status:

1 – indicates that local reading is greater than or equal to the value set in Local Tcrit Limit register

0 – indicates that local reading is less than the value set in Local Tcrit Limit register minus the

Common Hysteresis value

Status 3 (TCRIT2)

Status bits for TCRIT2. When one or more of these bits are set and if not masked the TCRIT2 output will

activate. TCRIT2 will deactivate when all these bits are cleared.

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Byte Write Default

(Hex) (Hex)

Status 3 (TCRIT2) 0x09 RO – – – – – R2T2 R1T2 LT2 –

Bit(s) Bit Name Read/ Description

Write

7–3 - RO Reserved – will report "0" when read.

2 R2T2 RO Remote 2 Tcrit-2 Status:

1 – indicates that remote 2 reading is greater than or equal to the value set in Remote 2 Tcrit-2

Limit register

0 – indicates that that remote 2 reading is less than the value set in Remote 2 Tcrit-2 Limit register

minus the Common Hysteresis value

1 R1T2 RO Remote 1 Tcrit-2 Status:

1 – indicates that remote 1 reading is greater than or equal to the value set in Remote 1 Tcrit-2

Limit register

0 – indicates that that remote 1 reading is less than the value set in Remote 1 Tcrit-2 Limit register

minus the Common Hysteresis value

0 LT2 RO Local Tcrit Status:

1 – indicates that local reading is greater than or equal to the value set in Local Tcrit Limit register

0 – indicates that local reading is less than the value set in Local Tcrit Limit register minus the

Common Hysteresis value

Status 4 (TCRIT3)

Status bits for TCRIT3. When one or more of these bits are set and if not masked the TCRIT3 output will

activate. TCRIT3 will deactivate when all these bits are cleared.

Byte Write Default

(Hex) (Hex)

Status 4 (TCRIT3) 0x0A RO – – – – – R2T3 R1T3 LT3 –

Bit(s) Bit Name Read/ Description

Write

7–3 - RO Reserved – will report "0" when read.

2 R2T3 RO Remote 2 Tcrit-2 Status:

1 – indicates that remote 2 reading is greater than or equal to the value set in Remote 2 Tcrit-2

Limit register

0 – indicates that that remote 2 reading is less than the value set in Remote 2 Tcrit-2 Limit register

minus the Common Hysteresis value

1 R1T3 RO Remote 1 Tcrit-2 Status:

1 – indicates that remote 1 reading is greater than or equal to the value set in Remote 1 Tcrit-2

Limit register

0 – indicates that that remote 1 reading is less than the value set in Remote 1 Tcrit-2 Limit register

minus the Common Hysteresis value

0 LT3 RO Local Tcrit Status:

1 – indicates that local reading is greater than or equal to the value set in Local Tcrit Limit register

0 – indicates that local reading is less than the value set in Local Tcrit Limit register minus the

Common Hysteresis value

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MASK REGISTERS

TCRIT1 Mask Register

The mask bits in this register allow control over which error events propagate to the TCRIT1 pin.

Byte Write Default

(Hex) (Hex)

TCRIT1 Mask 0x0C R/W – – – – – R2T1 R1T1 LTM 0x01

M M

Bit(s) Bit Name Read/ Description

Write

7-3 – RO Reserved – will report "0" when read.

2 R2T1M R/W Remote 2 Tcrit-1 Mask:

1 – prevents the remote 2 temperature error event from propagating to the TCRIT1 pin

0 – allows the remote 2 temperature error event to propagate to the TCRIT1 pin

1 R1T1M R/W Remote 1 Tcrit-1 Mask:

1 – prevents the remote 1 temperature error event from propagating to the TCRIT1 pin

0 – allows the remote 1 temperature error event to propagate to the TCRIT1 pin

0 LTM R/W Local Tcrit Mask:

1 – prevents the local temperature error event from propagating to the TCRIT1 pin

0 – allows the local temperature error event to propagate to the TCRIT1 pin

TCRIT2 Mask Registers

Byte Write Default

(Hex) (Hex)

TCRIT2 Mask 0x0D R/W – – – – – R2T2 R1T2 LTM 0x00

M M

Bit(s) Bit Name Read/ Description

Write

7-3 – RO Reserved – will report "0" when read.

2 R2T2M R/W Remote 2 Tcrit-2 Mask:

1 – prevents the remote 2 temperature error event from propagating to the TCRIT2 pin

0 – allows the remote 2 temperature error event to propagate to the TCRIT2 pin

1 R1T2M R/W Remote 1 Tcrit-2 Mask:

1 – prevents the remote 1 temperature error event from propagating to the TCRIT2 pin

0 – allows the remote 1 temperature error event to propagate to the TCRIT2 pin

0 LTM R/W Local Tcrit Mask:

1 – prevents the local temperature error event from propagating to the TCRIT2 pin

0 – allows the local temperature error event to propagate to the TCRIT2 pin

TCRIT3 Mask Register

The mask bits in this register allow control over which error events propagate to the TCRIT3 pin.

Byte Write Default

(Hex) (Hex)

TCRIT3 Mask 0x0E R/W – – – – – R2T2 R1T2 LTM 0x07

M M

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Bit(s) Bit Name Read/ Description

Write

7-3 – RO Reserved – will report "0" when read.

2 R2T2M R/W Remote 2 Tcrit-2 Mask:

1 – prevents the remote 2 temperature error event from propagating to the TCRIT3 pin

0 – allows the remote 2 temperature error event to propagate to the TCRIT3 pin

1 R1T2M R/W Remote 1 Tcrit-2 Mask:

1 – prevents the remote 1 temperature error event from propagating to the TCRIT3 pin

0 – allows the remote 1 temperature error event to propagate to the TCRIT3 pin

0 LTM R/W Local Tcrit Mask:

1 – prevents the local temperature error event from propagating to the TCRIT3 pin

0 – allows the local temperature error event to propagate to the TCRIT3 pin

LIMIT REGISTERS

Local Limit Register

The Local Limit register range is 0°C to 127°C. The value programmed in this register is used to determine a

local temperature error event.

Byte Write Default

(Hex) (Hex)

Local Tcrit Limit 0x40 R/W 0 64 32 16 8 4 2 1 0x55

Bit(s) Bit Name Read/ Description

Write

7 0 R0 Read only bit will always report "0".

6 64 R/W bit weight 64°C

5 32 R/W bit weight 32°C

4 16 R/W bit weight 16°C

3 8 R/W bit weight 8°C

2 4 R/W bit weight 4°C

1 2 R/W bit weight 2°C

0 1 R/W bit weight 1°C

Remote Limit Registers

The range for these registers is 0°C to 255°C.

Byte Write Default

(Hex) (Hex)

Remote 1 Tcrit-1 Limit (used by 0x41 R/W 128 64 32 16 8 4 2 1 0x6E

TCRIT1 error events)

Remote 2 Tcrit-1 Limit (used by 0x42 R/W 128 64 32 16 8 4 2 1 0x6E

TCRIT1 error events)

Remote 1 Tcrit-2 and Tcrit3 Limit (used 0x49 R/W 128 64 32 16 8 4 2 1 0x55

by TCRIT2 and TCRIT3 error events)

Remote 2 Tcrit-2 and Tcrit3 Limit (used 0x4A R/W 128 64 32 16 8 4 2 1 0x55

by TCRIT2 and TCRIT3 error events)

Bit(s) Bit Name Read/ Description

Write

7 128 R/W bit weight 128°C

6 64 R/W bit weight 64°C

5 32 R/W bit weight 32°C

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Bit(s) Bit Name Read/ Description

Write

4 16 R/W bit weight 16°C

3 8 R/W bit weight 8°C

2 4 R/W bit weight 4°C

1 2 R/W bit weight 2°C

0 1 R/W bit weight 1°C

Table 9.

Output Pin Remote 2 Remote 1 Local

TCRIT1 Remote 2 Tcrit-1 Limit Remote 1 Tcrit-1 Limit Local Tcrit Limit

TCRIT2 Remote 2 Tcrit-2 Limit Remote 1 Tcrit-2 Limit Local Tcrit Limit

TCRIT3 Remote 2 Tcrit-2 Limit Remote 1 Tcrit-2 Limit Local Tcrit Limit

Common Tcrit Hysteresis Register

The hysteresis register range is 0°C to 32°C. The value programmed in this register is used to modify all the limit

values for decreasing temperature.

Byte Write Default

(Hex) (Hex)

Common Tcrit Hysteresis 0x5A R/W 0 0 0 16 8 4 2 1 0x0A

Bit(s) Bit Name Read/ Description

Write

7 0 RO Read only bit will always report "0".

6 0 RO Read only bit will always report "0".

5 0 RO Read only bit will always report "0".

4 16 R/W bit weight 16°C

3 8 R/W bit weight 8°C

2 4 R/W bit weight 4°C

1 2 R/W bit weight 2°C

0 1 R/W bit weight 1°C

IDENTIFICATION REGISTERS

Byte Write Default

(Hex) (Hex)

Manufacturer ID 0xFE RO 0 0 0 0 0 0 0 1 0x01

Revision ID 0xFF RO 1 0 0 0 1 0 1 1 0x8B

Applications Hints

The LM95213 can be applied easily in the same way as other integrated-circuit temperature sensors, and its

remote diode sensing capability allows it to be used in new ways as well. It can be soldered to a printed circuit

board, and because the path of best thermal conductivity is between the die and the pins, its temperature will

effectively be that of the printed circuit board lands and traces soldered to the LM95213's pins. This presumes

that the ambient air temperature is almost the same as the surface temperature of the printed circuit board; if the

air temperature is much higher or lower than the surface temperature, the actual temperature of the LM95213 die

will be at an intermediate temperature between the surface and air temperatures. Again, the primary thermal

conduction path is through the leads, so the circuit board temperature will contribute to the die temperature much

more strongly than will the air temperature.

Product Folder Links: LM95213

T = q x 'VBE

x k x ln IF2

IF1

x='ln

BE I

I=Ix

§¹

Sxe

I=Ix

§¹

Sxe

-1

LM95213

www.ti.com

SNIS147A –MARCH 2007–REVISED MARCH 2013

To measure temperature external to the LM95213's die, incorporates remote diode sensing technology. This

diode can be located on the die of a target IC, allowing measurement of the IC's temperature, independent of the

LM95213's temperature. A discrete diode can also be used to sense the temperature of external objects or

ambient air. Remember that a discrete diode's temperature will be affected, and often dominated, by the

temperature of its leads. Most silicon diodes do not lend themselves well to this application. It is recommended

that an MMBT3904 transistor base emitter junction be used with the collector tied to the base.

The LM95213 can measure a diode-connected transistor such as the MMBT3904 or the thermal diode found in

an AMD processor or FPGA. The LM95213 has been optimized to measure the remote thermal diode integrated

in a typical MMBT3904 transistor. The offset register can be used to calibrate for other thermal diodes easily.

The LM9513 deos not include TruTherm™ technology that allows sensing of sub-micron geometry process

thermal diodes. For this applicaiton the LM95233 would be better suitted.

The LM95233 has been specifically optimized to measure the remote thermal diode integrated in a typical Intel

processor on 65nm or 90 nm process or an MMBT3904 transistor. Using the Remote Diode Model Select

65nm or 90nm process or an MMBT3904.

DIODE NON-IDEALITY

Diode Non-Ideality Factor Effect on Accuracy

When a transistor is connected as a diode, the following relationship holds for variables VBE, T and IF:

where

•

• q = 1.6×10−19 Coulombs (the electron charge),

• T = Absolute Temperature in Kelvin

• k = 1.38×10−23 joules/K (Boltzmann's constant),

•ηis the non-ideality factor of the process the diode is manufactured on,

• IS= Saturation Current and is process dependent,

• If= Forward Current through the base-emitter junction

• VBE = Base-Emitter Voltage drop

In the active region, the -1 term is negligible and may be eliminated, yielding the following equation

(2)

In Equation 2,ηand ISare dependant upon the process that was used in the fabrication of the particular diode.

By forcing two currents with a very controlled ratio(IF2 / IF1) and measuring the resulting voltage difference, it is

possible to eliminate the ISterm. Solving for the forward voltage difference yields the relationship:

(3)

Solving Equation 3 for temperature yields:

(4)

Product Folder Links: LM95213

MMBT3904

LM95213

100 pF

PROCESSOR IR

IE = IF

100 pF

D1+

D2+

5D-

Tqx'BE

xln ¸

§I2C

I1C

LM95213

SNIS147A –MARCH 2007–REVISED MARCH 2013

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Equation 4 holds true when a diode connected transistor such as the MMBT3904 is used. When this “diode”

equation is applied to an integrated diode such as a processor transistor with its collector tied to GND as shown

in Figure 16 it will yield a wide non-ideality spread. This wide non-ideality spread is not due to true process

variation but due to the fact that Equation 4 is an approximation.

National invented TruTherm beta cancellation technology uses the transistor equation, Equation 5, which is a

more accurate representation of the topology of the thermal diode found in some sub-micron FPGAs or

processors.

(5)

Figure 16. Thermal Diode Current Paths

TruTherm technology can be found in the LM95233 two channel remote diode sensor that is pin and register

compatible with the LM95213. The LM95213 does not support this technology.

Calculating Total System Accuracy

The voltage seen by the LM95213 also includes the IFRSvoltage drop of the series resistance. The non-ideality

factor, η, is the only other parameter not accounted for and depends on the diode that is used for measurement.

Since ΔVBE is proportional to both ηand T, the variations in ηcannot be distinguished from variations in

temperature. Since the non-ideality factor is not controlled by the temperature sensor, it will directly add to the

inaccuracy of the sensor. For the for Intel processor on 65 nm process, Intel specifies a +4.06%/−0.897%

variation in ηfrom part to part when the processor diode is measured by a circuit that assumes diode equation,

Equation 4, as true. As an example, assume a temperature sensor has an accuracy specification of ±1.0°C at a

temperature of 80°C (353 Kelvin) and the processor diode has a non-ideality variation of +1.19%/−0.27%. The

resulting system accuracy of the processor temperature being sensed will be:

TACC = + 1.0°C + (+4.06% of 353 K) = +15.3 °C

and TACC = - 1.0°C + (−0.89% of 353 K) = −4.1 °C

Product Folder Links: LM95213

TCF = (TCR + 273K)

KS - KPROCESSOR

KS¹

xPCB

62.0

LM95213

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SNIS147A –MARCH 2007–REVISED MARCH 2013

The next error term to be discussed is that due to the series resistance of the thermal diode and printed circuit

board traces. The thermal diode series resistance is specified on most processor data sheets. For Intel

processors in 65 nm process, this is specified at 4.52Ωtypical. The LM95213 accommodates the typical series

resistance of Intel Processor on 65 nm process. The error that is not accounted for is the spread of the

processor's series resistance, that is 2.79Ωto 6.24Ωor ±1.73Ω. The equation to calculate the temperature error

due to series resistance (TER) for the LM95213 is simply:

(6)

Solving Equation 6 for RPCB equal to ±1.73Ωresults in the additional error due to the spread in the series

resistance of ±1.07°C. The spread in error cannot be canceled out, as it would require measuring each individual

thermal diode device. This is quite difficult and impractical in a large volume production environment.

Equation 6 can also be used to calculate the additional error caused by series resistance on the printed circuit

board. Since the variation of the PCB series resistance is minimal, the bulk of the error term is always positive

and can simply be cancelled out by subtracting it from the output readings of the LM95213.

Processor Family Diode Equation ηD, non-ideality Series R,Ω

min typ max

Pentium III CPUID 67h 1 1.0065 1.0125

Pentium III CPUID 68h/PGA370Socket/ 1.0057 1.008 1.0125

Celeron

Pentium 4, 423 pin 0.9933 1.0045 1.0368

Pentium 4, 478 pin 0.9933 1.0045 1.0368

Pentium 4 on 0.13 micron process, 2 - 3.06 1.0011 1.0021 1.0030 3.64

GHz

Pentium 4 on 90 nm process 1.0083 1.011 1.023 3.33

Intel Processor on 65 nm process 1.000 1.009 1.050 4.52

Pentium M (Centrino) 1.00151 1.00220 1.00289 3.06

MMBT3904 1.003

AMD Athlon MP model 6 1.002 1.008 1.016

AMD Athlon 64 1.008 1.008 1.096

AMD Opteron 1.008 1.008 1.096

AMD Sempron 1.00261 0.93

Compensating for Different Non-Ideality

In order to compensate for the errors introduced by non-ideality, the temperature sensor is calibrated for a

particular processor. National Semiconductor temperature sensors are always calibrated to the typical non-

ideality and series resistance of a given processor type. The LM95213 is calibrated for non-ideality factor and

series resistance values supporting the MMBT3904 transistor without the requirement for additional trims. When

a temperature sensor calibrated for a particular processor type is used with a different processor type, additional

errors are introduced.

Temperature errors associated with non-ideality of different processor types may be reduced in a specific

temperature range of concern through use of software calibration. Typical Non-ideality specification differences

cause a gain variation of the transfer function, therefore the center of the temperature range of interest should be

the target temperature for calibration purposes. The following equation can be used to calculate the temperature

correction factor (TCF) required to compensate for a target non-ideality differing from that supported by the

LM95213.

where

•ηS= LM95213 non-ideality for accuracy specification

•ηPROCESSOR = Processor thermal diode typical non-ideality

Product Folder Links: LM95213

TCF = (80 + 273) = -1.75oC

1.003 - 1.008

1.003 ¹

LM95213

SNIS147A –MARCH 2007–REVISED MARCH 2013

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• TCR = center of the temperature range of interest in °C (7)

The correction factor should be directly added to the temperature reading produced by the LM95213. For

example when using the LM95213 to measure a AMD Athlon processor, with a typical non-ideality of 1.008, for a

temperature range of 60 °C to 100 °C the correction factor would calculate to:

(8)

Therefore, 1.75°C should be subtracted from the temperature readings of the LM95213 to compensate for the

differing typical non-ideality target.

PCB LAYOUT FOR MINIMIZING NOISE

Figure 17. Ideal Diode Trace Layout

In a noisy environment, such as a processor mother board, layout considerations are very critical. Noise induced

on traces running between the remote temperature diode sensor and the LM95213 can cause temperature

conversion errors. Keep in mind that the signal level the LM95213 is trying to measure is in microvolts. The

following guidelines should be followed:

1. VDD should be bypassed with a 0.1 µF capacitor in parallel with 100 pF. The 100 pF capacitor should be

placed as close as possible to the power supply pin. A bulk capacitance of approximately 10 µF needs to be

in the near vicinity of the LM95213.

2. A 100 pF diode bypass capacitor is recommended to filter high frequency noise but may not be necessary.

Make sure the traces to the 100 pF capacitor are matched. Place the filter capacitors close to the LM95213

pins.

3. Ideally, the LM95213 should be placed within 10 cm of the Processor diode pins with the traces being as

straight, short and identical as possible. Trace resistance of 1Ωcan cause as much as 0.62°C of error. This

error can be compensated by using simple software offset compensation.

4. Diode traces should be surrounded by a GND guard ring to either side, above and below if possible. This

GND guard should not be between the D+ and D−lines. In the event that noise does couple to the diode

lines it would be ideal if it is coupled common mode. That is equally to the D+ and D−lines.

5. Avoid routing diode traces in close proximity to power supply switching or filtering inductors.

6. Avoid running diode traces close to or parallel to high speed digital and bus lines. Diode traces should be

kept at least 2 cm apart from the high speed digital traces.

7. If it is necessary to cross high speed digital traces, the diode traces and the high speed digital traces should

cross at a 90 degree angle.

8. The ideal place to connect the LM95213's GND pin is as close as possible to the Processors GND

associated with the sense diode.

9. Leakage current between D+ and GND and between D+ and D−should be kept to a minimum. Thirteen

nano-amperes of leakage can cause as much as 0.2°C of error in the diode temperature reading. Keeping

the printed circuit board as clean as possible will minimize leakage current.

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SNIS147A –MARCH 2007–REVISED MARCH 2013

Noise coupling into the digital lines greater than 400 mVp-p (typical hysteresis) and undershoot less than 500 mV

below GND, may prevent successful SMBus communication with the LM95213. SMBus no acknowledge is the

most common symptom, causing unnecessary traffic on the bus. Although the SMBus maximum frequency of

communication is rather low (100 kHz max), care still needs to be taken to ensure proper termination within a

system with multiple parts on the bus and long printed circuit board traces. An RC lowpass filter with a 3 dB

corner frequency of about 40 MHz is included on the LM95213's SMBCLK input. Additional resistance can be

added in series with the SMBDAT and SMBCLK lines to further help filter noise and ringing. Minimize noise

coupling by keeping digital traces out of switching power supply areas as well as ensuring that digital lines

containing high speed data communications cross at right angles to the SMBDAT and SMBCLK lines.

Product Folder Links: LM95213

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REVISION HISTORY

Changes from Original (March 2013) to Revision A Page

• Changed layout of National Data Sheet to TI format .......................................................................................................... 37

Product Folder Links: LM95213

PACKAGE OPTION ADDENDUM

www.ti.com 7-Oct-2013

Addendum-Page 1

PACKAGING INFORMATION

Orderable Device Status

(1)

Package Type Package

Drawing Pins Package

Qty Eco Plan

(2)

Lead/Ball Finish MSL Peak Temp

(3)

Op Temp (°C) Device Marking

(4/5)

Samples

LM95213CISD/NOPB ACTIVE WSON NHL 14 1000 Green (RoHS

& no Sb/Br) CU SN Level-1-260C-UNLIM -40 to 140 95213CI

LM95213CISDX/NOPB ACTIVE WSON NHL 14 4500 Green (RoHS

& no Sb/Br) CU SN Level-1-260C-UNLIM -40 to 140 95213CI

(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.

(4) There may be additional marking, which relates to the logo, the lot trace code information, or the environmental category on the device.

(5) Multiple Device Markings will be inside parentheses. Only one Device Marking contained in parentheses and separated by a "~" will appear on a device. If a line is indented then it is a continuation

of the previous line and the two combined represent the entire Device Marking for that device.

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TAPE AND REEL INFORMATION

*All dimensions are nominal

Device Package

Type Package

Drawing Pins SPQ Reel

Diameter

(mm)

Reel

Width

W1 (mm)

(mm) B0

(mm) K0

(mm) P1

(mm) W

(mm) Pin1

Quadrant

LM95213CISD/NOPB WSON NHL 14 1000 178.0 12.4 4.3 4.3 1.3 8.0 12.0 Q1

LM95213CISDX/NOPB WSON NHL 14 4500 330.0 12.4 4.3 4.3 1.3 8.0 12.0 Q1

PACKAGE MATERIALS INFORMATION

www.ti.com 23-Sep-2013

Pack Materials-Page 1

*All dimensions are nominal

Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm)

LM95213CISD/NOPB WSON NHL 14 1000 210.0 185.0 35.0

LM95213CISDX/NOPB WSON NHL 14 4500 367.0 367.0 35.0

PACKAGE MATERIALS INFORMATION

www.ti.com 23-Sep-2013

Pack Materials-Page 2

MECHANICAL DATA

NHL0014B

www.ti.com

SDA14B (Rev A)

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