Rainbow Electronics LM99 User Manual

LM99

1˚C Accurate, High Temperature, Remote Diode

Temperature Sensor with Two-Wire Interface

General Description

The LM99 is an 11-bit remote diode temperature sensor with a 2-wire System Management Bus (SMBus) serial interface. The LM99 accurately measures: (1) its own temperature and (2) the temperature of a remote diode-connected transistor such as the 2N3904 or a thermal diode commonly found on Graphics Processor Units (GPU), Computer Processor Units (CPU or other ASICs. The LM99 remote diode temperature sensor shifts the temperature from the remote sensor down 16˚C and operates on that shifted temperature:

ACTUAL DIODE JUNCTION

The local temperature reading requires no offset. The LM99 has an Offset Register which provides a means

for precise matching to various thermal diodes. Contact hardware.monitor

The LM99 and LM99-1 have the same functions but different SMBus slave addresses. This allows for one of each to be on the same bus at the same time.

Activation of the ALERT output occurs when any temperature goes outside a preprogrammed window set by the HIGH and LOW temperature limit registers or exceeds the T_CRIT temperature limit. Activation of the T_CRIT_A occurs when any temperature exceeds the T_CRIT programmed limit.

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LM99

+ 16˚C

Features

n Accurately senses the temperature of remote diodes n Offset register allows use of a variety of thermal diodes

n On-board local temperature sensing n 10 bit plus sign remote diode temperature data format,

0.125 ˚C resolution

n T_CRIT_A output useful for system shutdown n ALERT output supports SMBus 2.0 protocol n SMBus 2.0 compatible interface, supports TIMEOUT n 8-pin MSOP package

Key Specifications

Supply Voltage 3.0 V to 3.6 V

Supply Current 0.8 mA (typ)

Local Temp Accuracy (includes quantization error)

= 25˚C to 125˚C

Remote Diode Temp Accuracy (includes quantization

error)

= 30˚C to 50˚C, TD= 120˚C to 140˚C

= 0˚C to 85˚C, TD= 25˚C to 140˚C

Applications

n Graphics Processor Thermal Management n Computer Processor Thermal Management n Electronic Test Equipment n Office Electronics

July 2003

3.0˚C (max)

1.0˚C (max)

3.0˚C (max)

Interface

LM99

1˚C Accurate, High Temperature, Remote Diode Temperature Sensor with Two-Wire

Simplified Block Diagram

20053801

NVIDIA®is a registered trademark of NVIDIA Corporation.

™

GeForce

is a trademark of NVIDIA Corporation.

Intel

and Pentium®are registered trademarks of Intel Corporation.

Connection Diagram

LM99

MSOP-8

TOP VIEW

20053802

Ordering Information

Part Number

LM99CIMM T17C

LM99-1CIMM T20C

LM99CIMMX T17C

LM99-1CIMMX T20C

Package

Marking

NS Package

Number

MUA08A

(MSOP-8)

MUA08A

(MSOP-8)

MUA08A

(MSOP-8)

MUA08A

(MSOP-8)

Pin Descriptions

Label Pin

D+ 2 Diode Current Source

D− 3 Diode Return Current Sink

T_CRIT_A

GND 5 Power Supply Ground Ground

ALERT

SMBData 7

SMBCLK 8 SMBus Input From Controller, Pull-Up Resistor

1 Positive Supply Voltage Input

T_CRIT Alarm Output, Open-Drain, Active-Low

Interrupt Output, Open-Drain, Active-Low

SMBus Bi-Directional Data Line, Open-Drain Output

Function Typical Connection

DC Voltage from 3.0 V to 3.6 V. V with a 0.1 µF capacitor in parallel with 100 pF to ground. 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 vicinity of the LM99

To Diode Anode. Connected to the collector and base of the remote discrete diode-connected transistor. Connect a

2.2 nF capacitor between pins 2 and 3.

To Diode Cathode. Connects to the emitter of the remote diode-connected transistor. Connect a 2.2 nF capacitor between pins 2 and 3.

Pull-Up Resistor, Controller Interrupt or Power Supply Shutdown Control

Pull-Up Resistor, Controller Interrupt or Alert Line

From and to Controller, Pull-Up Resistor

Transport

Media

1000 Units on Tape and Reel

3500 Units on Tape and Reel

should be bypassed

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Typical Application

LM99

20053803

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Absolute Maximum Ratings (Note 1)

LM99

Supply Voltage −0.3 V to 6.0 V

Voltage at SMBData, SMBCLK, ALERT, T_CRIT_A

Voltage at Other Pins −0.3 V to

D− Input Current

Input Current at All Other Pins (Note 2)

Package Input Current (Note 2)

SMBData, ALERT, T_CRIT_A Output Sink Current 10 mA

Storage Temperature −65˚C to

−0.5 V to 6.0 V

+ 0.3 V)

1mA

5mA

30 mA

+150˚C

MSOP-8 Packages (Note 3)

Vapor Phase (60 seconds) 215˚C

Infrared (15 seconds) 220˚C

ESD Susceptibility (Note 4)

Human Body Model 2000 V

Machine Model 200 V

Operating Ratings

(Notes 1, 5)

Operating Temperature Range 0˚C to +125˚C

Electrical Characteristics Temperature Range T

LM99 0˚C ≤ TA≤ +85˚C

Supply Voltage Range (V

) +3.0 V to +3.6 V

MIN

Soldering Information, Lead Temperature

Temperature-to-Digital Converter Characteristics

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

Temperature Error Using Local Diode T

Temperature Error Using Remote Diode Connected Transistor (TDis the Remote Diode Junction Temperature)

D=TLM99

Remote Diode Measurement Resolution 11 Bits

Local Diode Measurement Resolution 8 Bits

Conversion Time of All Temperatures at the Fastest Setting

Quiescent Current (Note 9) SMBus Inactive, 16 Hz

D− Source Voltage 0.7 V

Diode Source Current (V

ALERT and T_CRIT_A Output Saturation Voltage

Power-On-Reset (POR) Threshold Measure on VDDinput, falling

Local and Remote HIGH Default Temperature settings

Local and Remote LOW Default Temperature settings

Local T_CRIT Default Temperature Setting (Note 11) +85 ˚C

Remote T_CRIT Default Temperature Setting (Note 11) Add 16˚C for 126˚C

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

MAX

Parameter Conditions Typical Limits Units

(Note 6) (Note 7) (Limit)

+ 16˚C

= +25˚C to +125˚C, (Note 8)

= +30˚C to +50˚C and TD=

+120˚C to +140˚C

= +0˚C to +85˚C and TD=

+25˚C to +140˚C

3 ˚C (max)

1 ˚C (max)

0.125 ˚C

1˚C

(Note 10) 31.25 34.4 ms (max)

0.8 1.7 mA (max)

conversion rate

Shutdown 315 µA

D+−VD−

level

) = + 0.65 V; high

160 315 µA (max)

110 µA (min)

Low level 13 20 µA (max)

7 µA (min)

= 6.0 mA 0.4

OUT

2.4

edge

(Note 11) Add 16˚C for true

+70 ˚C

1.8

Remote Temperature.

(Note 11) Add 16˚C for true

0˚C

Remote Temperature.

+110 ˚C

true Remote T_CRIT Setting

≤ TA≤ T

˚C (max)

V (max)

V (min)

MAX

MIN

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Logic Electrical Characteristics

DIGITAL DC CHARACTERISTICS Unless otherwise noted, these specifications apply for VDD= +3.0 to 3.6 Vdc. Boldface

to T

limits apply for T

A=TJ=TMIN

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

MAX

Symbol Parameter Conditions Typical Limits Units

(Note 6) (Note 7) (Limit)

SMBData, SMBCLK INPUTS

IN(1)

IN(0)

IN(HYST)

Logical “1” Input Voltage 2.1 V (min)

Logical “0”Input Voltage 0.8 V (max)

SMBData and SMBCLK Digital

400 mV

Input Hysteresis

IN(1)

IN(0)

Logical “1” Input Current VIN=V

0.005

Logical “0” Input Current VIN= 0 V −0.005

Input Capacitance 5 pF

10 µA (max)

ALL DIGITAL OUTPUTS

High Level Output Current VOH=V

SMBus Low Level Output Voltage IOL=4mA

=6mA

10 µA (max)

0.4

V (max)

0.6

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

to T

pF. Boldface limits apply for T

A=TJ=TMIN

ing characteristics of the LM99 fully meet or exceed the published specifications of the SMBus version 2.0. The following parameters are the timing relationships between SMBCLK and SMBData signals related to the LM99. They adhere to but are not necessarily the SMBus bus specifications.

Symbol Parameter Conditions Typical Limits Units

SMB

LOW

HIGH

R,SMB

F,SMB

TIMEOUT

SMBus Clock Frequency 100

SMBus Clock Low Time from V

SMBus Clock High Time from V

SMBus Rise Time (Note 12) 1 µs (max)

SMBus Fall Time (Note 13) 0.3 µs (max)

Output Fall Time CL= 400 pF,

SMBData and SMBCLK Time Low for Reset of Serial Interface (Note 14)

SU;DAT

HD;DAT

HD;STA

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

Data Out Stable after SMBCLK Low 300

Start Condition SMBData Low to SMBCLK Low (Start condition hold before the first clock falling edge)

SU;STO

Stop Condition SMBCLK High to SMBData Low (Stop Condition Setup)

SU;STA

SMBus Repeated Start-Condition Setup Time, SMBCLK High to SMBData Low

BUF

SMBus Free Time Between Stop and Start Conditions

; all other limits TA=TJ= +25˚C, unless otherwise noted. The switch-

MAX

(Note 6) (Note 7) (Limit)

kHz (max)

max to

IN(0)

max

IN(0)

IN(1)

min to V

min 4.0 µs (min)

IN(1)

4.7 25

kHz (min)

ms (max)

250 ns (max)

= 3 mA, (Note 13)

25 35

ms (max)

900

100 ns (min)

0.6 µs (min)

1.3 µs (min)

µs (min)

ms (min)

ns (min)

ns (max)

LM99

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SMBus Communication

LM99

Note 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.

Note 2: When the input voltage (V

Parasitic components and or ESD protection circuitry are shown in the figure below for the LM99’s pins. The nominal breakdown voltage of D3 is 6.5 V. Care should be taken not to forward bias the parasitic diode, D1, present on pins: D+, D−. Doing so by more than 50 mV may corrupt a temperature measurement.

) at any pin exceeds the power supplies (V

GND or V

VDD), the current at that pin should be limited to 5 mA.

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Pin Name PIN

D1 D2 D3 D4 D5 D6 D7 R1 SNP ESD CLAMP

1 x

D+ 2 xx xxx x

D− 3 xx xxx x

T_CRIT_A

ALERT

4xxx

6xxx

SMBData 7 x x x

SMBCLK 8 x

Note: An “x” indicates that the diode exists.

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FIGURE 1. ESD Protection Input Structure

Note 3: See the URL ”http://www.national.com/packaging/“ for other recommendations and methods of soldering surface mount devices.

Note 4: Human body model, 100 pF discharged through a 1.5 kΩ resistor. Machine model, 200 pF discharged directly into each pin.

Note 5: Thermal resistance junction-to-ambient when attached to a printed circuit board with 2 oz. foil:

– MSOP-8 = 210˚C/W

Note 6: Typicals are at T

Note 7: Limits are guaranteed to National’s AOQL (Average Outgoing Quality Level).

Note 8: 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 LM99 and the thermal resistance. See (Note 5) for the thermal resistance to be used in the self-heating calculation.

Note 9: Quiescent current will not increase substantially with an SMBus.

Note 10: This specification is provided only to indicate how often temperature data is updated. The LM99 can be read at any time without regard to conversion state

(and will yield last conversion result).

Note 11: Default values set at power up.

Note 12: The output rise time is measured from (V

Note 13: The output fall time is measured from (V

Note 14: Holding the SMBData and/or SMBCLK lines Low for a time interval greater than t

SMBData and SMBCLK pins to a high impedance state.

= 25˚C and represent most likely parametric norm.

max + 0.15 V) to (V

IN(0)

min - 0.15 V) to (V

IN(1)

min − 0.15 V).

IN(1)

min + 0.15 V).

IN(1)

will reset the LM99’s SMBus state machine, therefore setting

TIMEOUT

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