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LM99

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Remote and Local Temperature Sensor with TruTherm Technology and SMBus Interface

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Data sheet

LM99

ACTIVE
Data sheet Order now

Product details

Local sensor accuracy (max) 3 Type Remote Operating temperature range (°C) 0 to 85 Supply voltage (min) (V) 2.85 Interface type I2C, SMBus Supply voltage (max) (V) 3.6 Features ALERT, One-shot conversion Supply current (max) (µA) 1700 Temp resolution (max) (bps) 8 Remote channels (#) 1 Addresses 2 Rating Catalog
Local sensor accuracy (max) 3 Type Remote Operating temperature range (°C) 0 to 85 Supply voltage (min) (V) 2.85 Interface type I2C, SMBus Supply voltage (max) (V) 3.6 Features ALERT, One-shot conversion Supply current (max) (µA) 1700 Temp resolution (max) (bps) 8 Remote channels (#) 1 Addresses 2 Rating Catalog
VSSOP (DGK) 8 14.7 mm² 3 x 4.9
  • Accurately Senses the Temperature of Remote Diodes
  • Offset Register Allows Use of a Variety of Thermal Diodes
  • On-board Local Temperature Sensing
  • 10 Bit Plus Sign Remote Diode Temperature Data Format, 0.125 °C Resolution
  • T_CRIT_A Output Useful for System Shutdown
  • ALERT Output Supports SMBus 2.0 Protocol
  • SMBus 2.0 Compatible Interface, Supports TIMEOUT
  • 8-Pin VSSOP Package

Key Specifications

  • Supply Voltage 3.0 V to 3.6 V
  • Supply Current 0.8 mA (typ)
  • Local Temp Accuracy
    (Includes Quantization error)
    • TA = 25°C to 125°C ±3.0°C (Max)
  • Remote Diode Temp Accuracy
    (Includes Quantization Error)
    • TA = 30°C to 50°C, TD = 120°C to 140°C ±1.0°C (Max)
    • TA = 0°C to 85°C, TD = 25°C to 140°C ±3.0°C (Max)

All trademarks are the property of their respective owners.

  • Accurately Senses the Temperature of Remote Diodes
  • Offset Register Allows Use of a Variety of Thermal Diodes
  • On-board Local Temperature Sensing
  • 10 Bit Plus Sign Remote Diode Temperature Data Format, 0.125 °C Resolution
  • T_CRIT_A Output Useful for System Shutdown
  • ALERT Output Supports SMBus 2.0 Protocol
  • SMBus 2.0 Compatible Interface, Supports TIMEOUT
  • 8-Pin VSSOP Package

Key Specifications

  • Supply Voltage 3.0 V to 3.6 V
  • Supply Current 0.8 mA (typ)
  • Local Temp Accuracy
    (Includes Quantization error)
    • TA = 25°C to 125°C ±3.0°C (Max)
  • Remote Diode Temp Accuracy
    (Includes Quantization Error)
    • TA = 30°C to 50°C, TD = 120°C to 140°C ±1.0°C (Max)
    • TA = 0°C to 85°C, TD = 25°C to 140°C ±3.0°C (Max)

All trademarks are the property of their respective owners.

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:

  TACTUAL DIODE JUNCTION = TLM99 + 16°C

The local temperature reading requires no offset.

The LM99 has an Offset Register which provides a means for precise matching to various thermal diodes.

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.

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:

  TACTUAL DIODE JUNCTION = TLM99 + 16°C

The local temperature reading requires no offset.

The LM99 has an Offset Register which provides a means for precise matching to various thermal diodes.

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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Technical documentation

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* Data sheet LM99 Accurate High Temp, Remote Diode Temp Sensor w/Two-Wire Interface datasheet (Rev. D) 22 Mar 2013
User guide LM86, LM89, LM89-1, LM90, LM99, LM99-1 Evaluation Board User’s Guide 29 Feb 2012

Design & development

For additional terms or required resources, click any title below to view the detail page where available.

Driver or library

LM90SW-LINUX — Linux Driver for LM90

The Linux driver supports the LM90 series of Remote and Local Temp Sensors. The Linux driver supports communication through the I2C bus and interfaces with the Hardware Monitoring sub-system.

 

Linux Mainline Status

Available in Linux Main line: Yes
Available through git.ti.com: N/A

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Support software

DIGITALTEMPSENSORSEVM-SW — Eval Board Software for Hardware Monitors and Digital Temp Sensors

Evaluation Board Software for Hardware Monitors and Digital Temperature Sensors
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Support software

SENSOREVAL — Eval Board Software For Hardware Monitors And Digital Temperature Sensors

SensorEval
SensorEval software supports the latest TI temperature sensor and hardware monitor evaluation boards via USB interface. It also allows access to sensors mounted directly on motherboards that support Intel chip sets.

  • Download SensorEval Software and Manual
  • Windows XP support is offered for (...)
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Supported products & hardware
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