Product details

Local sensor accuracy (Max) (+/- C) 1 Type Fan Controller Operating temperature range (C) -40 to 125 Supply voltage (Min) (V) 2.8 Interface type I2C, SMBus Supply voltage (Max) (V) 3.8 Supply current (Max) (uA) 1200 Temp resolution (Max) (bits) 8 Features Tachometer, ALERT Remote channels (#) 2 Addresses 1 Rating Catalog
Local sensor accuracy (Max) (+/- C) 1 Type Fan Controller Operating temperature range (C) -40 to 125 Supply voltage (Min) (V) 2.8 Interface type I2C, SMBus Supply voltage (Max) (V) 3.8 Supply current (Max) (uA) 1200 Temp resolution (Max) (bits) 8 Features Tachometer, ALERT Remote channels (#) 2 Addresses 1 Rating Catalog
TSSOP (PW) 24 34 mm² 7.7 x 4.4
  • Remote diode temperature sensing (2 channels)
  • 8 positive voltage inputs with scaling resistors for monitoring +5 V, +12 V, +3.3 V, +2.5 V, Vccp power supplies directly
  • 2 inputs selectable for fan speed or voltage monitoring
  • 8-bit DAC output for controlling fan speed
  • Chassis Intrusion Detector input
  • WATCHDOG comparison of all monitored values
  • SMBus or I2C Serial Bus interface compatibility
  • VID0-VID4 or IRQ0-IRQ4 monitoring inputs
  • On chip temperature sensor

Key Specifications

  • Voltage Monitoring Error ±2 % (max)
  • External Temperature Error ±4 °C (max)
  • Internal Temperature Error
    • −40 °C to +125 °C ± 3 °C (typ)
  • Supply Voltage Range 2.8 to 3.8 V
  • Supply Current 0.7 mA (typ)
  • ADC and DAC Resolution 8 Bits
  • Temperature Resolution 1.0 °C

All trademarks are the property of their respective owners.

  • Remote diode temperature sensing (2 channels)
  • 8 positive voltage inputs with scaling resistors for monitoring +5 V, +12 V, +3.3 V, +2.5 V, Vccp power supplies directly
  • 2 inputs selectable for fan speed or voltage monitoring
  • 8-bit DAC output for controlling fan speed
  • Chassis Intrusion Detector input
  • WATCHDOG comparison of all monitored values
  • SMBus or I2C Serial Bus interface compatibility
  • VID0-VID4 or IRQ0-IRQ4 monitoring inputs
  • On chip temperature sensor

Key Specifications

  • Voltage Monitoring Error ±2 % (max)
  • External Temperature Error ±4 °C (max)
  • Internal Temperature Error
    • −40 °C to +125 °C ± 3 °C (typ)
  • Supply Voltage Range 2.8 to 3.8 V
  • Supply Current 0.7 mA (typ)
  • ADC and DAC Resolution 8 Bits
  • Temperature Resolution 1.0 °C

All trademarks are the property of their respective owners.

The LM87 is a highly integrated data acquisition system for hardware monitoring of servers, Personal Computers, or virtually any microprocessor-based system. In a PC, the LM87 can be used to monitor power supply voltages, motherboard and processor temperatures, and fan speeds. Actual values for these inputs can be read at any time. Programmable WATCHDOG limits in the LM87 activate a fully programmable and maskable interrupt system with two outputs (INT# and THERM#).

The LM87 has an on-chip digital output temperature sensor with 8-bit resolution as well as the capability of monitoring 2 external diode temperatures to 8-bit resolution, an 8 channel analog input ADC with 8-bit resolution and an 8-bit DAC. A channel on the ADC measures the supply voltage applied to the LM87, nominally 3.3 V. Two of the ADC inputs can be redirected to a counter that can measure the speed of up to 2 fans. A slow speed ΣΔ ADC architecture allows stable measurement of signals in an extremely noisy environment. The DAC, with a 0 to 2.5 V output voltage range, can be used for fan speed control. Additional inputs are provided for Chassis Intrusion detection circuits, and VID monitor inputs. The VID monitor inputs can also be used as IRQ inputs if VID monitoring is not required. The LM87 has a Serial Bus interface that is compatible with SMBus and I2C.

The LM87 is a highly integrated data acquisition system for hardware monitoring of servers, Personal Computers, or virtually any microprocessor-based system. In a PC, the LM87 can be used to monitor power supply voltages, motherboard and processor temperatures, and fan speeds. Actual values for these inputs can be read at any time. Programmable WATCHDOG limits in the LM87 activate a fully programmable and maskable interrupt system with two outputs (INT# and THERM#).

The LM87 has an on-chip digital output temperature sensor with 8-bit resolution as well as the capability of monitoring 2 external diode temperatures to 8-bit resolution, an 8 channel analog input ADC with 8-bit resolution and an 8-bit DAC. A channel on the ADC measures the supply voltage applied to the LM87, nominally 3.3 V. Two of the ADC inputs can be redirected to a counter that can measure the speed of up to 2 fans. A slow speed ΣΔ ADC architecture allows stable measurement of signals in an extremely noisy environment. The DAC, with a 0 to 2.5 V output voltage range, can be used for fan speed control. Additional inputs are provided for Chassis Intrusion detection circuits, and VID monitor inputs. The VID monitor inputs can also be used as IRQ inputs if VID monitoring is not required. The LM87 has a Serial Bus interface that is compatible with SMBus and I2C.

Download

Technical documentation

star = Top documentation for this product selected by TI
No results found. Please clear your search and try again.
View all 7
Type Title Date
* Data sheet LM87 Serial Interface Sys Hardware Monitor w/Remote Diode Temp Sensing datasheet (Rev. J) 22 Mar 2013
Technical article How to choose the right thermistor for your temperature sensing application 13 Feb 2020
Technical article How to enable thermal safety for automotive infotainment and cluster systems 15 Oct 2019
Technical article Driving industrial innovation with small-size sensors 12 Sep 2019
Technical article How to select a temperature sensor probe 18 Feb 2016
Application note Applying I2C-Compatible Temperature Sensors in Systems With Slow Clock Edges (Rev. A) 06 May 2013
White paper Cost Effective Partitioning of IO & Mgm Func in PCs - Intro of SensorPath Tech 01 Jan 2004

Design & development

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

Driver or library

LM87SW-LINUX — Linux Driver for LM87

The Linux driver supports the LM87 System Hardware Monitor. 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

Supported Devices:
  • lm87
Linux Source (...)
Package Pins Download
TSSOP (PW) 24 View options

Ordering & quality

Information included:
  • RoHS
  • REACH
  • Device marking
  • Lead finish/Ball material
  • MSL rating/Peak reflow
  • MTBF/FIT estimates
  • Material content
  • Qualification summary
  • Ongoing reliability monitoring

Recommended products may have parameters, evaluation modules or reference designs related to this TI product.

Support & training

TI E2E™ forums with technical support from TI engineers

Content is provided "as is" by TI and community contributors and does not constitute TI specifications. See terms of use.

If you have questions about quality, packaging or ordering TI products, see TI support. ​​​​​​​​​​​​​​

Videos