The MCP9903/MCP9904 are high accuracy, low cost, System Management Bus (SMBus) temperature sensors. Advanced features such as Resistance Error Correction (REC), Beta Compensation (to support CPU diodes requiring the BJT/transistor model including 45nm and advanced processors) and automatic diode type detection combine to provide a robust solution for complex environmental monitoring applications.

The MCP9903 monitors three temperature channels and the MCP9904 monitors four temperature channels. It provides ±1oC accuracy for both external and internal diode temperatures.

Resistance Error Correction automatically eliminates the temperature error caused by series resistance allowing greater flexibility in routing thermal diodes. Beta Compensation eliminates temperature errors caused by low, variable beta transistors common in today's fine geometry processors. The automatic beta detection feature monitors each external diode/transistor and determines the optimum sensor settings for accurate temperature measurements regardless of processor technology. This frees the user from providing unique sensor configurations for each temperature monitoring application. These advanced features plus ±1°C measurement accuracy provide a low-cost, highly flexible and accurate solution for critical temperature monitoring applications.

Features

  Programmable SMBus Address

  Support for diodes requiring the BJT/transistor model

  supports 45nm and advanced CPU thermal diodes

  Automatically determines external diode type and optimal settings

  Resistance Error Correction

  Up to 3 External Temperature Monitors

  ±1°C max accuracy (-40°C < TREMOTE < 125°C)

  0.125°C resolution

  Supports up to 2.2nF diode filter capacitor

  Anti-parallel diodes for extra diode support

  Internal Temperature Monitor

  ±1°C accuracy (-40°C < TAMBIENT < 65°C)

  ±0.125°C resolution

  3.3V Supply Voltage

  Programmable temperature limits for ALERT#

  Available in these RoHS compliant packages

  10-pin MSOP

Applications

  Remote Radio Unit (RRU)

  Basestation

  Refrigeration

  Industrial

  Embedded applications