GENERAL DESCRIPTION

The ADT7490 is a dBCool® thermal monitor and multiple PWM fan controller for noise-sensitive or power-sensitive applications requiring active system cooling. The ADT7490 includes a local temperature sensor, two remote temperature sensors including series resistance cancellation, and monitors CPU temperature with a PECI interface. The ADT7490 can drive a fan using either a low or high frequency drive signal, and measure and control the speed of up to four fans so they operate at the lowest possible speed for minimum acoustic noise.

FEATURES

Temperature measurement:

1 local on-chip temperature sensor

2 remote temperature sensors

3-current external temperature sensors with series resistance cancellation (SRC)

PECI interface for CPU thermal information and support of up to 4 PECI inputs on one pin

Fan drive and fan speed control

3 high frequency or low frequency PWM outputs for use with 3-wire or 4-wire fans

4 TACH inputs to measure fan speed

OS independent automatic fan speed control based on thermal information

Dynamic TMIN control mode to optimize system acoustics

Default startup at 100 PWM for all fans for robust operation

Bidirectional THERM/SMBALERT pin to flag out-of-limit and overtemperature conditions

GPIO functionality to support extra features

Can be used for loadline setting for voltage regulation, LED control, or other functions

IMON monitoring for CPU current and power information

Footprint and register compatible with ADT7473/ADT7475/ADT7476/ADT7476A family of fan controllers

SMBus interface with addressing capability for up to 3 devices

APPLICATIONS

Personal Computers

Servers