ADT7490 Datasheet, PDF (1/76 Pages) Analog Devices – dBCool Remote Thermal Monitor and Fan Controller with PECI Interface

dBCool Remote Thermal Monitor and Fan
Controller with PECI Interface
ADT7490
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
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.
The automatic fan speed control loop optimizes fan speed
for a given temperature using the PECI, remote, or local
temperature information. The effectiveness of the system’s
thermal solution can be monitored using the THERM input.
The ADT7490 also provides critical thermal protection to
the system using the bidirectional THERM/SMBALERT pin as
an output to prevent system or component overheating.
Rev. 0
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