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 1 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