GENERAL DESCRIPTION

The ADT7476A dBCOOL controller is a thermal monitor and multiple PWM fan controller for noise-sensitive or power sensitive applications requiring active system cooling. The ADT7476A can drive a fan using either a low or high frequency drive signal and can monitor the temperature of up to two remote sensor diodes plus its own internal temperature. The part also measures and controls the speed of up to four fans, so the fans operate at the lowest possible speed for minimum acoustic noise.

FEATURES

Monitors up to five voltages

Improved TACH and PWM performance

Controls and monitors up to four fans

High and low frequency fan drive signal

One on-chip and two remote temperature sensors

Extended temperature measurement range up to 191°C

Automatic fan speed control mode controls system cooling based on measured temperature

Enhanced acoustic mode dramatically reduces user perception of changing fan speeds

Thermal protection feature via THERM output

Monitors performance impact of Intel® Pentium® 4 processor

Thermal control circuit via THERM input

3-wire and 4-wire fan speed measurement

Limit comparison of all monitored values

5 V support on all TACH and PWM channels

Meets SMBus 2.0 electrical specifications