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