GENERAL DESCRIPTION

The ADT7467 dBCOOLTM controller is a thermal monitor and multiple PWM fan controller for noise-sensitive or power sensitive applications requiring active system cooling. The ADT7467 can drive a fan using either a low or high frequency drive signal, monitor the temperature of up to two remote sensor diodes plus its own internal temperature, and measure and control the speed of up to four fans, so that they operate at the lowest possible speed for minimum acoustic noise.

The automatic fan speed control loop optimizes fan speed for a given temperature. A unique dynamic TMIN control mode enables the system thermals/acoustics to be intelligently managed. The effectiveness of the systems thermal solution can be monitored using the THERM input. The ADT7467 also provides critical thermal protection to the system using the bidirectional THERM pin as an output to prevent system or component overheating.

FEATURES

Controls and monitors up to 4 fans

High and low frequency fan drive signal

1 on-chip and 2 remote temperature sensors

Series resistance cancellation on the remote channel

Extended temperature measurement range, up to 191°C

Dynamic TMIN control mode optimizes system acoustics intelligently

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

2-wire, 3-wire, and 4-wire fan speed measurement

Limit comparison of all monitored values

Meets SMBus 2.0 electrical specifications (fully SMBus 1.1 compliant)