ADT7475

www.DataSheet4U.com dBCool® Remote Thermal Monitor and Fan Controller ADT7475 FEATURES Controls and monitors up to 4 fans High and low frequency fan drive signal 1 on-chip and 2 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 Meets SMBus 2.0 electrical specifications (fully SMBus 1.1 compliant) Fully RoHS compliant GENERAL DESCRIPTION The ADT7475 dBCool controller is a thermal monitor and multiple PWM fan controller for noise-sensitive or powersensitive applications requiring active system cooling. The ADT7475 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 they operate at the lowest possible speed for minimum acoustic noise. The automatic fan speed control loop optimizes fan speed for a given temperature. The effectiveness of the system’s thermal solution can be monitored using the THERM input. The ADT7475 also provides critical thermal protection to the system using the bidirectional THERM...