TC655

TC654/TC655 Dual SMBus™ PWM Fan Speed Controllers With Fan Fault Detection Features: Temperature Proportional Fan Speed for Reduced Acoustic Noise and Longer Fan Life FanSense™ Protects against Fan Failure and Eliminates the Need for 3-wire Fans Overtemperature Detection (TC655) Efficient PWM Fan Drive Provides RPM Data 2-Wire SMBus™-Compatible Interface Supports Any Fan Voltage Software Controlled Shutdown Mode for "Green" Systems Supports Low-Cost NTC/PTC Thermistors Space Saving 10-Pin MSOP Package Temperature Range: -40°C to +85ºC Applications: Personal Computers and Servers LCD Projectors Datacom and Telecom Equipment Fan Trays File Servers Workstations General Purpose Fan Speed Control Package Type 10-Pin MSOP VIN 1 CF 2 SCLK 3 SDA 4 GND 5 TC654 TC655 10 VDD 9 VOUT 8 SENSE1 7 SENSE2 6 FAULT Description: The TC654 and TC655 are PWM mode fan speed controllers with FanSense technology for use with brushless DC fans. These devices implement temperature proportional fan speed control which lowers acoustic fan noise and increases fan life. The voltage at VIN (Pin 1) represents temperature and is typically provided by an external thermistor or voltage output temperature sensor. The PWM output (VOUT) is adjusted between 30% and 100%, based on the voltage at VIN. The PWM duty cycle can also be programmed via SMBus to allow fan speed control without the need for an external thermistor. If VIN is not connected, the TC654/TC655 will start d...