TC654/TC655
Dual SMBusв„ў PWM Fan Speed Controllers With
Fan Fault Detection
Features: Description: Temperature Proportional Fan Speed for Reduced
Acoustic Noise and Longer Fan Life FanSenseв„ў Protects against Fan Failure and
Eliminates the Need for 3-wire Fans Overtemperature Detection (TC655) Efficient PWM Fan Drive Provides RPM Data 2-Wire SMBusв„ў-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: -40В°C to +85ВєC 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 driving the fan at a default duty
cycle of 39.33%. See Section 4.3 “Fan Start-up” for
more details. Applications: Personal Computers and Servers
LCD Projectors
Datacom and Telecom Equipment
Fan Trays
File Servers
Workstations
General Purpose Fan Speed Control Package Type …