TC664/TC665
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 Over Temperature Detection (TC665) 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 TC664/TC665 devices 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 TC664/TC665 will start driving the fan at a
default duty cycle of 39.33%. See Section 4.3, "Fan
Startup", for more details). Applications Personal Computers & Servers
LCD Projectors
Datacom & Telecom Equipment
Fan Trays
File Servers
Workstations
General Purpose Fan Speed Control An over-temperature condition is indicated when the …