TC648BEOA

The TC648BEOA is a PWM Fan Speed Controller with auto-shutdown, fan restart and FanSense™ technology for fault detection. It is switch-mode fan speed controller that incorporates a new fan auto-restart function. Temperature-proportional speed control is accomplished using pulse width modulation. A thermistor connected to the VIN input supplies the required control voltage of 1.2 to 2.6V typical for 0 to 100% PWM duty cycle. The auto-shutdown threshold/temperature is set by a simple resistor divider on the VAS input. An integrated Start-Up Timer ensures reliable fan motor start-up at turn-ON, coming out of shutdown mode, auto-shutdown mode or following a transient fault. A logic low applied to VIN causes fan shutdown. In normal fan operation, a pulse train is present at SENSE. A missing-pulse detector monitors this pin during fan operation. A stalled, open or unconnected fan causes this device to turn the VOUT output on full. If the fan fault persists, the FAULT output goes low.

• Temperature proportional fan speed for acoustic noise reduction and longer fan life
• Efficient PWM fan drive
• FanSense™ Fault detection circuit protects against fan failure and aids system testing
• Automatic shutdown mode for green systems
• Supports NTC/PTC thermistors
• Fan auto-restart