TC646VUA Datasheet PDF - Microchip

●General Description

●The TC646 is a switch mode, fan speed controller for use with brushless DC fans. Temperature proportional speed control is accomplished using pulse width modulation (PWM). A thermistor (or other voltage output temperature sensor) connected to the VIN input furnishes the required control voltage of 1.25V to 2.65V (typical) for 0% to 100% PWM duty cycle. The TC646

●automatically suspends fan operation when measured temperature (VIN) is below a user programmed minimum setting (VAS). An integrated Start-up Timer ensures reliable motor start-up at turn-on, coming out of shutdown mode, auto-shutdown mode or following a transient fault.

●Features

●• Temperature Proportional Fan Speed for Acoustic Control and Longer Fan Life

●• Efficient PWM Fan Drive

●• 3.0V to 5.5V Supply Range:

●\- Fan Voltage Independent of TC646 Supply Voltage

●\- Supports any Fan Voltage

●• FanSense™Fault Detection Circuits Protect Against Fan Failure and Aid System Testing

●• Shutdown Mode for "Green" Systems

●• Supports Low Cost NTC/PTC Thermistors

●• Space Saving 8-Pin MSOP Package

●• Over-temperature Indication

●Applications

●• Power Supplies

●• Computers

●• File Servers

●• Portable Computers

●• Telecom Equipment

●• UPS, Power Amps

●• General Purpose Fan Speed Control