TC642DEMO

PWM风扇速度控制器， FanSense⑩技术 PWM Fan Speed Controller with FanSense⑩ Technology

General Description

The TC642 is a switch mode fan speed controller for use with brushless DC fans. Temperature proportional speed control is accomplished using pulse width mod ulation 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. Minimum fan

speed is set by a simple resistor divider on the VMIN input. An integrated Start-up Timer ensures reliable motor start-up at turn-on, coming out of shutdown mode or following a transient fault. A logic low applied to VMINPin 3 causes fan shutdown.

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 TC642 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

• Personal Computers

• File Servers

• Telecom Equipment

• UPSs, Power Amps, etc.

• General Purpose Fan Speed Control

Available Tools

• Fan Controller Demonstration Board

• Fan Controller Evaluation Kit TC642EV