TC642
PWM Fan Speed Controller with FanSenseв„ў Technology
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 FanSenseв„ў 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 (TC642DEMO) Fan Controller Evaluation Kit (TC642EV) Package Types
SOIC/PDIP/MSOP
VIN 1 CF 2 VMIN
GND 8 VDD 7 VOUT 3 6 FAULT 4 5 SENSE TC642 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 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. Minimum fan
speed is set by a simple resistor divider on the VMIN
input. An integrated Start-up Timer ensures reliable …
