TC647VOA Microchip

TC647 PWM Fan Speed Controller with FanSense Technology Features Package Types SOIC/PDIP/MSOP Temperature Proportional Fan Speed for Acoustic Control and Longer Fan Life V Efficient PWM Fan Drive 18 V IN DD 3.0V to 5.5V Supply Range: C27 V F OUT TC647 - Fan Voltage Independent of TC647 V MIN36 FAULT Supply Voltage - Supports any Fan Voltage GND45 SENSE Technology Fault Detection Circuits FanSense Protect Against Fan Failure and Aid System Testing General Description Shutdown Mode forGree Systems The TC647 is a switch mode, fan speed controller for Supports Low Cost NTC/PTC Thermistors use with brushless DC fans. Temperature proportional Space Saving 8-Pin MSOP Package speed control is accomplished using pulse width mod- ulation (PWM). A thermistor (or other voltage output Applications temperature sensor) connected to V furnishes the IN required control voltage of 1.25V to 2.65V (typical) for Power Supplies 0% to 100% PWM duty cycle. Minimum fan speed is Personal Computers set by a simple resistor divider on the V input. An MIN File Servers integrated Start-up Timer ensures reliable motor start- Telecom Equipment up at turn-on, coming out of shutdown mode or UPSs, Power Amps following a transient fault. A logic low applied to V MIN General Purpose Fan Speed Control (Pin 3) causes fan shutdown. The TC647 also features Microchip Technology s pro- Available Tools prietary FanSense technology for increasing system reliability. In normal fan operation, a pulse train is pres- Fan Controller Demonstration Board (TC642DEMO) ent at SENSE (Pin 5). A missing pulse detector moni- Fan Controller Evaluation Kit (TC642EV) tors this pin during fan operation. A stalled, open or unconnected fan causes the TC647 to trigger its Start- up Timer once. If the fault persists, the FAULT output goes low and the device is latched in its shutdown mode. The TC647 is available in the 8-pin plastic DIP, SOIC and MSOP packages and is available in the industrial and extended commercial temperature ranges. 2001-2012 Microchip Technology Inc. DS21447D-page 1TC647 Functional Block Diagram V IN V DD + SHDN + Control V Logic OUT C F 3 x T PWM Timer Clock Generator FAULT Start-up Timer V MIN + V SHDN Missing Pulse Detect. TC647 10k SENSE GND 70mV (typ.) DS21447D-page 2 2001-2012 Microchip Technology Inc. +