The Microchip TC642 is a PWM fan speed controller with FanSense fault detection, supporting 3.0‑5.5 V supply, 30 Hz PWM, and multiple package options.
The TC642 PWM fan speed controller provides proportional fan speed control based on temperature, reducing noise and extending fan life. It features high‑efficiency PWM drive, FanSense™ fault detection, a shutdown mode for power saving, and support for low‑cost NTC/PTC thermistors. The device operates from a 3.0 V to 5.5 V supply and is available in PDIP, SOIC, and MSOP 8‑pin packages.
Typical applications include power supplies, PCs, servers, telecom equipment, UPS units, and audio amplifiers. The datasheet details electrical characteristics, pin functions, the internal algorithm flow, and example circuits for temperature sensing and fan drive.
| Supply voltage range | 3.0 V – 5.5 V |
|---|---|
| Operating temperature range | -40 °C – +125 °C |
| PWM frequency (recommended) | 30 Hz (CF = 1 µF) |
| Normal operating current (IDD) | 0.5 mA – 1.0 mA |
| Shutdown mode current (IDD) | 2 µA – 5 µA |
The device operates from a supply voltage between 3.0 V and 5.5 V.
FanSense™ monitors pulses on the SENSE pin; if pulses are missing, the FAULT output goes low and the device locks in shutdown mode.
Pull the VMIN pin low below the VSHDN threshold (approximately VDD × 0.13) to enter shutdown mode.
A PWM frequency of 30 Hz is recommended, using a 1 µF capacitor on the CF pin.