Interfacing Microchip’s Fan Speed Controllers to a SPI
Microchip's TC642, TC643, and TC646 are the world's first integrated circuits dedicated for controlling and monitoring fan speed. The new family of fan speed controllers modulate fan speed to compensate for changes in system temperature. This means the fan runs at full speed only when necessary, significantly extending fan life. In addition to increased fan life, fan speed is controlled by PWM control circuitry that is more efficient than conventional linear techniques. The ICs provide other features such as fan current limiting, minimum speed control, auto shutdown, and speed, fault, and over-temperature indication.
AN51, Fan Speed Controller, SPI Port, TC642, TC643, TC646