說明

• PWM Fan Controller - WISHBONE Compatible Reference Design. Pulse-width modulation (PWM) is a popular technique to control analog circuitry digitally. PWM uses a rectangular pulse wave whose pulse width is modulated resulting in the variation of the average value of the waveform. In this PWM implementation, current flow through a MOSFET circuit controls the amount of power sent to a fan load. This reference design implements a PWM fan control using a PLD and a MOSFET circuit to provide the speed control of a simple 2-pin fan. When using a 3-pin fan and a PLD, the sense signal from the fan completes the feedback loop