AN2137 - PWM Controlled Fan for MEC140x/MEC141x/MEC142x
Tom Tse / Greg VanWesten
Pulse Width Modulation (PWM) modules, which produce basically digital waveforms, can be used in many applications as a more efficient and lower power alternative to the traditional 8 bit Digital-to-Analog (D/A) converters using only two inexpensive filter components. A wide variety of microcontroller applications that exist today are better served by utilizing a PWM generated analog output as opposed to an 8 bit D/A converter. One application where using a high resolution PWM has value vs. a traditional 8 Bit DAC is in driving the 3-wire voltage controlled fan in a PC.
MEC140x, MEC141x, MEC142x