I need one with 4 or 6 pwm controls and if it could be controlled with a com mprt, it would be great!
Dozens, but the MIC502 and a few others (eg TC646) have been purpose-designed to run brushless fans so have a few specialised features and need fewer other components. All you need is an oscillator giving a saw-tooth or triangle waveform, an adjustable reference voltage (pot or thermistor), a comparator and a modest power transistor. Quite a few circuits use 555 or 556 timers to produce a square-wave with variable mark/space ratio.
ok I want to build a PWM fan controller, but controlled with a computer com port how could I build it?
