> Sounds like any chip with more than 8 I/O pins could do it in
> some form or
> fashion.  200khz of bandwidth (4x50khz) takes up only 4% of
> the available
> instruction cycles on a pic running at 20mhz, leaving quite a
> few cycles to
> sample your input, do some math, then generate PWM on the output.

I think there is an error in this calculation. A PWM channel at 50 kHz
with 8 bit resolution requires a 'time-wise resolution' of 50 MHz x 256
= 12.8 MHz. That might barely be possible with an SX, or and 18F, and
maybe one channel could be done on a PIC, but I would like to see the
code to run four such independent PWMs.

Wouter van Ooijen

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