Hi Cristian,

Thanks for the info, but I don't think it quite answers what I was after:

A "conventional" parallel-output ADC gives you instantaneous samples of the analogue input waveform's amplitude, but for PWM you need to know what pulse width will give the required analogue amplitude at the filter output.

So, what I was wondering is how do you convert the analogue amplitude samples to pulse widths for the PWM output?

I presume there must be a technique to do this directly? (ie, straight to pulse widths, rather than via amplitude samples)

For the kind of thing I was thinking of - and, I think, for Waqar's Big Ben project - the generation of the PWM data could be done "off-line" (eg, on a PC); it wouldn't need to be done by an 8501.