Random PWM for SMPS? 5

[GonzaloEE]

Hi all,

I've read some papers on certain ramdom-PWM techniques for SMPS switching drivers (Google 'random PWM'). The authors claim reaching lower noise levels at the output, because - as they say, random switching spreads noise freq. components over a wider band than the standard clocked PWM.

I like the idea of having like 'white noise' at the output, easier to filter than those well-known voltage spikes of most SMPS.
Does anyone know where to get further info (or sample uC programs) on this subject?

Cheers,
Gonzalo

 

[Warpspeed]

Excellent advice Benta!

Those topologies offer some real advantages to reducing conducted noise at both the input and the output.

As I mentioned earlier, choosing an appropriate topology can put you way ahead in compliance. Switchers that normally produce violently pulsing currents, can be extremely difficult to filter.

Another technique is the appropriate use of electrostatic foil screens both within transformers, and sometimes between semiconductors and their respective heat sinks.

Avoiding what produces switching noise spikes in the first place will greatly reduce any filtering requirement.