Capacitance Multiplier on SMPS

[jkeny]

Has anybody tried this to reduce HF noise on SMPS. AFAIK cap mult acts as an inductor & so HF is attenuated more. Would this be a good way of removing the HF spikes on these PS?

The idea is here: http://www.acoustica.org.uk/t/3pin_reg_notes2.html

 

[Eva]

Use an inductor...

 

[jkeny]

But I also need a good bit of capacitance on the power amp PS to aid peak current delivery!

Eva, I take it from your answer that there are no down-sides to its use - just that you think it overkill when an inductor would do? Does the above requirement change this?

 

[Eva]

An inductor for filtering stuff above 20Khz is not that big, particularly if it is followed by a large capacitance value. The only thing to worry about is the Q of the resulting RLC system, it should be damped. A common-mode filter is even better.

Any good SMPS won't require additional filtering anyway.