How to select pi-filter cut-off frequency w.r.t power converter cross-over frequency

Thread Starter


Joined May 22, 2019
What is the process for calculating the pi-filter second stage cut off frequency? I know it needs to be sufficiently below the switching frequency to ensure that high frequency filtering is provided and noise-attentuation also - but what I am curious about is whether there is any interaction between the output filter cut-off frequency and the converter cross-over frequency. For example. cross-over frequency can be selected as FSW/10, say 25kHz. What would happen if the filter cut-off frequency was placed here? What would happen is the frequency was 5kHz higher or lower than this?

Might be a stupid question but I am curious and have not really read anything about this interaction - which might be nothing. :)