parra
Newbie level 6
Years ago I learned that passive CL filters have less losses than passive RC filters, as, if they are in resonance, have almost no resistance. Also, to get a 2nd order filter, you need just two elements (1 x C, 1 x L) compared to four elements you'd need for a 2nd order RC filter (2 x R, 2 x C).
Though, if you look at real world circuits, RC filters seem to be prefered as long as your corner frequencies are not in some MHz. What's the reason why LC filters aren't used instead?
Of course low frequencies mean big L's, but even for some µH the ohmic part of a inductor usually doesn't get bigger then 1Ω, so the losses must still be well below an RC filter.
Though, if you look at real world circuits, RC filters seem to be prefered as long as your corner frequencies are not in some MHz. What's the reason why LC filters aren't used instead?
Of course low frequencies mean big L's, but even for some µH the ohmic part of a inductor usually doesn't get bigger then 1Ω, so the losses must still be well below an RC filter.