Hi,
Before looking at an MFB filter I simulated a cascaded low pass and high pass Butterworth and found the transition from pass to stop was too slow
active filters. Chose specs of high Q...
For flat passband and sharp stopband transition and minimum parts count, which is the most appropriate topology?
You can get sharper rolloff with multiple LC networks. Similarly you can do it with multiple active filters. I used a biquad filter (3 op amps & 3 RC networks), to extract a particular morse code broadcast, when one or two others were audible a few tone-steps away. Another type I considered was a state variable filter. They were one of many I saw in the Active filter cookbook.
May we finally hear a quantitative filter specification?
You are describing an ideal filter. A real filter has limited flat pass band, finite steep transitions and still passes some signal residuals in the stop band.So, to define specifications: if for example, the passband were 9.5kHz to 10.5kHz and the required transition were intended to not pass anything outside this range at the output, which topology would give suitable results using few(-est) parts? Would Sallen-Key be more appropriate for what is intended?
sharp stopband transition
I'm sorry, what do you mean? I think I stated where I am with filters from the word go. Presumably I'm not up to answering your question or you haven't understood my posts, just as my original questions in post #1 haven't been answered so by now I consider this thread a waste of time and generally unhelpful. I asked the questions to learn about this subject, not to be patronised,I'm afraid. If with two schematics and response graphs and a beginners description of what they are attempting to achieve or interested in discussing it's not yet clear, I guess it will never be.
I'm closing this thread as it really does seem pointless to go round in circles.
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?