Other Parts Discussed in Thread: OPA1656
I'm up to, to design a 3rd or 4th order 20 Hz high pass filter with ultra low distortion. Does anybody know design advantages of choosing a certain topology? Sallen-Key, variable state, etc? The grey book is a fine old book with thousands of variants of filter but nowhere does it say pros and cons of each type. If I google I don't get much useful info. Opamps in mind is OP1612 or OPA1656.
Grey book: Active and passive analog filter design - an introduction by Lawrence P. Huelsman (extremely theoretical)
Active-Filter Cook book by Don Lancaster (very practical book)