harpoon wrote on Aug 22nd, 2013, 5:45am:Hi buddypoor,
I was just looking at these numbers you posted ... 3.5uF and 10kOhm to generate a 0.2Hz corner looks too good to be true, can you check if this is correct ? thanks ...
It is a bandpass with a mid frequency of app. 4.5 Hz.
Corner frequencies (3 dB) at 0.2 Hz and 100 Hz.
Topology: Tow-Thomas (2 integrators) - that means: 2 capacitors.
The given values (10k, 3.5µF) are correct.
Please note that sometimes there is a confusion regarding the order of a bandpass.
Lowest possible order is n=2 (Denominator polynominal of 2nd order).
Some authors/programs claim that this would be first order (n=1).
However, this is not correct: The order is determined by the denominator.
For a higher order (n=4 with 4 capacitors) I get: Rmax=10k and Cmax=79 µF