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Topic: Frequency to voltage converter IC (Read 2379 times) previous topic - next topic

jmknapp

Very interesting, Mag--thanks for sharing what you've done.

BTW, for the anti-aliasing filter, I like the tools on this web site from Japan:

http://sim.okawa-denshi.jp/en/Fkeisan.htm

For example, the third-order Sallen-Key LPF which you can implement with 3 resistors, 3 caps and an op amp. Using the Chebyshev selection, looks like if you set the cutoff at 2KHz you could be almost 30dB down at 4KHz.

Joe


Magician

I'm afraid the filter that I need, isn't invented yet.   Roll off so sharp : 30 dB from 1976 to 2000 Hz........
(Nyquist with 4k sampling is 2kHz).  What it would be , 30-th order or something?
The other way, push sampling to higher rate, again , with more memory.

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