bandpass active filter Current feedback

dragon_03 said:

i want to design bandpass active filter Current feedback (CFA) with the center frequency 50MHZ by using sallen-key topology.
i would like to know which OP amp i have to use and its possible to increase the center frequency to 100MHZ

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dragon_03 said:

i want to design bandpass active filter Current feedback (CFA) with the center frequency 50MHZ by using sallen-key topology.

i would like to know which OP amp i have to use and its possible to increase the center frequency to 100MHZ

Click to expand...

keith1200rs said:

You cannot put reactive components (capacitors or inductors) in the feedback of current feedback amps.
Keith.

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LvW said:

keith1200rs said:

You cannot put reactive components (capacitors or inductors) in the feedback of current feedback amps.
Keith.

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Hi keith,

I am afraid you have overlooked the fact that in Sallen-Key (S+K) structures the CFA is used as a noninverting amplifier without any capacitive feedback. The S+K topology is the only one which allows CFA`s .

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keith1200rs said:

................
My mistake. Thanks. Sorry if I caused any confusion to anyone.

Keith.

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LvW said:

keith1200rs said:

................
My mistake. Thanks. Sorry if I caused any confusion to anyone.

Keith.

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Don't mention it.
Regards

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keith1200rs said:

...........

I must admit, when I get to 50MHz or above I would probably be looking at passive LC filters, but it depends on the applications.

Keith.

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