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Design >> Analog Design >> Common-mode point for OPamp
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Message started by nxing on May 1^st, 2008, 12:07pm

Title: Common-mode point for OPamp
Post by nxing on May 1^st, 2008, 12:07pm

Hello everyone,

I have a question regarding how to setup the output common-mode voltage before connect the CMFB circuit. Should these points be close to what ever we want (for example, vdd/2) or it doesn't matter as long as the we can correct them with CMFB circuit?

Thanks!

Norman

Title: Re: Common-mode point for OPamp
Post by thechopper on May 1^st, 2008, 2:24pm

Hi Noman,

The CM voltage should be selected in order to guarantee the required differential signal excursion. Then the CMFB will be the one forcing such CM level and will obviously have to be designed for working at those levels.

Regards
Tosei