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Design >> Analog Design >> CMFB for pseudo differential amplifier
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Message started by yixiusky on Dec 2^nd, 2008, 9:17pm

Title: CMFB for pseudo differential amplifier
Post by yixiusky on Dec 2^nd, 2008, 9:17pm

I would like to ask one question:
when we design pseudo differential amplifier, the common mode feedback circuit also should pseudo differential (without tail current source) or not ?

thank you very much

Title: Re: CMFB for pseudo differential amplifier
Post by loose-electron on Dec 5^th, 2008, 1:13pm

Could you please better define the question? Differential architectures I think we all understand, Complimentary architectures most of us understand. but what is "pseudo differential?"

thanks - Jerry

Title: Re: CMFB for pseudo differential amplifier
Post by rf-design on Dec 15^th, 2008, 1:59pm

Pseudo-differential means two single-ended stages used with complementary signals. Typical no common-mode rejection but if the signals are used as differential cancelation of some negative effects could occur.

No commom mode control needed. If the single-ended stages make a level shift between in and out and you can control that this will be a common mode control.