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  1. #1
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    Interpretiing data from Cadence stability analysis

    Hi.

    For the following inverting amplifier config using fully diff folded cascode opamp:

    Click image for larger version. 

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    should the loop gain found using STB analysis (CMDM = -1) equal to [ (open-loop gain of opamp) * (beta) ] ?
    - or is the loop gain not so easy to be calculated? - because, my simulation result is not matching with such calculation!

    (here, I used beta = feedback factor = 1/11, and the open loop gain was found from open loop simulation)

    A reply in this regard will be very helpful

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  2. #2
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    Re: Interpretiing data from Cadence stability analysis

    I had enough trouble from the stb analysis (coming up
    with absurd operating points and giving way-bogus loop
    gain) that I gave up on it and went back to old school
    methods. You just can't trust it to work each and every
    time, like you need to ever get through your Monte Carlo
    compliance analysis.


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