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  1. #1
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    Stability of switch capacitor bandgap ?

    The bandgap in the attached photo has a feedback from the output. Obviously stability needs to be checked or it can show an output with oscillations.
    How do I determine the gain margin and phase margin of the system ?
    Can someone provide ideas for a test circuit to determine the stability parameters ?

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  2. #2
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    Re: Stability of switch capacitor bandgap ?

    Switched Capacitor (SC) circuit AC behaviour is usually simulated with 'storistor'. I cannot help more with that, try google, I remember P.E.Allen have some tutorials for it.
    Last edited by frankrose; 14th March 2019 at 14:06.
    "Try SCE to AUX." /John Aaron/



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  3. #3
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    Re: Stability of switch capacitor bandgap ?

    "State-space average models" are used on power conversion
    simulations, for speed (accuracy, in the details, is on you).

    I would be more inclined to a "stimulus-response" challenge
    in transient analysis, looking for supply, ground and load
    injection-points, perturbation and recovery from application-
    realistic "stimuli".

    Chopper mixing might produce some interesting frequency
    domain artifacts and what this does to stability analysis
    (especially "canned" stability analyses that just cough up
    an intercept-point, may be fooled by spurii) that probably
    wants inspection before belief.



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  4. #4
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    Dominik Przyborowski's Avatar
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    Re: Stability of switch capacitor bandgap ?

    Try ordinary pstb analysis



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