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Sep 19th, 2020, 11:33am
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stability for ckts having one feedback and one forward loop (Read 58 times)
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stability for ckts having one feedback and one forward loop
Sep 4th, 2020, 8:05am
I designed a circuit having one feedback and one feed forward loop, the feed forward loop is used to provide a zero to improve the phase margin of the feedback loop.
When I break the feedback loop, the stb analysis shows the loop is stable, but when I break the the feedforward loop, the stb analyais shows the loop is unstable.
The transient reponse of the circuit is stable.

In cadence help file "spectreref.pdf", it says: The  loop-based algorithm can only be performed on individual feedback loops to ensure that they are stable. Although the stability of all feedback loops is only a necessary condition for the whole circuit to be stable, the multi-loop circuit tends to be stable if all individual loops are associated with reasonable stability margins.

Does cadence mean that if one of the loop of a multi-loop circuit is unstable, the whole circuit is unstable?
How can I check the stability of the circuit I designed?

Thank you very much.
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« Last Edit: Sep 05th, 2020, 5:11am by tulip »  

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