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Simulators >> Circuit Simulators >> how the cmdmprobe works?
https://designers-guide.org/forum/YaBB.pl?num=1330528335

Message started by NeilYu on Feb 29^th, 2012, 7:12am

Title: how the cmdmprobe works?
Post by NeilYu on Feb 29^th, 2012, 7:12am

hi all,
I try to understand the cmdmprobe in analogLib by raturn ratio method.
But I have a question why the pcccs source is added in it.

Thanks,
Neil

Title: Re: how the cmdmprobe works?
Post by sheldon on Feb 29^th, 2012, 5:02pm

Neil,

Which version of MMSIM are using? From MMSIM 10.1(?),
a new component has been released and it is the
recommended element for differential stability analysis,
the diffstbprobe. The cmdmprobe is still supported for
backwards compatibility.

Best Regards,

Sheldon

Title: Re: how the cmdmprobe works?
Post by NeilYu on Mar 1^st, 2012, 7:08am

Hi Sheldon,
Thank you very much for your comments.
I asked the question because I found that the DC loop phase is zero degree(180deg is reasonable). So I try to understand how the cmdmprobe works and I wonder why CADers add the pcccs. Due to the pcccs, the zero degree happens.
I just saw diffstbprobe in my version. But the details about diffstbprobe are not available. What's the difference between diffstbprobe and cmdmprobe?

Thank you very much & Best Regards
Neil

Title: Re: how the cmdmprobe works?
Post by Frank Wiedmann on Mar 1^st, 2012, 7:40am

The diffstbprobe has the advantage that it also works correctly for non-symmetrical circuits. See http://sites.google.com/site/frankwiedmann/loopgain#TOC-Loop-Gain-of-Differential-Circuits for some details.