Stats

  • Locked Locked
  • Replies 5
  • Subscribers 130
  • Views 19089
  • Members are here 0
This discussion has been locked.
You can no longer post new replies to this discussion. If you have a question you can start a new discussion

Nyquist stability test using stb analysis

DCashen

I'd like to do a Nyquist test for stability. I can generate a Nyquist plot from the loop gain analysis. That'll give me the number of encirclements of -1. Now I need the poles of the loop gain. Is there a way to extract that from the stb results?

Thanks

Parents
  • Frank Wiedmann

    You can find the explanation for the multiplication with -1 at http://www.designers-guide.org/Forum/YaBB.pl?num=1124688329.

    By the way, what is shown in the video (http://support.cadence.com/wps/mypoc/cos?uri=deeplinkmin:VideoViewer;src=wp;q=Training/Custom_IC_Design/TrainingBytes/CreateNyquistPlots.html;DocumentType=trng,norcfeat,trngbyte,video) is really only half the Nyquist plot. In order to get the complete plot, you should plot the imaginary part of the loop gain (without multiplication by -1) as a third curve (before selecting "Y vs Y").

Reply
  • Frank Wiedmann

    You can find the explanation for the multiplication with -1 at http://www.designers-guide.org/Forum/YaBB.pl?num=1124688329.

    By the way, what is shown in the video (http://support.cadence.com/wps/mypoc/cos?uri=deeplinkmin:VideoViewer;src=wp;q=Training/Custom_IC_Design/TrainingBytes/CreateNyquistPlots.html;DocumentType=trng,norcfeat,trngbyte,video) is really only half the Nyquist plot. In order to get the complete plot, you should plot the imaginary part of the loop gain (without multiplication by -1) as a third curve (before selecting "Y vs Y").

Children
No Data

Community Guidelines

The Cadence Design Communities support Cadence users and technologists interacting to exchange ideas, news, technical information, and best practices to solve problems and get the most from Cadence technology. The community is open to everyone, and to provide the most value, we require participants to follow our Community Guidelines that facilitate a quality exchange of ideas and information. By accessing, contributing, using or downloading any materials from the site, you agree to be bound by the full Community Guidelines.