Stats

  • Locked Locked
  • Replies 0
  • Subscribers 63
  • Views 3867
  • 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

Crystal Oscillators

Youssef khaled

Hello, Currently i am designing a 96MHZ crystal oscillator using pierce topology and also I use for amplitude gain control circuit for regulation. The problem is when i run a PSS + Pnoise i get these warnings :

WARNING (CMI-2375): M2: Vgs has exceeded the oxide breakdown voltage of `vbox' = 6 V.
WARNING (CMI-2375): M4: Vgs has exceeded the oxide breakdown voltage of `vbox' = 6 V.
WARNING (CMI-2377): M4: Vgd has exceeded the oxide breakdown voltage of `vbox' = 6 V.
WARNING (CMI-2377): M3: Vgd has exceeded the oxide breakdown voltage of `vbox' = 6.6 V.

and also WARNING (CMI-2682): M5: The bulk-drain junction forward bias voltage (1.38154 V) exceeds VjdmFwd'=851.514mV ,The results are now incorrect because the junction current model has been linearized

Note : i am using Supply 1.2 V hence it is not possible to exceed the oxide breakdown. 

So i am asking why i am getting these warnings , it could be a convergence problem and the Results computed are not corrected.

Also when running DC and transient , i don't get these warnings.

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.