Stats

  • Locked Locked
  • Replies 5
  • Subscribers 126
  • Views 2083
  • 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

problems on a system's phase noise evaluation

reddevil011

Hello, I have a system shown as above, and aim to evaluate the phase noise of "OUT". But I am confusing about the simulation method.

A is an oscillator; B is a just a logic buffer with another power supply.

I think of some ways to evaluate the phase noise of "OUT", using spectreRF.

CaseA: run PNoise analysis with the whole system, including A and B, select noisetype=source. Use the simulation result "output noise"  to evaluate phase noise.

CaseB: evaluate phase noise separately. run PNoise analysis with A, select noisetype=source. Use the simulation result "output noise"  to evaluate oscillator's output. Then run PNoise analysis with B, select noisetype=timedomain. Translate the simulation result "Jee" to phase noise. The two items add to "OUT"'s phase noise.

I've tried the two ways to get output phase noise. But they get different results. I am wondering which is the exact way to evaluate this system's output phase noise.

Best Regards! 

Parents

  • Thanks for your reply, Frank.

    I've read the thread you offer, and still have some problems.

    The virtuoso version I am using can not get PM jitter for autonomous circuit yet. So, I should select Noise Type=timedomain in PNoise analysis, and use tdnoise to get jitter, by dividing the slope of output signal. 

    Is my understanding correct?  Thanks.

Reply

  • Thanks for your reply, Frank.

    I've read the thread you offer, and still have some problems.

    The virtuoso version I am using can not get PM jitter for autonomous circuit yet. So, I should select Noise Type=timedomain in PNoise analysis, and use tdnoise to get jitter, by dividing the slope of output signal. 

    Is my understanding correct?  Thanks.

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.