• Skip to main content
  • Skip to search
  • Skip to footer
Cadence Home
  • This search text may be transcribed, used, stored, or accessed by our third-party service providers per our Cookie Policy and Privacy Policy.

  1. Community Forums
  2. Custom IC Design
  3. Noise simulation in Cadence

Stats

  • Locked Locked
  • Replies 5
  • Subscribers 126
  • Views 22462
  • 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

Noise simulation in Cadence

EthanRFIC
EthanRFIC over 12 years ago

 Hi,

 I'm learning Noise Simulation in Cadence.  The circuit is just a simple common source amplifier with a noise-less resistor as the load. What I want to do is to observe the noise situation for the nmos transistor.

 

However, when I do the simulation, spectre is always terminated due to a fatal error showing: 

"ERROR(SFE-51): name conflict: value 'M0' of type 'scalar subcircuit instance' encountered. Expected value is of type 'scalar instance'.

 ---I've checked out the manual reference, but I still have no idea what the error is there.

 

So if anyone can help me out? Thank you so much!

 

The simulation setup is :

 Analysis: noise

Sweep Range: start=1, stop=100G.

Output noise: probe, output probe instance: /M0

Input Noise: None

 I'm using Cadence version of IC6.1.5-64bit

  • Cancel
Parents
  • EthanRFIC
    EthanRFIC over 12 years ago

     Thank you so much Andrew! It helps a lot! However, I'm still not very sure what to probe if I want to measure the output noise current. You mentioned "a voltage source/iprobe", then what is 'iprobe'?

    My test circuit is shown below. I want to test the thermal current noise "ID^2" of the NMOS transistor. Do you mean that I can just set up "probe the \VD" in the noise simulation setup (probe the voltage souece VD)? 

    I did probe the "VD" and it gave me a current plot, in the "result browser", there are some parameters which I want to confirm:

    fn: flicker current noise?

    id: thermal current noise?

    igb/igd/igs: current noise from gate to bulk/drain/souece?

    Am I right with those? Thank you very much! I'm very appreciate for your correcting.

    Best Regards,

    Ethan

    • 20130715164934.jpg
    • View
    • Hide
    • Cancel
    • Vote Up 0 Vote Down
    • Cancel
Reply
  • EthanRFIC
    EthanRFIC over 12 years ago

     Thank you so much Andrew! It helps a lot! However, I'm still not very sure what to probe if I want to measure the output noise current. You mentioned "a voltage source/iprobe", then what is 'iprobe'?

    My test circuit is shown below. I want to test the thermal current noise "ID^2" of the NMOS transistor. Do you mean that I can just set up "probe the \VD" in the noise simulation setup (probe the voltage souece VD)? 

    I did probe the "VD" and it gave me a current plot, in the "result browser", there are some parameters which I want to confirm:

    fn: flicker current noise?

    id: thermal current noise?

    igb/igd/igs: current noise from gate to bulk/drain/souece?

    Am I right with those? Thank you very much! I'm very appreciate for your correcting.

    Best Regards,

    Ethan

    • 20130715164934.jpg
    • View
    • Hide
    • Cancel
    • Vote Up 0 Vote Down
    • Cancel
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.

© 2025 Cadence Design Systems, Inc. All Rights Reserved.

  • Terms of Use
  • Privacy
  • Cookie Policy
  • US Trademarks
  • Do Not Sell or Share My Personal Information