• 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. Finding Large signal Drain-Source resistance (Rds) for BSIM...

Stats

  • Locked Locked
  • Replies 3
  • Subscribers 125
  • Views 14251
  • 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

Finding Large signal Drain-Source resistance (Rds) for BSIM-CMG (106.1) model in SPECTRE by DC analysis

RFStuff
RFStuff over 5 years ago

Dear All,

I am simulating a Fin-FET device with BSIM-CMG (106.1) model in SPECTRE by DC analysis.

I see only gds and rout operating parameters in DC Operating point list. 

rout is found to be 1/gds. 

I am trying to find the Large signal Drain-Source resistance (Rds)  (VDS/IDS).  rout is NOT same as Rds. Also, I don't see "ron" parameter here.

Is there any other way to get this parameter in Spectre DC analysis ?

Kind Regards,

  • Cancel
Parents
  • ShawnLogan
    ShawnLogan over 5 years ago

    Dear RFStuff,

    RFStuff said:
    Is there any other way to get this parameter in Spectre DC analysis ?

    Is there a reason you don't want to use a DC analysis with the device configured in a common source configuration where the drain-source voltage is increased with constant VGS and measure the DC current. for low values of RDS, the impact of RD will be negligible, but it will dominate the current for large values of VDS. Hence, the slope of the VDS/IDS measurement should provide a good estimate of RDS. This is how the parameter is measured in the lab (except it is often a pulsed measurement to allow the value to be measured at a given ambient temperature accurately).

    If I am overlooking something in your question, I apologize, but tis is how I would approach it.

    Shawn

    • Cancel
    • Vote Up 0 Vote Down
    • Cancel
  • Andrew Beckett
    Andrew Beckett over 5 years ago in reply to ShawnLogan

    RFStuff,

    You could also use VIew->Annotations->Setup and change one of the outputs (or add a new output) to annotate vds/ids (you can output a calculation based on existing operating point parameters)..

    Andrew.

    • Cancel
    • Vote Up 0 Vote Down
    • Cancel
Reply
  • Andrew Beckett
    Andrew Beckett over 5 years ago in reply to ShawnLogan

    RFStuff,

    You could also use VIew->Annotations->Setup and change one of the outputs (or add a new output) to annotate vds/ids (you can output a calculation based on existing operating point parameters)..

    Andrew.

    • 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