Stats

  • Locked Locked
  • Replies 9
  • Subscribers 63
  • Views 5970
  • 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

Problem when using RFDE momentum blocks in Cadence (Drop across Resistance w/o any current)

dipal261

Hi,

I have a problem with the use of RFDE mom symbol view in Cadence schematic. The image is attached below for reference. The momentum block is basically a MOM capacitor for coupling ac input . In theory, there should not be any drop in the 3KOhms resistance connected to the gate of the transistor in one end and the capacitor on the other end. This entire block works fine if I simply remove the MOM model with an ideal capacitor from analoglib. In that case, I see no drop across the 3K Ohms resistance. But when using the MOM model, it simply destroys any gate biasing that I try to put. What is the problem here? and how can I get a work around it?

This is a dc analysis and shows the current and voltage at each node.

Thank you.

 

Regards

Dipal

Parents

  • Dipal,

    Given that Momentum is a tool from Keysight (not Cadence) and I don't know which version of Virtuoso, Momentum, or Spectre (assuming that it's spectre you're using as the simulator - you didn't say that either), it's quite hard to give a definitive answer.

    So, assuming that the simulator is spectre, can you post what the lines in the input.scs look like for I741 (the highlighted component above)? Also can you mention the versions of the tools you're using?

    Thanks,

    Andrew.

Reply

  • Dipal,

    Given that Momentum is a tool from Keysight (not Cadence) and I don't know which version of Virtuoso, Momentum, or Spectre (assuming that it's spectre you're using as the simulator - you didn't say that either), it's quite hard to give a definitive answer.

    So, assuming that the simulator is spectre, can you post what the lines in the input.scs look like for I741 (the highlighted component above)? Also can you mention the versions of the tools you're using?

    Thanks,

    Andrew.

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.