Home > Community > Forums > RF Design > Finding DC operating points at certain timepoints during TRANSIENT analysis

Email

* Required Fields

Recipients email * (separate multiple addresses with commas)

Your name *

Your email *

Message *

Contact Us

* Required Fields
First Name *

Last Name *

Email *

Company / Institution *

Comments: *

 Finding DC operating points at certain timepoints during TRANSIENT analysis 

Last post Mon, Apr 1 2013 10:00 AM by Andrew Beckett. 3 replies.
Started by RFStuff 25 Mar 2013 05:42 AM. Topic has 3 replies and 1584 views
Page 1 of 1 (4 items)
Sort Posts:
  • Mon, Mar 25 2013 5:42 AM

    • RFStuff
    • Top 25 Contributor
    • Joined on Tue, Feb 5 2013
    • Posts 254
    • Points 4,505
    Finding DC operating points at certain timepoints during TRANSIENT analysis Reply

    Dear All,

    I need to run transient analysis of a circuit.

    However, I also want to find the dc operating points of some components at certain instants ( time points) during  the transient analysis on the FLY. The operating points may be logged to a file for analysing the data after the transient simulatuion is OVER.

    Could anybody please tell, is there any way of achieving this. I use IC5141 & MMSIM12

    Kind Regards,

    • Post Points: 20
  • Mon, Mar 25 2013 5:48 AM

    Re: Finding DC operating points at certain timepoints during TRANSIENT analysis Reply

    Two approaches:

    1. On the transient options form, there's a field called "infotimes" - specify the times at which you want it to output the dc operating point data. You can then annotate the "transient operating points" from any of these times after the simulation, or access them via the results browser.
    2. Or you could get the operating point data to be continuously saved during the transient for selected devices - if so, create a file called (say) "save.scs" (make sure it has a ".scs" suffix), and put:
        save M1:oppoint
      or
        save M*:oppoint sigtype=dev
      in this file, and then reference the file via Setup->Model Libraries or as a "definition file" on Setup->Simulation Files.
      With this approach you can then find the operating point data for the selected devices in the results browser and plot it versus time (be cautious of saving too much though because this can generate a lot of data if you're not careful)

    Regards,

    Andrew.

    • Post Points: 20
  • Mon, Mar 25 2013 6:05 AM

    • RFStuff
    • Top 25 Contributor
    • Joined on Tue, Feb 5 2013
    • Posts 254
    • Points 4,505
    Re: Finding DC operating points at certain timepoints during TRANSIENT analysis Reply

     Dear Andrew,

    Thanks a lot.

    The approach 1 looks suitable to me for large circuit blocks.

     Actually I want to write a ocean script, which intially calculate the desired timppoint and enter into the transient alnalysis before run. This can be doen.

    But, how the dc op points of certain components at the timepoints can be dumped into a log file. Basically how the OP( ) command can be used for giving DC operating point at multiple time points.Could you please throw some light into it.

    Kind Regards,

     

    • Post Points: 20
  • Mon, Apr 1 2013 10:00 AM

    Re: Finding DC operating points at certain timepoints during TRANSIENT analysis Reply

    For completeness, this question is dealt with in your other thread - http://www.cadence.com/Community/forums/p/25743/1322126.aspx#1322126

    • Post Points: 5
Page 1 of 1 (4 items)
Sort Posts:
Started by RFStuff at 25 Mar 2013 05:42 AM. Topic has 3 replies.