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 Using ADE calculator on x-axis with DC sims 

Last post Sun, Feb 22 2009 7:11 PM by sporre. 2 replies.
Started by sporre 08 Feb 2009 07:56 AM. Topic has 2 replies and 2765 views
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  • Sun, Feb 8 2009 7:56 AM

    • sporre
    • Not Ranked
    • Joined on Sun, Feb 8 2009
    • Posts 5
    • Points 70
    Using ADE calculator on x-axis with DC sims Reply

    When I run a DC sim with a swept DC voltage, such as a gate voltage, and then I plot a current, the plot puts the current on the y-axis and the swept DC voltage on the x-axis.  Is there any way to apply calculations to the x-axis (swept DC parameter) the way that you can with the y-axis data?  For example, when I sweep the gate voltage on a PMOS device, I would rather plot Ids versus Vg-VDD instead of Vg with respect to ground. 

     Does anyone know if this is possible?

    • Post Points: 20
  • Fri, Feb 20 2009 10:20 AM

    • Jim McMahon
    • Top 500 Contributor
    • Joined on Fri, Feb 20 2009
    • San Jose, CT
    • Posts 21
    • Points 355
    Re: Using ADE calculator on x-axis with DC sims Reply

    Yes.

    After the simulation completes and the DC results are plotted, do the following:

    1. Open the Calculator and create an expression for the x-axis quantity. E.g. VS("/gate") - VS("/vdd").

    2. Make sure the plot mode is set to "append" and plot the expression. The expression should now visible in the graph window.

    3. Double-click on the x-axis to access the axis attributes. Change the "Plot vs." field to above expression and "OK" the form.

     Jim

    • Post Points: 20
  • Sun, Feb 22 2009 7:11 PM

    • sporre
    • Not Ranked
    • Joined on Sun, Feb 8 2009
    • Posts 5
    • Points 70
    Re: Using ADE calculator on x-axis with DC sims Reply

    Jim, thanks for replying.  I tried it and it worked.  The timing of your answer was perfect, because I had another school assignment tonight that I needed this answer for.  Tonight I actually needed to do the same thing for a transient simulation, and that worked also.  For example, I needed to plot Vout vs. Vin for a digital gate using a transient sim.  The same method works. 

    • Post Points: 5
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Started by sporre at 08 Feb 2009 07:56 AM. Topic has 2 replies.