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Cadence Calculator Expression

JustinTaylor86

Hi

I am trying to plot a histogram of Input Impedance (mu and sd) of an amplifier over 200 MC runs at 100KHz.

Expression 1 :  (VF("/vin")/IF("/V4/PLUS")) provides me with a wave plot of input impedance v freq which is fine but for quick verification the histogram is more useful for me.

Expression 2:  value(VF("/vin")/IF("/V4/PLUS"),100000,?histoDisplay nil ,?noOfHistoBins 1 ) produces an empty plot and the ICFB window says"Valid data not found....check expression/filter settings"

 

What is the problem with Expression 2?

 

Thanks

 

  • Andrew Beckett

    I've not tested this, but my guess is that it's to do with the fact that the expression is complex. For expression 1, it will end up with a complex impedance versus frequency, and when you plot it, it will automatically plot the magnitude.

    For the second expression, it's trying to take a histogram of a complex number which is probably not allowed (I can imagine it would be a challenge). So try:

    value(mag(VF("/vin")/IF("/V4/PLUS")),100000,?histoDisplay nil ,?noOfHistoBins 1 )

    That said, I'm not sure the ?histoDisplay being nil makes sense, and I think you'll need more bins. Otherwise I think you're just plotting the value versus the iteration...

    Andrew.

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