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Cadence Calculator Expression

JustinTaylor86
JustinTaylor86 over 13 years ago

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

 

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  • Andrew Beckett
    Andrew Beckett over 13 years ago

    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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