[moved] unable to plot in cadence

[preethi19]

Hi i designed a simple circuit and i saved the output current and i am able to see the current value and the region of the transistors in print annotate. so the circuit has no problem in functioningcorrectly. But the output waveform window is blank. I chose the transistor drain as the output to be plotted and i am getting error "Trying to plot expression .... which does not evaluate to an object that can be plotted". Can anyone pls help me!!!

 

[Debdut]

Have you used the calculator to form the expression?
If you have, then plot the signals (V or I), which you are using to create the expression, separately and see if all of them plots.

 

[dick_freebird]

Just because you see the .OP backannotated does
not mean the simulation ran; they could be residual
from the last time and simply "turned on" for display.

If you did get an OP result, that does not mean you
got a successful tran or ac (or whatever it is you
want to plot) - you do not mention running a tran
analysis.

If you did run an analysis successfully, the Calculator
is very fussy about syntax and data sources. Pick
the right v() and the wrong analysis type, you'll get
nothing.

Debug your calculator expressions by trying to
print the value of the expression and preferably
any of the elements of it that are at all questionable.

 

[preethi19]

Yes i have tried the calculator for a DC analysis. I am just trying to do a DC run for a simple nmos transistor to plot ID vs VDS..