Mihir Mudholkar
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Hi,
I am using the Verilog-A version of the PSP 101.3 model to model one depletion and enhancement type device (all nmos). I have extracted the various DC parameters, and have reasonable fits for the model.
The problem is, when I simulate a simple inverter, with a depletion device on top, and a current source at the bottom, with the gate and source of the depletion device tied together, and a 16V rail DC supply to the depletion device + current source. When I sweep the current source from 0 to 20 fA (femto), I see that the output voltage (the source/gate terminal of the depletion device, which are tied) to start at 23V! constant for a few fA and then ramp down to below 16V. This is bizarre behavior, where the MOSFET has approximately -5V across its Drain-source, but a positive current flowing from the drain to the source.
Does anyone know what this problem might be?
Any information regarding this would be very helpful.
Thank you,
Mihir
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