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Zapitgood
Mar23-09, 07:43 PM
Trying to simulate leakage current, say from a reverse bias diode or even a dirty PCB. Getting funny results using the current source across the load. Anyone have any ideas.


Basic voltage divider fed by CV source and a 1uA forward biased CC source across the VD tap.

By the way, I'm fairly new to SPICE and using 5Spice Analysis

berkeman
Mar23-09, 10:47 PM
Trying to simulate leakage current, say from a reverse bias diode or even a dirty PCB. Getting funny results using the current source across the load. Anyone have any ideas.


Basic voltage divider fed by CV source and a 1uA forward biased CC source across the VD tap.

By the way, I'm fairly new to SPICE and using 5Spice Analysis

The diode model has the reverse saturation/leakage current built-in, "Is". That isn't working for you?

Could you post your SPICE schematic screenshot, and explain a little more about what you are trying to model?

BTW, you do know that if you "Zapitgood", that the leakage current will likely change, right? LOL.

Zapitgood
Mar24-09, 11:30 AM
I think I figured it out, forgot that SPICE inserts a resistor in parallel with current source and in series with voltage source to prevent simulation problems. Of course I was working with "ideal" components as that's all I stock in my lab... I pay extra for those you know.

Thanks for the response berkman, I hope to be called Zapitbest some day... BTW, was trying to estimate what kind of errors I might get with various protection diodes across a decade divider feeding a DPM. This is the current return of a 40KVDC insulation tester.