Multisim and Ultiboard

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Diode reverse voltage problem


Hi Folks,


I havea simple circuit consisting of a 12V AC source, a diode and a series resistor that are instrumented up to show the voltage and current at various points.I would expect to see current flowing through the diode and resistor only when the diode is forward biased but there is something going on with the simulatiuon that doesn't make sense to me.


The schemaic is shown first below followed by a DC Sweep test, which looks good. The third image is the simulation and as you can see there is a rather significant current flowing hrough the resistor when the diode should be off. Reverse leakage current should be perhaps 0.3 mA based on the MBRS540T3 data sheet..


Any help would be appreciated.




Single Diode Test Schematic.jpg

Single Diode Test DC Sweep.jpg

Single Diode Test Simulation.jpg



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Message 1 of 3

Hi MyamigoSH


I tried to simulte the same circuit and this are my results.



But Also I was wondering which values are you using for the Start value and the stop value of the DC Sweep analyses  




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Message 2 of 3

Thank you for the response. I figured out that the problem is with the 4-channel oscilloscope. The 2-channel version works fine.



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Message 3 of 3