About the shift in current in Id-Vg measurement

[sijie]

Hi Everyone,

 

When I was characterizing Id-Vg curve for my FET, I got something like this. I Used the topology like this.

Basically a common source configuration to measure the Id-Vg curves. I fixed the voltage output at wavegen1 and generate a triangular wave at wavegen2. However, I found that there's a displacement in current between the Vg going up and going down. Theoretically, there should not be any difference between the two, so I am pretty confused by this phenomena. Really appreciate if anyone could resolve my puzzle, thanks so much!

 

[attila]

Hi @sijie

Could it be caused by the different on/off resistance? Try a lower frequency.

[sijie]

Thanks! I tried 100Hz instead of 1k and it worked well!