Hi,

I am simulating rfnmos1v in TSMC 0.13 with the set up as follows:

Generally, I swept Io and plot ig, id, Vg, Io accodring to Io.
Could anyone help me explain the theory behind the curves of Vg and id.
I can't explain why they have the shape like that.
As in the picture,ig = 0 all the time. In the initial stage, id = Io. However, after Io > 0.3A, id almost saturated and not increase much.I am wondering why id isn't equal to Io after that time.
BTW, I drew the small signal model but that doesn't make sense at all as the circuit has no independent source, the only dependent current source here is gm*Vgs, and I can't calculate anything.

Here is the circuit for simulation:

Here is the result:

Thank you.
You are right. I am using 1V transistor.
In that case, the transistor is breakdown?