sjamil02
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I did simulation for a diode-connected NMOS to get the curve ft vs. gm/Id, Id/(W/L) vs. gm/Id and gm/Id vs. Vov. The results look ok.
However I get a strange curve when I did simulation for gmro vs. VDS curve.
Here's what I did:
I ran a simple NMOS dc simulation (fixed Vg=Vt+200mV and sweep VDS 0V-1.8V). Simulation was done in PSPICE.
To get gmro vs. VDS curve:
(1) Slope 1/ro is the derivative of Id vs. VDS curve.
(2) gm0=Id/(vgs-vt), in my simulation vgs-vt=200mV
gm=gmo*(1+lamda*VDS) where lamda=1/ro*Id
Please have a look at the graph and the data in the attachment. Anyone experienced can help me to shed some light?
cheers
sj
However I get a strange curve when I did simulation for gmro vs. VDS curve.
Here's what I did:
I ran a simple NMOS dc simulation (fixed Vg=Vt+200mV and sweep VDS 0V-1.8V). Simulation was done in PSPICE.
To get gmro vs. VDS curve:
(1) Slope 1/ro is the derivative of Id vs. VDS curve.
(2) gm0=Id/(vgs-vt), in my simulation vgs-vt=200mV
gm=gmo*(1+lamda*VDS) where lamda=1/ro*Id
Please have a look at the graph and the data in the attachment. Anyone experienced can help me to shed some light?
cheers
sj