There are two common methods to measure VT.
1:define Id=+-0.1uA
2:Vth Measure method:
> Step1:Vds=0.1 Vs=Vb=0 and sweep Vg
> Step2lot Ids µ Vgs and Gm µ Vgs curves Step3:find Gm(max),plot slop
> of this point on Ids Vgs From Linear function set Id=0 then
> Vth=Vgs-0.5Vds
the second method?
why GM first increases then decrease?
why we get VT at Max Gm point?
Is there any paper or patent to explain the theory?