How can i plot vth vs L in cadence? (NOT vtho)

[currentmirror2000]

hi all,

i'm trying to plot vth vs L in candence, but what i can select is only vtho, i.e. MP("NM0" "vtho"); the vtho is independent of biasing.

what i did is to sweep L in parametric simulation and plot MP("NM0" "vtho") as the output.

can cadence output vth instead of vtho by sweeping L? is there anything wrong in my simulation, because even the vtho output curve looks very weired.

thanks in advance!

c.m.

 

[Fom]

You can plot Vgs at max gm using calculator special functions.
Use DC analysis with Vgs sweep and parametric analysis sweeping L as parameter.
Then plot xmax(deriv(Id)). It will plot Vgs at gm max vs. L.