Hi,
By making simulations on a BSIM-IGFET nfet model the DC analysis gives logical results but the AC analysis don't ,it gives the following results:
anyone can give reason.
thanks in advance.
Hi,
By making simulations on a BSIM-IGFET nfet model the DC analysis gives logical results but the AC analysis don't ,it gives the following results:
anyone can give reason.
thanks in advance. View attachment 139353
There is something wrong with the variables or the model.
Your DC sweep indicates that /out increases with vin.
above threshold (#5 attachment). It should be inverse.
You show /out greater than /vdd.
Your AC sweep indicates voltage gain of 8.4mV/100mV.
That's a lousy gain. But similar to the DC transfer gain
of ~35mV/500mV.
Your "nfet" model is not acting at all like a NMOSFET
should. Maybe try substituting any of a zillion known
good NMOSFET models for the "guts" and see whether
the circuit responds as it ought to.