Yes, output voltage can be specified by gm*(Rout) of the circuit, but could you post a schematic of the circuit if you have it? It would be easier to explain.
we can not clearfy these things without seeing the circuit.... but i think th Rd in "Av=gm Rd" must be the load input impedance that when we use pmos as a load in teriod region, it came to bo 1/gm(Rd=Rds,teriod=1/gm); (gm=Kt(Vgs-Vt)^2)
these are some formulas that we can easily calculate them with ac models of transistors....
i said it is true in DEEEP triod region, where the Rds of MOS trinsistor is approximated by 1/gm....
deep teriod means that Vgs<<<Vt.
otherwise the real Rds value is calculated by absouloute bias values of Id and Vgs in folowing equ.:
Id=k((Vgs-Vt)Vt+....) i dont remember it completely....i do not think it is important for you....
gain = gm*Ro.
gm -> input transistor transcoductance (of the diff opamp).
Ro depends on how u have implemented the load,it can be either nmos or pmos.,
if its a pmos load,in triode region.
if u wnated to increase the gain,either the gm can be increase,or either the Ro value.
hi
I got that , but when they say in some ckt (Common source) with PMOS as load and NMOS current source connected to the S of CS amp. , that the set the Av=6 .
I did not get the meaning of that , and how we set it .
thankz - attached the ckt , the output taken from drain of 1st NMOS