I have a hard time analyzing small signal for PMOS. I have seen that you reverse the voltages and saturation equation but that is just with biasing it. I am still confused on how to deal with small signal. I am using the Razavi Fundamentals of Microelectronics and it uses the NMOS small signal for the PMOS small signal. How can this make any sense.

How do I draw out the small signal for PMOS for pi model and t-model. I am trying to analyze the attached circuit to get the gain. I think using t-model would be easier but I also want to know how to use pi-model.

 

Small-signal ignores the DC bias conditions so it makes no difference if it's a PMOS transistor or an NMOS transistor for small signal calculations. Both NMOS and PMOS transistors amplify the same for small AC signals.

 

Small-signal ignores the DC bias conditions so it makes no difference if it's a PMOS transistor or an NMOS transistor for small signal calculations. Both NMOS and PMOS transistors amplify the same for small AC signals.

Yes but how do I treat their small signal. I haven't done enough of these to where I can just solve it by inspection so I have to draw out their small signal by hand. I know Vgs become Vsg but in my books, the treat the small signals as if they are the same