Hi
I am not good at drawing small signal circuits from the given MOSFET circuits. But I tried for one circuit here, I need someone to verify it and correct me if I am wrong?
2 attachments below has my answer in one and my unsure areas mentioned along with the question in the other.
Thank you.

 

Can someone please help me understand this...
Can we always replace the diode connected MOSFET with a resistor (1/gm) or in small signal model?
Also, Do we take gate voltage of the FET connected to the DIODE connected transistor as 0 if (1. same current flows through it(as it is in saturation), i.e constant voltage at that point= DC voltage= AC ground? 2. if that point is also connected to a DC source?)
I have a MOSFET problem to solve and then do spice simulation of the same....to compare the results.(image attached)
thank you in advance for any help or suggestions.

 

Please compress the file size to as 800x600 or 1024x768(if needed) before you attach them, the above files I already compressed to 800x600.