how to simulate cap value by PMOS?

[samuel]

can anyone tell me the details?

 

[Syukri]

what simulation tools do u use?

Simply used Hspice. when u write pMOS netlist is done before .end commad put .op command

it will give the operating point value....u can chechk all type of cap after simulation

 

[qslazio]

more accurate way is put a resistor (say 1K ohm large) series with a pmos cap. input is a AC signal and get the -3dB bandwidth.

Now you will find the Ceff=1/(2*pi*1K*F-3db)

 

[hr_rezaee]

see hspice user manual.

 

[MLR67]

Hum

remember what is the Laplace transforme of capacitor is something as 1/Cs with s=jw
Now if you use a logarithmique scale (as Bode plot) what do you get ?
-20 Log(w)-20Log(C) (So a draw in a X logarithmique scale).Nevertheless you need to polarize your PMOS Capacitor before to perform this AC simulation.
I hope it will help you on problem