[SOLVED] Measuring the on-resistance of a pmos in triode region

[milvapp]

Hi all ,

i want to measure the resistance of a pmos (operating in triode region)
in Cadence and i want you to suggest me a practical way to do that.I am quite amateur to
this,although i used s parameter simulation i didnt have any results.

Thank you in advance

 

[pavel_adameyko]

Hi, milvapp.
Resistance of pmos you can measure in circuit like this

Just do ac analysis in frequency range of interest. For example, for the circuit above ac gives the following results for real and imaginary part of resistance from drain (source V0):

You can vary dc voltages of sources V0,V1,V3 to change bias point of transistor.
Regards, pavel.

 

[milvapp]

First of all thnx for the help Pavel

However, i dont know how to plot the real part of the resistance.
Should i do something with the cadence calculator?

 

[pavel_adameyko]

Before performing ac analysis do
Outputs->To be saved->Select on schematic
and select current from PLUS terminal of V0 source.
After ac analysis press button if in calculator, select PLUS terminal of V0 source - expression IF("/V0/PLUS") would appear. Then modify it to get -1/IF("/V0/PLUS"), then press button real or imag to obtain real or imaginary part of resistance.
Regards, pavel.

 

[milvapp]

Before performing ac analysis do
Outputs->To be saved->Select on schematic
and select current from PLUS terminal of V0 source.
After ac analysis press button if in calculator, select PLUS terminal of V0 source - expression IF("/V0/PLUS") would appear. Then modify it to get -1/IF("/V0/PLUS"), then press button real or imag to obtain real or imaginary part of resistance.
Regards, pavel.

Thank you again.