Spice parameters from mosis and Ro of MOSFET

[jn_mohit]

mosfet ro

Please help me with the following questions, they have confused me a lot

1) In the spice parameters file provided by mosis (for example **broken link removed** ), What does K' refers to, it says here that K' is (uo*Cox/2) but when i use this value for my simulations I dont get a correct result, rather this K' value is closer to uo*cox.

2) If I have to find Ro for a MOS transistor, i use formula 1/(lambda*Id), where lambda is channel length modulation factor, how can I find lambda using this spice file.
I dont want to find exact Ro for each transistor, but would like to know the approximate value which I should use for hand calculations and basic analysis.

Thankyou

 

[jyq_analog]

ro mosfet

The Lambda is provided.
The ro will chang with the different Vds .When the Vds is low, the change is very large. Hopeless to model ro with this simple equation.

 

[jn_mohit]

mosfet spice parameters

Hi thanks for your reply, but probably you didnt get my question, Ro ofcourse changes, but when you do the basic design of an op-amp lets say, you cant take that in to account, so I wanted to know what lambda to take in order to begin the designing.

 

[v_naren]

how to find spice parameters