how to hand calculate them?

[amriths04]

how to calculate lambda by hand

for a tanner simulation of cmos opamp how do i calculate the values for kp,kn and lambda? as they are not given directly in the model file..

as only if i know kp pr kn i can find the correct transistor sizing, pre hand. please help.

 

[rush3k]

the model files from mosis will usually have the kp and kn values. if you dont have this information, then kn=Un*Cox ... Un is mobility of NMOS, Cox (Eo*Kox/Tox) is oxide capacitance, Eo is permitivitty of space, Kox is the dielectric constant, Tox is the oxide thickess. Be careful what units you use when you do the calculations. do same for kp.

lambda will have to be characterized. do an id-vd characterization and use the slope information for the device in the saturated region to estimate the lambda. the inverse of the intercept on the x-axis (vd axis) gives you lambda.

 

[amriths04]

lambda will have to be characterized. do an id-vd characterization and use the slope information for the device in the saturated region to estimate the lambda. the inverse of the intercept on the x-axis (vd axis) gives you lambda.

rush3k, i am not able to understand the above idea. could you please elaborate.

like at what point need i calculate the slope and and why that intercept on x axis?

 

[rush3k]

This is the BJT equivalent ... I hope this helps you get the idea. In the case of MOS, the inverse of the the early voltage is the lambda value.