90nm transconductance value. how to predict?

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evilguy

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As we know the square law equation:

Id = k'/2×W/L(Vgs - Vt)²

k' = µoCox

in 90nm, how we can predict the value in order to do hand calculation? can someone tell me the approch on how to design in 90nm process. thanks
 

if you have the spice model, that is easy... (BSIM4 models are good)

if you do not, the hand calculation can be far away
 

yes i have BSIM4 model. from BSIM4 model, how can i extract the transconductance value? how to design circuit let say current mirror straight away without doing hand calculation 1st? of course hand calculation is just for guide only. the simulation result and hand calculation will be totally not similar.
 

well, there are many ways ...

The simple way is just do an I-V curve simulation and use calculator to get the gm and other key parameters
 

from I-V curve, how to get gm? can somebody instruct me? if we do dc point analysis in spice, the gm parameter is extracted in the output file. then using what equation can we get k'? can we just use the level 1 MOS model to find k' in 90nm process?
 

The drain current doesn't follow the square law equationin short channel like 90 n technology so it does not make sense if u are looking for K,
ID= w*vsat*C'ox(VGS-VTHN-VDS,sat)
for more informatiopn about short channel design refere to : Jacob Baker 's "CMOS" book.page 153
 

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