Triode region of NMOS transistor

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sungyueh

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deep triode subthreshold

Hi,

Is it true that a NMOS is easier kept in the triode region if its W/L ratio it larger?

Thanks.
 

easier kept on subthreshold region......current density will be very low...

Amit
 

To keep any trnaistor in triode region, Vds must be smaller than the saturation voltage defined as Vdssat=2/(n*gm/Id), where n is the inverse of the subthreshold slope.

For a given Id, as W/L increrases, gm/Id does it too and then Vdssat decreases. In the limit (very deep) of subthreshold conduction, Vdssat saturates to about 3-4Vt, where Vt is kT/q.
 

you can use the triode region of the MOS as controllable conductance. Works great for transconductance stages with ground refered input voltage. If L get longer the linearity improves. For most techs 4*Lmin works.
 

rfsystem said:
you can use the triode region of the MOS as controllable conductance. Works great for transconductance stages with ground refered input voltage. If L get longer the linearity improves. For most techs 4*Lmin works.
why L get large, the linearity improves? Thank you!
 


channel length modulation has less impact?
 

HI
Vds<Vgs-Vt to maintain a transistor in linear region.W/L also effect current flow .
 

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