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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.
 

amitbhaiji

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

Amit
 

Humungus

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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.
 

rfsystem

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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.
 

shanmei

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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!
 

driveforce

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shanmei said:
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?
 

najmuus

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

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