Triode region of NMOS transistor

[sungyueh]

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]

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

Amit

 

[Humungus]

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]

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]

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]

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]

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