PMOS trans-conductance formula

Thread Starter

Kai Chiang

Joined Oct 27, 2015
12
This is the formula in my lecture note for NMOS
upload_2016-9-2_17-57-18.png]
for PMOS, is it something like this? I cant seem to find PMOS formula for this on the internet. Most of them shows the one in my lecture note
upload_2016-9-2_17-58-49.png
where |Vgs| = Vsg and |Vth| is VTHP
which is upload_2016-9-2_18-0-36.png
 

MrAl

Joined Jun 17, 2014
8,503
Hi,

The only difference i've seen so far is the subscripts they use:
Wn, Ln for NMOS
Wp, Lp for PMOS
IDn for NMOS
-IDp for PMOS (different sign)

I think gm is positive for both because the gate voltage is probably considered negative too for PMOS, but you can check into this.
 
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