fet configurations
hi, just for homework purposes and out of interest could someone explain the different types of fets and how they work?
I am ok with n channel enhancement - current flow from drain to source when a positive gate voltage is applied with respect to the source voltage. could someone explain n channel depletion and p channel enh and depletion?
A depletion N-channel MOSFET behaves like a JugFET, it's normally on and you need a negative voltage with repect to the source to turn it off. The P-channel device is the same but with the polarity reversed.
The difference between a depletion MOSFET and a JugFET is the former has a metal oxide insulating layer between the gate and channel and the latter does not.
Field-effect transistor - Wikipedia, the free encyclopedia
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so to clarify...
n channel enh - +ve Vgs to turn fet on, fet is normally off, current from drain to source
n channel dep - -ve Vgs to turn fet off, fet is normally on, current from drain to source
p channel enh - +ve Vgs to turn fet on, fet is normally off, current from source to drain
p channel dep - -ve Vgs to turn fet off, fet is normally on, current from source to drain
is this correct?
Yes, that's correct, assuming conventional current flow.
I do not answer private messages asking for help because no one else can: benefit from advice I may give or correct me if I'm wrong.
Please ask on the open forum if you have a question and I'll be happy to help, if I know the answer.
Hi, I just did a simulation on these fets and agree with the first two, however for p channel enh i get current from source to drain, but a -ve vgs turns the fet on, not a +ve. fig 5 on page 5 of this link seems to agree with this point
http://www.nxp.com/acrobat_download/...T100_CNV_2.pdf
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