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mosfet's
(metal oxide semiconducting feild effect transistor)
voltage controled device
has a:
drain equivilant to the collector on a transistor
gate the base
source the emmiter
no current can flow into the gate
its just a new kind of transistor for the most part
differences between transistor:
when it is on, it still conducts slightly (about 0.4V)
this is because it has a slight resistance, whereas a transistor does not
the small resistance it has is given the name Rdson (something about resistance when on (r d s on))
there is a formula for this in the formula sheet
a mosfet will start to conduct when the input voltage is 3V unless the question says otherwise
when ploting a graph of a mosfet, with Vin and I at the drain (Id) the gradient of that line is called gm
Id = gm * (Vin - 3)
gm is called the transconductance
the gm and rdson are propertys of the mosfet
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