JFET: Juction Feild Effect Transistor
The Field-effect transistor (FET) is a three terminal device used for a many applications , to a large amount, those of the BJT. Field effect transistors offers many good-looking feature for applications in among switching, high input impedance amplifiers, microwave amplifications and integrated circuits.
The junction field-effect transistors (JFET's) can be separated their structure into the following two categories:-
1. N-channel JFET
2. P-channel JFET
JFET consist of an N-type semiconductor bar with two p-type greatly doped regions diffused on opposite sides of its center part. There are two PN junctions are twisted by p-type regions. The spaces between the two jctuions are called a channel. The p-regions of JEFT are attached internally. A single wire drawn out in the form of a terminal called the gate
In 1925, Julius Lilienfeld predicted this JFET.