October 1, 2011

Field Effect Transistor (FET)

Field effect transistor is also called as unipolar transistor. FET uses either electrons, in N-channel FET, or holes in P-channel FET for conduction. Field effect transistor has four main electrodes: source, gate, drain and substrate. In general, the body of the FET is connected to the source inside the package.
Field Effect transistor ( FET ) has two types, the Junction Field Effect Transistor ( JFET ) and Insulated Gate Field Effect Transistor ( IGFET ). IGFET is also called as MOSFET which stands for Metal Oxide Semiconductor Field Effect Transistor, replicating its original structure from sheets of metal — which is the gate, oxide — the insulation, and semiconductor. On the other hand JFET gate forms a PN diode with the channel which lies in the middle of the source and drain.