In most circuits, this means pulling an enhancement-mode MOSFET's gate voltage towards its drain voltage turns it ON. In a depletion-mode MOSFET, the device is normally ON at zero gate–source voltage. Such devices are used as load "resistors" in logic circuits (in depletion-load NMOS logic, for example).
Two basic configurations of Junction field Effect Transistor are: (i) N-channel Jfet: In n channel jfet’s, channel is generally doped with donor impurities i.e., into this the flow of current through the channel is negative in the form of electrons.
MOSFET (metal-oxide semiconductor field-effect transistor, pronounced MAWS-feht) is a special type of field-effect transistor ( FET) that works by electronically varying the width of a channel along which charge carriers ( electron s or hole s) flow.