JFET

Overview

The junction field-effect transistor (JFET) is the simplest type of field-effect transistor. They are three-terminal semiconductor. JFETs are voltage-controlled. Electric charge flows through a semiconducting channel between source and drain terminals. By applying a reverse bias voltage to a gate terminal, the channel is "pinched", the electric current is switched off completely. A JFET is usually on when there is no potential difference between its gate and source terminals. If a potential difference of the proper polarity is applied between its gate and source terminals, the JFET will be more resistive to current flow. JFETs are sometimes referred to as depletion-mode devices.