Junction Field Effect Transistor

A Junction Field Effect Transistor (JFET) is a three-terminal semiconductor device that controls current flow through a channel using an electric field. Unlike bipolar transistors, JFETs are voltage-controlled devices where the gate voltage controls the conductivity of the channel between the source and drain terminals. They are normally-on devices that conduct current when no gate voltage is applied, and current decreases as reverse gate voltage increases. JFETs are commonly used in low-noise amplifiers, analog switches, and high-input impedance circuits due to their minimal gate current requirements.