JFETs

Junction gate field-effect transistors (JFET) are devices used as electronically-controlled switches, amplifiers, or voltage-controlled resistors. A potential difference of the proper polarity applied between the gate and source terminals increases resistance to current flow, which means less current would flow in the channel between the source and drain terminals. JFETs do not need a biasing current due to a charge flowing through a semiconducting channel between source and drain terminals.