JFETs, or Junction Field Effect Transistors, are a particular type of transistor which primarily function as electronic switches, amplifiers, or impedance matchers. The key eLEMent that differentiates JFETs from other transistors is that they are voltage-controlled, which allows them to deliver high input impedance. This aspect results in minimal energy loss, making them ideal for certain electronic applications where efficiency is paramount. They are very useful in diverse applications such as buffer amplifiers due to their high input resistance, analog switches, constant-current sources, and voltage-controlled resistors.
JFETs are designed specifically for a wide range of applications, tailored to meet the requirements of each operation they are deployed in. This includes audio amplifying circuits, instrumentation, electronic music, and measurements, to name a few. One of the main characteristics of JFETs is that they have a lower gate leakage current, which provides a better performance in high-frequency applications. Renowned manufacturers of JFETs include Texas Instruments, ON Semiconductor, Vishay, and Fairchild Semiconductor.