Field Effect Transistor (FET): A Core Component of Modern Electronics
A Field Effect Transistor (FET) is a type of transistor that uses an electric field to control the flow of current. Widely used in amplifiers, switches, and integrated circuits, the FET is fundamental to today’s electronic devices, from smartphones and computers to industrial equipment.
What Is a Field Effect Transistor?
Unlike a Bipolar Junction Transistor (BJT), which relies on current flow between two junctions, a FET controls current using voltage applied to its gate terminal. This voltage creates an electric field that regulates the conductivity of a semiconductor channel, allowing or preventing current flow between the source and drain terminals.
Main Types of FETs
Junction FET (JFET):
Simple structure with a gate junction that controls current.
Known for high input impedance and low noise, ideal for amplifiers.
Metal-Oxide-Semiconductor FET (MOSFET):
The most common type, used extensively in digital circuits and power applications.
Offers fast switching speeds and excellent energy efficiency.
Depletion and Enhancement Modes:
Depletion-mode FETs conduct by default and require a gate voltage to turn off.
Enhancement-mode FETs require a gate voltage to conduct, common in logic circuits.