Transistors

A transistor is a fundamental semiconductor device used to amplify or switch electrical signals and power. Typically made of semiconductor material and equipped with at least three terminals, transistors control the flow of current within a circuit. By applying a voltage or current to one pair of terminals, the transistor regulates the current flowing through another pair—enabling signal amplification or switching.

Transistors are essential to modern electronics. As amplifiers, they boost weak input signals into stronger output signals—such as in radios, where faint signals from the air are amplified for playback through speakers. As switches, transistors toggle between on and off states, controlling the flow of current in digital circuits and forming the backbone of computing logic.

While some transistors are used as standalone components, the majority are embedded within integrated circuits (ICs) or large-scale integrations (LSIs), which house thousands or even millions of transistors to perform complex functions in compact, efficient devices. Their ability to both amplify and switch signals makes transistors indispensable to everything from smartphones and computers to automotive and communication systems.