Zenerdiodit

Zenerdiodit (Zener diode) is a diode designed to conduct in reverse when the applied voltage reaches a specified breakdown voltage. It is widely used for voltage regulation and as a reference voltage in electronic circuits.

In operation, a Zener diode is reverse-biased and clamps the voltage across itself at approximately its Zener voltage, Vz. The breakdown occurs primarily via the Zener effect in heavily doped p-n junctions at relatively low voltages and via avalanche breakdown at higher voltages; in practice, many diodes rely on a combination of both to achieve a stable voltage.

Key characteristics include a rated breakdown voltage (Vz), tolerance, and dynamic resistance. The current through the diode must stay within a specified operating range to maintain regulation; outside that range the voltage regulation worsens. Temperature also affects the Zener voltage, with the temperature coefficient varying with Vz and device design.

Applications of Zenerdiodit include shunt voltage regulation, where the diode maintains a stable reference across load changes, voltage references for power supplies and integrated circuits, and overvoltage protection. They are also used in various signaling and protection circuits, sometimes in transient voltage suppressor configurations with unidirectional or bidirectional variants.

History and variants: the device is named after Clarence Zener, who described the breakdown mechanism in 1934. Modern Zener diodes come in various sizes and voltage ratings, from a few volts to hundreds of volts, and serve as compact, inexpensive references and regulators in consumer electronics, industrial equipment, and instrumentation.