# Zener diode

Zener-diode

> a form of semiconductor diode in which at a critical reverse voltage a large reverse current can flow.

![](https://2889346953-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-Le4Kw7maZEabKFjsC7z%2F-Lf5hWWAPXrS6pkg310z%2F-Lf5hjf_wOah0rJFWJRy%2Fzener-diode-characteristic.png?generation=1558112049609226\&alt=media)

Zener diodes are made to conduct under reversed bias. Zener diodes are fabricated to work in the breakdown region under a special tunneling breakdown called Zener breakdown. This breakdown occurs at a specifically defined value of voltage, as this breakdown voltage is maintained as the reverse current increases, this diode can be used as a voltage reference. The breakdown voltage is kept constant even if the cur- rent changes without damaging the diode.

The main property of a zener diode is that the voltage across the diode ($$V_Z$$) will remain practically steady for a wide range of current ($$I_Z$$) when the diode is operated in reverse bias mode:

![](https://2889346953-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-Le4Kw7maZEabKFjsC7z%2F-Lf5hWWAPXrS6pkg310z%2F-Lf5hjfdYvbipW1HmLAq%2Fzener-diode-circuit.png?generation=1558112045884727\&alt=media)
