A Zener diode is a type of semiconductor diode that is different to a normal diode as it allows current to flow from its anode to its cathode in either a forward or reverse direction, but only when exposed to enough voltage. Zener diodes have been designed to work reliably in the breakdown region, unlike normal diodes which would overheat. They are the most common and the handiest solutions to a number of needs in a circuit design. Zener diodes are designed to change the direction of current flow once the voltage reaches a specific, defined voltage level. This also means that Zener diodes can operate continuously in a breakdown mode. The voltage level that that change a direction of flow is called Zener Voltage or Breakdown Voltage. It could be defined for specific diodes anywhere from 1.8 to 200 V.Key attributes of a Zener diode are:• Device configuration including a dual or common anode• Type of Zener, including avalanche or voltage regulator• Voltage tolerance• Voltage drift with temperature• Impedance (max)What is a typical application of Zener diodes? Zener diodes are used in all kinds of electronic equipment and are used to protect circuits from overvoltage and electrostatic discharge or for switching applications. They are one of the basic building blocks of electronic circuits.