Zener Diodes are closely related to P–N junction diodes. They are constructed to take advantage of reverse current. Zener diodes find wide
application for controlling voltage in all types of circuits.
ZENER DIODE CHARACTERISTICS
in P–N junction diodes, a high reverse-bias voltage applied to a diode may create a high reverse current, which can generate excessive heat and cause a diode to break down. The applied reverse voltage at which the breakdown occurs is called the breakdown voltage (EZ) or peak reverse voltage. A special diode called a zener diode is connected to operate in the reverse-bias mode. It is designed to operate at those voltages that exceed the breakdown voltage. This breakdown region is called the zener region.