What is a zener diode? Let's have a look
Zener diode, also known as zener diode in English, is a diode for stabilizing voltage by using the reverse breakdown state of PN junction, the current can change in a large range and the voltage is basically unchanged.
The diode is a semiconductor device with high resistance until the critical reverse breakdown voltage At this critical breakdown point, the reverse resistance decreases to a very small value. In this low resistance region, the current increases and the voltage remains constant. The zener diode is divided according to the breakdown voltage. Because of this characteristic, the zener tube is mainly used as a voltage regulator or voltage reference element. Zener diodes can be connected in series for use at higher voltage. Higher stable voltage can be obtained by connecting in series.
The characteristic of Zener diode is that the voltage at both ends remains basically unchanged before reverse energization and breakdown. In this way, when the voltage stabilizing tube is connected to the circuit, if the voltage at each point in the circuit changes due to power supply voltage fluctuation or other reasons, the voltage at both ends of the load will basically remain unchanged. Zener diode is usually represented by 'ZD' plus numbers in the circuit. For example, zd5 represents the zener tube numbered 5. （ShenMeShiWenYaErJiGuan）