Difference between zener and diode — SUNMATE

Difference between zener and diode

First, the diode generally works under the forward voltage, and the voltage regulator tube works under the reverse breakdown state. The usage of the two is different;

Second, the reverse breakdown voltage of ordinary diodes is generally above 40V, which can reach hundreds of volts to thousands of volts, and it is not steep in the reverse breakdown section of the volt ampere characteristic curve, that is, the reverse breakdown voltage range is large, and the dynamic resistance is also large. For the voltage stabilizing tube, when the reverse voltage exceeds its working voltage Vz (also called zener voltage or stable voltage), the reverse current will suddenly increase, and the voltage at both ends of the device will basically remain constant. The corresponding reverse volt ampere characteristic curve is very steep, and the dynamic resistance is very small. The voltage regulator can be used as voltage regulator, voltage reference, overvoltage protection, level converter, etc.

Product selection

Selection of voltage stabilizing diode: the voltage stabilizing diode is generally used as the reference voltage source in the voltage stabilizing power supply or as the protection diode in the over-voltage protection circuit.

The selected zener diode shall meet the requirements of main parameters in the application circuit. The stable voltage value of the zener diode shall be the same as the reference voltage value of the application circuit, and the maximum stable current of the zener diode shall be about 50% higher than the maximum load current of the application circuit.

If the zener diode is damaged, it shall be replaced with a zener diode of the same model or with the same electrical parameters.

A high dissipation power zener diode with the same stable voltage value can be used to replace a low dissipation power zener diode, but a low dissipation power zener diode cannot be used to replace a high dissipation power zener diode. For example, 0.5W and 6.2V zener diodes can be replaced by 1W and 6.2V zener diodes.