
Selection of voltage stabilizer diode
For a steady voltage diode, when the reverse voltage exceeds its working voltage Vz (also called zener voltage or stable voltage), the reverse current will increase suddenly, and the voltage at both ends of the device is kept constant. The corresponding reverse volt ampere characteristic curve is very steep, and the dynamic resistance is very small. The voltage regulator diode is usually used as a reference voltage source in a regulated power supply, or as a protective diode in overvoltage protection circuit.
The voltage regulator diode should meet the requirements of the main parameters in the application circuit. The stable voltage of the voltage regulator should be the same as the reference voltage of the applied circuit. The maximum stable current of the voltage regulator diode should be higher than 50% of the maximum load current of the application circuit.
After the diode is damaged, we should use the same type diode or the same voltage regulator diode to replace it. The high dissipative power regulated diode with the same stable voltage value can be used to replace the low power diode with low dissipative power, but it can not be used to replace the high dissipation power diode with low power dissipation diode. For example, the zener diodes of 0.5W and 6.2V can be replaced by 1W and 6.2V voltage stabilizing diodes.