The process of stabilizing a diode

If the reverse voltage of the zener diode is added to a certain high level, the zener diode will pass a large current due to breakdown. However, this phenomenon is exactly what we hope, because this zener diode works in this breakdown state. As long as the voltage regulator diodee works normally, it will always be in this state of breakdown. At this time, the current passing through it is large but the change in the voltage drop of the diodee is very small, so it can play a role in voltage regulation. We also call it a Zener diode. It has the characteristics of forward conduction and reverse cutoff of ordinary diodes. However, when the reverse voltage of this diode exceeds a certain value, breakdown will occur, and this breakdown is soft breakdown and will not cause damage to the diode. The stabilizing function of the zener diode is to utilize its reverse breakdown effect. The inside of the Zener diode is also made of a PN structure. When the PN junction breaks down in reverse and the current changes within a certain range, the voltage will remain basically unchanged.

It can be seen from the volt-ampere characteristic curve of the zener diode that its forward characteristic is consistent with that of ordinary diodes, and its reverse characteristic is similar to that of ordinary diodes when it is lower than its breakdown voltage, and is at cut-off. However, when the breakdown voltage is exceeded, the current will change rapidly, but the voltage will remain within a small range. The basic diode regulator circuit maintains stable operating voltage by connecting it in reverse parallel with the load.