Zener diode is also called Zener diode. The principle is to use the pn junction reverse breakdown state, the current changes in a wide range but the voltage remains basically unchanged. Zener diodes are graded by breakdown voltage. If you want to get a higher voltage, you can use it in series, which can get a higher output constant voltage. For example, 1N4620 regulated 3.3V, 1N4625 regulated 5.1V, etc., and the power varies from 200mW to 100W.
The forward characteristic of the volt-ampere characteristic curve of a Zener diode is similar to that of an ordinary diode. The reverse characteristic is that when the reverse voltage is lower than the reverse breakdown voltage, the reverse resistance is large and the reverse leakage current is extremely small. However, when the reverse voltage approaches the critical value of the reverse voltage, the reverse current suddenly increases, which is called breakdown. At this critical breakdown point, the reverse resistance suddenly drops to a very small value. Although the current changes in a large range, the voltage across the diode is basically stable near the breakdown voltage, thus realizing the diode's voltage stabilization function.
The main parameters of the Zener diode: Uz (stabilized voltage refers to the stable voltage value generated at both ends of the Zener tube when the rated current is passed), Lz (rated current refers to the current value through the tube when the Zener tube generates a stable voltage), Rz ( Dynamic resistance refers to the ratio of the voltage change at both ends of the Zener tube to the current change), Pz (rated power consumption refers to the allowable temperature rise of the chip), Ir (reverse leakage current refers to the voltage generated by the Zener diode under the specified direction voltage Leakage current), α (temperature coefficient refers to the parameter whose stable voltage value is affected by temperature).
Zener diodes are classified according to breakdown voltage. Because of this characteristic, Zener diodes are mainly used as voltage regulators or voltage reference components. Zener diodes can be connected in series for use at higher voltages, and higher stable voltages can be obtained by connecting them in series. Zener diodes are generally used in surge protection circuits, overvoltage protection circuits in televisions, arc suppression circuits, and series-type voltage regulator circuits.