Diode parameters

The parameters of a diode are a quantitative description of its characteristics and limiting application conditions, and are an important basis for the correct selection and rational use of diodes in circuit design. In order to ensure the normal and safe operation of the diode, the following main parameters should be considered when selecting the diode.

(1) Maximum rectification current I (F)

I (F) refers to the maximum forward average current allowed to pass through a diode during long-term operation. Its size is determined by the junction area and heat dissipation conditions of the PN junction. In actual use, the average current passing through the diode should be less than I (F). If the actual working current exceeds this value, the diode will be damaged due to excessive heating.

(2) Maximum reverse working voltage U (RM)

U (RM) refers to the maximum allowable reverse voltage applied to both ends of the diode. To avoid reverse breakdown of the diode, the maximum reverse operating voltage U (RM) is usually half of the reverse breakdown voltage U (BR).

(3) Reverse current I (R)

I (R) refers to the reverse current at room temperature when a specified reverse voltage is applied to both ends of a diode. The smaller the value, the better the unidirectional conductivity of the diode. Reverse current is very sensitive to temperature.

(4) Maximum operating frequency f (M)

F (M) is the upper limit frequency of diode operation. When the operating frequency is greater than f (M), the diode will lose unidirectional conductivity due to the action of junction capacitance.