The working principle and characteristics of varactor diodes 1

Varactor diode, also known as a capacitive diode, is a special type of diode that has the characteristic of variable capacitance. Its working principle is based on the reverse bias of the PN junction, which changes the capacitance value by altering the reverse voltage. Varactor diodes are widely used in RF circuits, CY7C63310-SXC oscillators, filters, and other fields. Their functions and characteristics are as follows:

1. Working principle:

The working principle of a varactor diode is based on the reverse bias of a PN junction. When the varactor diode is in reverse bias, the forward current (injection current) is almost zero, and under reverse voltage, a reverse bias electric field is formed. When the reverse voltage increases, the strength of the reverse bias electric field increases, causing the depletion region of the PN junction to widen and the capacitance value to decrease.diode  On the contrary, when the reverse voltage decreases, the depletion region narrows and the capacitance value increases. By changing the reverse voltage, the capacitance value of the varactor diode can be adjusted.