Introduction to Crystal Diodes 2

4. Frequency characteristics

Due to the presence of junction capacitance, when the frequency reaches a certain level, the capacitance impedance is small enough to short-circuit the PN junction. Causing the diode to lose unidirectional conductivity and fail to operate, the larger the PN junction area, the larger the junction capacitance, and the less it can operate at high frequencies.

2、 Simple testing method for diodes

The polarity of a diodes is usually marked on the casing. If there is no marking, its forward and reverse resistance can be measured using a multimeter in the resistance range to determine (usually using R × 100 or × 1K range)

3、 Main parameters of diodes

1. Forward current IF

At rated power, the current value allowed to pass through the diodes.

2. Forward voltage drop VF

The voltage drop generated between the two poles of a diode when passing through its rated forward current.

3. Maximum rectified current (average) IOM

The average maximum allowable half wave current in the case of continuous operation of half wave rectification.

4. Reverse breakdown voltage VB

The reverse current of the diodes increases sharply to the reverse voltage value at which breakdown occurs.