Schottky diode is an indispensable part of electronic materials. It is often damaged in use. People who know about Schottky diode know that its withstand voltage is relatively low and its recovery speed is relatively fast, so it often appears in high-frequency situations. So how to test whether the Schottky diode is damaged?

1. When Schottky diode cannot be removed for inspection, how to judge whether it is good or bad?

One way is to connect the power supply and measure its output voltage. If the output voltage or output voltage is abnormal, it will be damaged.

The two methods can measure the forward and reverse resistance of the Schottky diode when it is not electrified, and the resistance difference Shaw indicates that there is a problem.

2. Detection of the quality of two-terminal Schottky diode

The simplest way to measure this Schottky diode is to use a digital multimeter and set the multimeter at "R × 1 "gear detection, the black lead is connected to the positive pole, and the red lead is connected to the negative pole. Under normal conditions, the forward resistance value is 2.5~3.5 Ω, and the reverse resistance value is infinite. If the measured forward and reverse resistance values are both infinite or close to 0, it indicates that the Schottky diode has been open circuit or broken down.

3. Detection of Three-terminal Schottky Diode

This kind of tube is a little different from the first two. This Schottky diode should first measure its common end, identify the common negative or common positive pair of tubes, and then measure the positive and negative resistance values of the two tubes. Let's take a common negative pair of tubes and a common positive pair of tubes as an example to explain how to detect them. First, mark the pins 1, 2 and 3 respectively, and place the multimeter at "R × Perform the following three steps for 1 '' gear.

① . Measure the forward and reverse resistance values of pins 1 and 3. If it is infinite, it means that there is no single conductivity between these two electrodes.

② . Connect the red lead to 2 pins and the black lead to 1 pin. If the result is infinite, the black and red lead will be interchanged for detection. If the measured result is 2.5~3.5 Ω, it means that pins 2 and 1 have unidirectional conductivity, and pin 2 is positive and pin 1 is negative.

③ The last step is to connect the red lead to 2 pins and the black lead to 3 pins. If the result is infinite, the black and red lead will be exchanged for detection. If the measured result is 2.5~3.5 Ω, it means that the 2 and 3 pins have unidirectional conductivity, and the 2 pins are positive and the 3 pins are negative. According to the above three measurement results, we can judge that the Schottky diode is a common anode pair tube, in which pins 1 and 3 are two cathodes, and pins 2 are common anodes. On the contrary, it is a common anion pair.