How to test whether the Schottky diode is damaged?

How to test whether the Schottky diode is damaged?

Schottky diodes are indispensable in electronic materials. They often encounter damage problems during use. Anyone who knows Schottky diodes knows that its withstand voltage is relatively low, and its recovery speed is relatively fast. , so it often appears in high-frequency occasions. So how to test whether the Schottky diode is damaged?

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

One method is to connect the power supply to measure its output voltage. If the voltage output or the output voltage is abnormal, it is damaged.

The two methods can measure the forward and reverse resistance of the Schottky diode under the condition of no charge. If the resistance difference is small, there is a problem.

2. The quality detection of the two-terminal Schottky diode

The easiest way to measure this kind of Schottky diode is to use a digital multimeter, put the multimeter in the "R×1" block for detection, connect the black test lead to the positive pole, and the red test lead to the negative pole. Normally, its forward resistance value is 2.5~3.5Ω, and its reverse resistance value is infinite. If the measured forward and reverse resistance values are both infinite or close to 0, it means that the Schottky diode is open circuit or has been broken down and damaged.

3. Good or bad detection of three-terminal Schottky diode

This kind of tube is a bit different from the previous two. For this kind of Schottky diode, its common terminal should be measured first to identify the common cathode or common anode pair of tubes, and then measure the forward and reverse resistance of the two tubes. Let's take a common cathode pair tube and a common anode pair tube as an example to explain how to detect it in detail. First, mark the pins as l, 2 and 3 respectively, and place the multimeter in "R×1" '' block to perform the following three-step test.

①. Measure the positive and negative resistance of pins 1 and 3. If it is infinite, it means that the two electrodes have no unidirectional conductivity.

②. Connect the red test lead to pin 2, and connect the black test lead to pin 1. If the result is infinite, exchange the black and red test leads for detection. If the measured result is 2.5~3.5Ω, it means that pins 2 and 1 have One-way conduction characteristics, and 2 pins are positive, 1 pin is negative.

③. In the last step, connect the red test lead to pin 2 and the black test lead to pin 3. If the result is infinite, replace the black and red test leads for detection. If the measured result is 2.5~3.5Ω, it means pins 2 and 3 It has unidirectional conduction characteristics, and pin 2 is positive and pin 3 is reverse. According to the above three measurement results, we can judge that the Schottky diode is a common anode pair, in which pins 1 and 3 are two cathodes, and pin 2 is a common anode. On the contrary, it is a common cathode pair tube.