How to test if Schottky diodes are damaged?

How to test if Schottky diodes are damaged?

Schottky diodes are indispensable in electronic materials and often encounter damage problems during use. Those who understand Schottky diodes know that their voltage resistance is relatively low, and their recovery speed is relatively fast. Therefore, they often appear in high-frequency situations. So how to test if the Schottky diode is damaged?

1. How to determine the quality of Schottky diodes when they cannot be removed for inspection?

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

There are two methods to measure the forward and reverse resistance of Schottky diodes without charging, and the difference in resistance indicates a problem.

2. Quality detection of two terminal Schottky diodes

The simplest way to test this Schottky diode is to use a digital multimeter. Place the multimeter in the "R × 1" position and connect the black probe to the positive terminal and the red probe to the negative terminal. Normally, its forward resistance value is 2.5~3.5 Ω, and its reverse resistance value is infinite. If both the forward and reverse resistance values are infinite or close to 0, it indicates that the Schottky diode has opened or been damaged by breakdown.

3. Quality detection of three terminal Schottky diodes

This type of diode is a bit different from the first two. For this Schottky diode, its common terminal should be measured first to distinguish between the common cathode or common anode pair, and then the forward and reverse resistance values of the two diodes should be measured. Taking a co negative and a co positive pair of diodes as examples, we will explain how to detect them in detail. First, label the pins as l, 2, and 3 respectively, and place the multimeter in the "R × 1" position for the following three steps of testing.

① Measure the forward and reverse resistance values of pins 1 and 3. If they are infinite, it indicates that these two electrodes have no unidirectional conductivity.

② Connect the red probe to pin 2 and the black probe to pin 1. If the result is infinite, swap the black and red probes for testing. If the measured result is 2.5-3.5 Ω, it indicates that pins 2 and 1 have unidirectional conductivity, and pin 2 is positive and pin 1 is negative.

③ The final step is to connect the red probe to pin 2 and the black probe to pin 3. If the result is infinite, swap the black and red probes for testing. If the measured result is 2.5-3.5 Ω, it indicates that pins 2 and 3 have unidirectional conductivity, and pin 2 is positive and pin 3 is negative. Based on the above three measurement results, we can determine that the Schottky diode is a common anode pair, with pins 1 and 3 being two cathodes and pin 2 being a common anode. On the contrary, it is a common negative diode