Detection Method for Three Terminal Schottky Diodes

Detection Method for Three Terminal Schottky Diodes

When there is a problem with the Schottky diode circuit, it is necessary to judge the quality of the Schottky diode. How can we judge the quality of the Schottky diode at this time? The withstand voltage of Schottky Diodes is often low, but their recovery speed is fast and can be used in high-frequency applications. Below, we will explain the methods for measuring the quality of Schottky diodes.

Detection of three terminal Schottky Diodes:

The three terminal Schottky diode should first measure its common terminal to determine whether it is a common cathode pair or a common anode pair, and then measure the forward and reverse resistance values of the two diodes separately. Taking the testing of two Schottky Diodes with a common cathode pair  and a common anode pair  as examples, the specific detection method is explained by labeling the pins as 1, 2, and 3, and placing the multimeter in "R × Perform the following three step test on gear 1.

Step 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 single conductivity.

Step 2: Connect the black lead to pin 1 and the red lead to pin 2. If the measured resistance value is infinite, then switch the red and black lead to measure. If the measured resistance value 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.

Step 3: Connect the black lead to 3 pins and the red lead to 2 pins. If the measured resistance value is infinite, replace the red and black lead and measure. If the measured resistance value is 2.5~3.5 Ω, it indicates that pins 2 and 3 have unidirectional conductivity, and pins 2 are positive. Based on the measurement results of the above three steps, it can be determined that the Schottky diode being tested is a common anode pair , with pins 2 being a common anode and pins 1 and 3 being two cathodes; On the contrary, it is a common negative pair of s.

So, how to judge the quality of a Schottky diode when it cannot be removed? There are also two methods for detection.

1. The voltage at the output end of the Schottky Diodes can be measured by turning on the power supply. If it is abnormal or there is no voltage output, it indicates that the Schottky diode is faulty.

2. It is also possible to measure the forward and reverse resistance of a single Schottky diode without being charged. This Schottky diode with a small difference in forward and reverse resistance is problematic.