Schottky diode performance testing method

Schottky diode is also called Schottky barrier diode (SBD). It is a low-power, ultra-high-speed semiconductor device, which is widely used in switching power supplies, inverters, drivers and other circuits for high-frequency, Low-voltage, high-current rectifier diodes, freewheeling diodes, protection diodes, or used as rectifier diodes and small-signal detector diodes in microwave communication circuits.

Performance comparison:

The following table lists the performance comparison of Schottky diodes and ultra-fast recovery diodes, fast recovery diodes, silicon high-frequency rectifier diodes, and silicon high-speed switching diodes. It can be seen from the table that although the trr of silicon high-speed switching diodes is extremely low, the average rectified current is very small and cannot be used for high-current rectification.
Detection method

Here is an example to introduce the method of detecting Schottky diodes. The testing content includes: ①Identify the electrode; ②Check the unidirectional conductivity of the tube; ③Measure the forward voltage drop VF; ④Measure the reverse breakdown voltage VBR.

The tested tube is a B82-004 Schottky tube, which has three pins. The pins are numbered ①, ②, and ③ from left to right according to the front (literally facing the person). Select the R×1 file of the 500-type multimeter for measurement, and arrange all the data into the following table:

Schottky diode test conclusion:

First, according to the forward resistance between ①-② and ③-④, it is judged that the tube under test is a common cathode pair tube, the pins ① and ③ are two anodes, and the pin ② is the common cathode.

Second, because the forward resistance between ①—② and ③—② is only a few ohms, and the reverse resistance is infinite, it has unidirectional conductivity.

Third, the forward voltage drops of the two internal Schottky diodes are 0.315V and 0.33V respectively, which are lower than the maximum allowable value VFM (0.55V) given in the manual.

In addition, using the 250VDC gear of the ZC 25-3 type megohmmeter and the 500 type multimeter, the reverse breakdown voltage VBR of the two internal tubes is 140V and 135V in sequence. Check the manual, the highest reverse working voltage of B82-004 (ie reverse peak voltage) VBR=40V. Shows that there is a higher safety factor.