Testing Schottky Diode- The Right Way To Test It.
is schottky diode or schottky barrier rectifiers are designed for high efficiency rectification essential for applications like Switched mode power supplies (SMPS), Switching regulator and etc. If you look at electronic schematic diagram, schottky diode symbol looks the same as normal diode. Even the shape and designed just like a normal diode. The major differences between a normal diode and schottky diode is the part number. Due to this, many technicians thinks that checking schottky diode just the same as checking a normal diode. Infact there is a right method to identify schottky diode and a suggested way to test it.
Searching the internet for the diode schottky part number and browsing through the semiconductor replacement guide can quickly give you the answer whether the component that you are testing is a normal diode, ultra fast recovery diode or schottky diode. If you have confirmed that the diode is a schottky diode then you you have to use the accurate way to test it.
Set your analog multimeter to times 10k ohm. Place the red probe to the cathode and the black probe to the anode. You should see the needle goes up to full scale. Reversing the probe will show some leakage which mean the needle move up a little bit. This is a good schottky diode characteristic when checking on it. However if you measure a normal diode and you discovered that it has two readings then the diode is considered spoilt and need to replace. A shorted schottky barrier diode will show two full scale readings registered at the panel meter.
is a technician do not know how to check a schottky diode, he or she may think that the diode have some leakage and need to replace. The worst part is diodo schottky is not easy to find in the market. Searching for schottky diode replacement will take you time and it is not necessary if you know how to test it. The technician might just simply replace a 'normal diode' and hope that it will work. Well, the equipment will still not work because you have replaced a working diode (schottky diode) with another good diode! The actual culprit is still out there and not the schottky diode.
Sometimes replacing a schottky diode with a normal diode may cause the equipment to be unstable especially in the sensitive circuit. The best is to replace with original number or a specification that is higher than the original diode. Typical part number for a schottky diode is 1N5819. Go check out this part number from your favorite search engine and semiconductor data book.
That's it for this issue my friend. Thank you for reading. I will send you more tips. Until then, here's wishing you all the best in electronic repair.
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