How to Read Zener Diode Code

Many technicians are confused on how to really readBZX85C22=22Volt 1 watt zener diode (refer to ECG
a zener diode code. There are many types of codePHILIPS SEMICONDUCTORS MASTER
number indicated on it's body. The look and shape of aREPLACEMENT GUIDE)
zener diode sometimescan be mistaken to be aBZY85C22=22Volt 1/2 watt zener diode (refer to
normal signal diode. To differentiate it, is by looking atECG PHILIPS SEMICONDUCTORS MASTER
the codenumber on it's body- whether it is a normalREPLACEMENT GUIDE)
diode or zener diode. Thanks to the manufacturersNote: There is also part number such as BZVXXXXX
where their main boards are printed with the word 'ZD'where you have to find it from ECG
which referred to zener diode and 'D' means a diode.SEMICONDUCTOR BOOK.
However, from my experienced some printed circuit1N4746= 18 Volt 1 watt zener diode (refer to ECG
board the marking of 'D' also can represent zenerPHILIPS SEMICONDUCTORS MASTER
diode. This will misled a technician into believing a zenerREPLACEMENT GUIDE)
diode is actually a diode. We as a technician or6C2=6.2 Volt zener diode. (If you look at the zener
engineer must know or be sensitive about the marking.diode code it is written as 6C2 READING FROM TOP
The only way to find out is by referring the codeTO BOTTOM) Don't read from bottom to top
number printed on the component's body from aotherwise the value you get is 2C6 which you cannot
semiconductor data book. Without data book it is quitefind from data book!
difficult to know the actual zener diode voltage. If youI believe many will ask how do I get the voltage for the
do not have the data book you may go to googlecode of 6C2. Still refer to ECG book, you have to
search engine and type the following code and hopesearch for HZ part number. That's mean instead of
you can find the answer there! A wrong substitution offinding 6C2, search for HZ6C2 and you will get the
zener diode may caused your equipment toanswer! The lowest zener voltage that I came across
malfunction and sometimes will even blow yourwas 2.4 volt and the highest was 200 Volt 5 watt.
equipment. Time and money are loss due to that weConclusion- Be alert when checking the part number
lack of knowledge of identify the right zener diodeof a zener diode. Don't always assume that a small
voltage. If you are unable to identify the code, do notsignal diode is always a zener diode. Carefully observe
worry as this newsletter are here to guide you tothe marking on the main board and read the zener
successfully on how to read the zener diode code.diode part number refer to the semiconductor book,
5.1=5.1Volt zener diodepreferably ECG SEMICONDUCTOR DATA BOOK
5V1=5.1Volt zener diodewhich you can get from your local electronic distributor.
12= 12 Volt zener diodeWith this knowledge in mind, you will be successfully
12V= 12 Volt zener diodefind the right voltage of a zener diode.