Secrets Of Zener diode datasheet, part number or marking.

A 2.4 Volt zener diode

Zener diode datasheet meaning is a little bit different from marking, reference or code. Quite a numbers of engineers and technicians are confused on how to read a zener diode part number or data. There are many types of specification or code number indicated on its body. The outlook and shape of a zener diode sometimes can be mistaken to be a normal 1n4148 signal diode. To know whether it is a zener diode or just a normal diode, you need to read the identification or markings on its body.

Thanks to the manufacturers because the main boards were printed 'ZD' which mean zener diode and 'D' means a diode. However, from my experienced, some printed circuit board the marking of 'D' also can represent zener diode.

This situation will misguided a technician into believing a zener diode is actually a diode. We as a electronic repairer must know or be sensitive about the marking values and ratings.

The only way to find out is by referring the part number printed on the component's body from a replacement guide book. Without data book it is very tough for us to know the actual zener diode voltage. If you do not have the semiconductor or replacement data book you may go to any search engine and type the following code for reference and hope you can find the answer there!

A wrong part number installed may cause your equipment to malfunction and behave strangely. Precious time and money were loss due to that we lack of knowledge in zener diode spec identification. If you can’t find out what is the code or part number mean then it is very difficult to repair the equipment. Do not worry as this website here is to guide you to successfully on how to read the zener diode marking. 

2.4=2.4 Volt zener diode

2V4=2.4 Volt

10= 10 Volt

10V= 10 Volt

BZX85C18=18 Volt 1 watt zener diode (you have to refer to Philips ECG Semiconductors Transistor Cross Reference Guide)

BZY85C18=18 Volt 1/2 watt zener diode

Note: There is also part number such as BZVXXXXX where you have to find it from Philips ECG SEMICONDUCTOR BOOK.

1N4746= 18 Volt 1 watt zener diode

6C2=6.2 Volt zener diode. (If you observe the zener diode code, it is written as 6C2 READING FROM TOP TO BOTTOM)

Don't read from bottom to top otherwise the value you get is 2C6 which you will not find it in any data book!

Many of you will ask how I find the voltage for the code of 6C2. Still you have to refer to Philips replacement guide book; you have to search for HZ cross reference first. That's mean instead of finding 6C2; search for HZ6C2 and you will find the answer! The lowest voltage that I came across was 2.4 volt and the highest was 200 Volt 5 watts. Monitor power supply section usually used zener diode in the range of 18 volt to 30 volt. 

Conclusion- Be aware when checking the part number of a zener diode. Don't always assume that a small signal diode glass type is a zener diode. Remember, the newer version of signal diode 1n4148, some manufacturers marked it as ‘48’ and you thought is 48 volt. Carefully see the marking on the main board whether is ‘zd’ or‘d’. Search the internet for zener diode datasheet, data and part number and get a Philips ECG master replacement guide book for reference. With the knowledge you gained above, you will definetely have no problem in identifying the right voltage for a zener diode and able to repair the equipment.