Transistor & Diode Numbering Systems & Codes
- the Pro-electron and JEDEC numbering systems or codes are the msot widely used for transistors, FETs and diodes, although for surface mount components much smaller codes are used to indicate which type of transistor diode of FET it is.
There are two main numbering systems for semiconductor diodes, transistors and FETs.
One numbering or code system is used more widely in Europe and the other in the USA.
The European based system is known as the Pro-electron system, sometimes also written as Proelectron system, and the one used more widely in North America is the JEDEC coding system.
The numbers using the Pro-electron and JEDEC systems have different formats as seen below:
Pro-Electron Numbering or Coding System
|Pro-Electron Numbering or Coding System
for Diodes, Transistors and FETs
Specifies semiconductor material
Specifies type of device
||The characters following the first two letters form the serial number of the device. Those intended for domestic use have three numbers, but those intended for commercial or industrial use have letter followed by two numbers, i.e. A10 - Z99.|
From this it can be seen that a BC109 is a low power audio transistor and a BBY13 is variable capacitance diode for industrial or commercial use.
JEDEC Numbering or Coding System
|JEDEC Numbering or Coding System
for Diodes, Transistors & FETs
|First Number||Second Letter||Subsequent numbers|
| 1: Diode
2: Bipolar transistor
|N||Serial number of device|
Thus a 1N914 is a diode and a 2N706 is a transistor.
By Ian Poole
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