| Semiconductor numbering or coding systems |
Transistor and diode numbering systems
- the Pro-electron and JEDEC numbering systems for semiconductors
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 (Proelectron) system, and the one used more widely in North America
is the JEDEC system.
The numbers using the Pro-electron and JEDEC systems have
different formats as seen below:
Pro-Electron Numbering or Coding System
First Letter
Specifies semiconductor material |
Second Letter
Specifies type of device |
Subsequent Characters |
| A |
Germanium |
| B |
Silicon |
| C |
Gallium Arsenide |
| R |
Compound materials |
|
| A |
Diode - low power or signal |
| B |
Diode - variable capacitance |
| C |
Transistor - audio frequency, low power |
| D |
Transistor - audio frequency, power |
| E |
Tunnel diode |
| F |
Transistor - high frequency, low power |
| G |
Miscellaneous devices |
| H |
Diode - sensitive to magnetism |
| L |
Transistor - high frequency, power |
| N |
Photocoupler |
| P |
Light detector |
| Q |
Light emitter |
| R |
Switching device, low power, e.g. thyristor,
diac, unijunction |
| S |
Transistor - switching low power |
| T |
Switching device, low power, e.g. thyristor,
triac |
| U |
Transistor - switching, power |
| W |
Surface acoustic wave device |
| X |
Diode multiplier |
| Y |
Diode rectifying |
| Z |
Diode - voltage reference |
|
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
| First Number |
Second Letter |
Subsequent numbers |
1 = Diode
2 = Bipolar transistor
3 = FET |
N |
Serial
number
of
device |
Thus a 1N914 is a diode and a 2N706 is a transistor.
|
