Designation System
Examples of Pro Electron type designators are:
- AD162 -- germanium power transistor for audio frequency use
- BY133 -- silicon rectifier
- BZY88C5V1—5.1V -- silicon Zener diode
- CQY97 -- light emitting diode
- ECC83 -- 6.3V heater noval dual triode
- A63EAA00XX01 -- Color TV picture tube
- SAA1300 -- Digital integrated circuit
Pro Electron took the popular European coding system in use from around 1934 for valves (tubes), i.e. the Mullard–Philips tube designation, and essentially re-allocated several of the rarely-used heater designations (first letter of the part number) for semiconductors. The second letter was used in a similar way to the valves naming convention: "A" for signal diode, "C" for low-power bipolar transistor or triode, "D" for high power transistor (or triode), and "Y" for rectifier, but other letter designations did not follow the vacuum tube mode so closely.
The three digits (or letter followed by two digits) after the first two letters were essentially a sequence number, with (at first) a vestige of the valve-era convention that the first one or two digits would indicate the base (package) type in examples such as:
| Package | NPN | PNP |
|---|---|---|
| TO-18 | BC10x | BC17x |
| Lockfit | BC14x | BC15x |
| TO-92 | BC54x | BC55x |
... where x may be:
- 7 for high-voltage
- 8 for general purpose
- 9 for low noise/high gain
Pro Electron naming for transistors and Zener diodes has been widely taken up by semiconductor manufactures around the world. Pro Electron naming of integrated circuits, other than some special (e.g. television signal-processing) chips, did not greatly take hold (even in Europe). Other popular designation systems were used for many integrated circuits.
Read more about this topic: Pro Electron
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