Pro Electron/EECA is the European type designation and registration system for active components (such as semiconductors, liquid crystal displays, sensor devices, electronic tubes and cathode ray tubes).
The goal of Pro Electron is to allow unambiguous identification of electronic parts, even when made by several different manufacturers. To this end, manufacturers register new devices with the agency and receive new type designators for them.
Examples of Pro Electron type designators are:
- AD162 – Germanium power transistor for audio frequency use
- BY133 – Silicon rectifier
- BZY88C5V1 – Silicon 5.1 volt Zener diode
- CQY97 – light emitting diode
- ECC83 – 6.3 volt 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 in this family of general-purpose transistors:
... 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.
Differences between Pro Electron and earlier valve-naming conventions
- Unlike the tube naming convention, if there are two transistors in a single envelope, the type letter was never repeated - so a dual NPN RF transistor might get a type "BFM505" rather than something like "BFF505" for instance.
- Although some of the most popular devices conform to a pattern of serial numbers that identified package type and polarity, many do not.
- The letters assigned for the second character of transistor and diode type numbers differ in several ways, e.g.
- "B" tends to be used for dual varicap diodes
- "L" in the context of transistors designates RF power (transmitting) transistors; for valves it meant a high-power pentode tube (the usual choice for power RF)
- "Z" is used for semiconductor Zener diodes instead of (full-wave) rectifier valves (tubes).
Frequently used first letters in European active devices
- A Germanium (or any semiconductor with junctions in a material with a band gap of 0.6 to 1.0eV)
- B Silicon (or band gap of 1.0 to 1.3eV)
- C III-V semiconductors with a band gap of 1.3eV or more, like gallium arsenide in LEDs
- D may be...
- E (Mullard–Philips) tubes with a 6.3V heater
- F Digital integrated circuits
- P (Mullard–Philips) tubes for a 300mA series heater supply
- R Devices without junctions, e.g. cadmium sulfide in a photoresistor
- S Solitary digital integrated circuits
- T Linear integrated circuits
- U may be...
- (Mullard–Philips) tubes for a 100mA series heater supply, or
- Mixed digital/analogue integrated circuits
- See Mullard–Philips tube designation for details. A brief summary of just the more common letters is:
ECC81 / \ \\__ last digit(s) give serial number / \ \__ first digit(s) indicate base (3=octal, 8 or 18 or 80=Noval (B9A), 9=Miniature 7-pin (B7G). / \___ one letter per valve unit in the tube: D=1.4v or less A=single-diode (low power) E=6.3v* B=double-diode (usually shared cathode, but not always) P=300mA C=triode U=100mA F=pentode (low power) L=pentode (high power) Y=Single-phase rectifier Z=Full-wave rectifier * Note: some 6.3 volt heater types have a split heater allowing series (12.6 volt; the default for Noval pins 4 to 5) or parallel (6.3 volt) operation.
Semiconductor diodes and transistors
As listed above, the first letter gives the semiconductor type; the second letter denotes the intended use:
|A||Low-power/small-signal diode||AA119, BA121|
|C||Small signal transistor, RthG > 15K/W||BC546C|
|D||High-power, low-frequency power transistor, RthG ≤ 15K/W||BD139|
|F||Low-power, RF (high-frequency) bipolar or FET, RthG > 15K/W||BF245|
|G||Hybrid device||BGY32, BGY585|
|L||High-frequency, high-power transistor (for transmitters), RthG ≤ 15K/W||BLW34|
|M||Ring modulator-type frequency mixer|
|P||Radiation detector (photodiode, phototransistor)||BPW34|
|Q||Radiation generator (LED)||CQY99|
|R||Low-power control or switching device: thyristors, diacs, triacs, UJTs, programmable unijunction transistors (PUT), silicon bidirectional switch (SBS), opto-triacs etc.||BR100|
|S||Low-power switching transistor, bipolar or MOSFET, RthG > 15K/W||BS170|
|T||High-power control or switching device: thyristors, TRIACs, silicon bidirectional switch (SBS), etc.||BT138|
|U||High-power switching transistors, bipolar or MOSFET, RthG ≤ 15K/W||BU508, BUZ11|
|X||Frequency multiplier: varactor, step recovery diode|
|Y||High-power rectifying diode||BY228|
|Z||Avalanche, TVS, Zener diode||BZY91|
A 3-digit sequence number (or one letter then 2 digits, for industrial types) follows. Examples are:
|AC||Germanium small signal transistor||AC126|
|AF||Germanium RF transistor||AF117|
|BC||Silicon, small-signal transistor ("allround")||BC548B|
|BD||Silicon power transistor||BD139|
|BF||Silicon RF (high-frequency) BJT or FET||BF245|
|BS||Silicon switching transistor, bipolar or MOSFET)||BS170|
|BL||Silicon high-frequency, high-power (for transmitters)||BLW34|
|BU||Silicon high-voltage (for CRT horizontal deflection circuits)||BU508|
With early devices, the number indicated the case type. Suffixes may be used, such as a letter (e.g. "C" often means high hFE, such as in: BC549C). Other codes may follow to show gain (e.g. BC327-25) or voltage rating (e.g. BUK854-800A). A BC546 might only be marked "C546", thus possibly creating confusion with JIS abbreviated markings, because a transistor marked "C546" might also be a 2SC546.
- Short summary of semiconductor diode and transistor designations
BC549C / \ \ \___ variant (A,B,C for transistors implies low, medium or high gain) / \ \____ serial number (3 digits or letter and 2 digits) / \_____ device type: A=Germanium A=Signal diode B=Silicon C=LF low-power transistor C=GaAs D=Power transistor F=RF transistor (or FET) P=Photosensitive transistor T=Triac or thyristor Y=Rectifier diode Z=Zener diode
- Linear ICs begin with the letter "T", e.g. TAA570 limiter–amplifier and FM detector.
- Logic ICs begin with the letter "F".
- Mixed analog/digital ICs begin with the letter "U", e.g. UAA180 LED bargraph A/D and driver.
FCH171 // \ \__ serial number, gives the count and type of gates for example // \___ H=gate ("Combinatorial circuit") J=flip-flop K=monostable Q=RAM R=ROM etc. FC=DTL FD=MOS FJ=TTL
- JIS semiconductor designation
- Mullard–Philips tube designation
- RMA tube designation
- RETMA tube designation
- Russian tube designations
- "European Type Designation Code System for Electronic Components" (PDF) (16 ed.). Pro Electron, Brussels, Belgium. July 2010. Retrieved December 26, 2013.
- Datasheet for BC549, with A,B and C gain groupings
- datasheet for BUK854-800A (800 volt IGBT)
- Pro Electron
- European Type Designation Code System for Electronic Components (15 ed), Pro-Electron, Brussels, Belgium, 6/2008; with tube designation systems