Pro Electron

Pro Electron or 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).
Pro Electron was set up in 1966 in Brussels, Belgium. In 1983 it was merged with the European Electronic Component Manufacturers Association (EECA) and since then operates as an agency of the EECA.
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.
Designation system.
Examples of Pro Electron type designators are:
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:
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.
Electron tubes.
 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.
The serial number.
Following these two letters is a 3- or 4-digit serial number (or another letter then digits), assigned by Pro Electron. It is not always merely a sequence number; there is sometimes information conveyed in the number:
Suffixes and version specifiers.
Suffixes may be used, letters or perhaps blocks of digits delimited by "/" or "-" from the serial number, often without fixed meanings but some of the more common conventions are:
Examples of suffixes and manufacturers' extensions to the basic sequence number include:
Note: A BC546 might only be marked "C546" by some manufacturers, thus possibly creating confusion with JIS abbreviated markings, because a transistor marked "C546" might also be a 2SC546.
Short summary of the most common semiconductor diode and transistor designations:
 BC549C
 / |--- \___ variant (A,B,C for transistors implies low, medium or high gain)
 / | \____ serial number (at least 3 digits or letter and 2 digits)
 / device type:
 A=Ge A=Signal diode
 B=Si C=LF low-power transistor
 D=LF Power transistor
 F=RF transistor (or FET) 
 P=Photosensitive transistor etc.
 T=Triac or thyristor
 Y=Rectifier diode
 Z=Zener diode
Usage in the Eastern Bloc.
Poland, Hungary, Romania, and Cuba mostly used Pro Electron designations for discrete semiconductors just like Western Europe. Kombinat Mikroelektronik Erfurt (KME) in East Germany and Tesla (Czechoslovak company) used designations derived from the Pro Electron scheme. In particular, the first letter specifying the material differed while the second letter followed the table above (with the few exceptions for KME noted below).
Examples: - Germanium power transistor from KME; - optoisolator from KME; KD503 - Silicon power transistor from Tesla; - LED from Tesla.
Integrated circuits.
 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
Unfortunately the serial number does not specify the same type of gate in each family, e.g. while an FJH131 is a quadruple 2-input NAND gate (like the 7400), an FCH131 is a dual 4-input NAND gate.
External links.
[[Category:Electrical standards]]
[[Category:Electrical components]]
[[Category:Electronics lists]]