Pro Electron

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).

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:

Package NPN PNP
TO-18 BC10x BC17x
Lockfit BC14x BC15x
TO-92 BC54x BC55x

... 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.

Differences between Pro Electron and earlier valve-naming conventions

Frequently used first letters in European active devices

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

As listed above, the first letter gives the semiconductor type; the second letter denotes the intended use:

2nd letter Usage Example
ALow-power/small-signal diode AA119, BA121
BVaricap diode BB105G
CSmall signal transistor, RthG > 15K/W BC546C
DHigh-power, low-frequency power transistor, RthG  15K/W BD139
ETunnel (Esaki-)diode AE100
FLow-power, RF (high-frequency) bipolar or FET, RthG > 15K/W BF245
GHybrid device BGY32, BGY585
HHall-effect sensor/diode
LHigh-frequency, high-power transistor (for transmitters), RthG  15K/W BLW34
MRing modulator-type frequency mixer
NOpto-isolator CNY17
PRadiation detector (photodiode, phototransistor) BPW34
QRadiation generator (LED) CQY99
RLow-power control or switching device: thyristors, diacs, triacs, UJTs, programmable unijunction transistors (PUT), silicon bidirectional switch (SBS), opto-triacs etc. BR100
SLow-power switching transistor, bipolar or MOSFET, RthG > 15K/W BS170
THigh-power control or switching device: thyristors, TRIACs, silicon bidirectional switch (SBS), etc. BT138
UHigh-power switching transistors, bipolar or MOSFET, RthG  15K/W BU508, BUZ11
VAntenna
WSurface-acoustic-wave device
XFrequency multiplier: varactor, step recovery diode
YHigh-power rectifying diode BY228
ZAvalanche, TVS, Zener diode BZY91

A 3-digit sequence number (or one letter then 2 digits, for industrial types) follows.[1] Examples are:

Prefix class Usage Example
ACGermanium small signal transistor AC126
AFGermanium RF transistor AF117
BCSilicon, small-signal transistor ("allround") BC548B
BDSilicon power transistor BD139
BFSilicon RF (high-frequency) BJT or FET BF245
BSSilicon switching transistor, bipolar or MOSFET) BS170
BLSilicon high-frequency, high-power (for transmitters) BLW34
BUSilicon 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[2]). Other codes may follow to show gain (e.g. BC327-25) or voltage rating (e.g. BUK854-800A[3]). 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.

    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

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.[1]

See also

References

External links