The Pro Electron standard, the European Electronic Component Manufacturers Association part numbering scheme, begins with two letters: the first gives the semiconductor type (A for germanium, B for silicon, and C for materials like GaAs); the second letter denotes the intended use (A for diode, C for general-purpose transistor, etc.). A 3-digit sequence number (or one letter then 2 digits, for industrial types) follows. With early devices this indicated the case type. Suffixes may be used, with a letter (e.g. "C" often means high hFE, such as in: BC549C) or other codes may follow to show gain (e.g. BC327-25) or voltage rating (e.g. BUK854-800A). The more common prefixes are: COUNT 5
QSN1 What is the Pro Electron standard? ANS1 European Electronic Component Manufacturers Association part numbering scheme QSN2 How many letters does the part numbering scheme begin with? ANS2 two letters QSN3 What is the first letter in the part numbering scheme? ANS3 the semiconductor type QSN4 What is the second letter in the part numbering scheme? ANS4 the intended use QSN5 What follows the 2 letters in the part numbering scheme? ANS5 A 3-digit sequence number