The static current gain for a transistor is the ratio between the collector’s continuous current (Ic) and the base's continuous current (Ib) in a common emitter configuration as shown in figure.
Formula 1
Transistor gain:
b = Ic / Ib
Where:
b is the static current gain
Ic is the collector current in amperes (A) or submultiples
Ib is the base current in amperes (A) or submultiples
Application example:
A current change of 1 mA in the base of a transistor produces a collector current change of 50 mA. The transistor is in a common colletor configuration. Calculate the static gain of this transistor.
Data:
Ic = 50 mA
Ib = 1 mA
b = ?
Using formula 1:
b = 50/1 = 50
