Safe Operating Area

Transistor refers to the range of input and output voltages and currents within which the device can operate for its specified service life with defined reliability, without causing failure or degradation. Normally, this is the range of specified rated input and output values. A transistor has a safe operating area for both forward-biased and reverse-biased conditions. When a transistor is used in high-power amplifiers or circuits with inductive loads, degradation or destruction may occur even within the safe operating area of its rated values, so caution is required.