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 a defined level of 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-bias and reverse-bias 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.