Biasing

The quiescent current, and bias current (English bias current) called, is electrical current that flows continuously in a circuit, even if it is not active.

Halbleiterschaltungstechnik

In general, the quiescent current is reduced the efficiency of a circuit and is therefore usually undesirable.

In the semiconductor circuit technology is the quiescent current to adjust the operating point of importance. In semiconductor-based amplifiers, the quiescent current - depending on the circuit technology a significant portion of total consumption make up.

Furthermore, it is stated as an important parameter of integrated circuits and in the data sheets of the same.

The quiescent current is also available in tube amplifiers and must be set manually at the power tubes, otherwise the destruction of the tubes and / or the output transformer would result.

Alarm systems

For alarm systems, the quiescent current of the constant monitoring of a signal line is used. This type of monitoring is called the quiescent current principle. Open or short circuit of the bias current leads to the alarm.