Abstract: An amplifier output stage that can be operated with low supply voltages and as a voltage amplification greater than one has two complementary transconductance amplifiers having asymmetrical characteristics of their output currents with reference to the input voltages. The amplifier output stage also has two power amplifiers following these transconductance amplifiers and whose outputs are connected to the output node of the amplifier output stage. The amplifier output stage also has a feedback network that is connected between the output node and a reference potential node and defines a feedback node that is connected to respectively one of the inputs of the transconductance amplifiers, whereas the other inputs of the transconductance amplifiers are connected to the input node of the amplifier output stage.

Abstract: A differential amplifier having externally controllable power consumption. The differential amplifier has an external circuit stage for signal-dependent setting of the power consumption. The circuit stage is composed of two field effect transistors connected parallel to one another that are arranged in series with a resistor of the output side via which the current source of the differential amplifier is set. The field effect transistors are driven by a level-converting circuit proceeding from the amplifier input, this level-converting circuit being equipped with a control circuit. The control circuit defines the operating points of the field effect transistors with and without applied input signal and thus controls the signal-dependent boosting of the amplifier current.

Abstract: A differential amplifier having externally controllable power consumption. Differential amplifiers have a "static-bias" stage for setting the quiescent currents that flow in parallel circuit branches. Two field effect transistors that are connected parallel to one another are in series with an output resistor of this stage, these field effect transistors being driven via a level-converting circuit given the appearance of an input signal to be amplified, such that a voltage boost occurs at the output resistor. This voltage boost leads to a current boost in the differential amplifier. Good driver properties, a distortion-free signal transmission and a low dissipated power are provided by this external control of the two field effect transistors that results from the amplifier inputs.