Siemens Aktiengesellschaft

Sarad Gesellschaft Fur Komplexe Leistungen Zur Sanierung Radiologisch

Roland Klinke

Bedrich J Hosticka

Hans-Joerg Pfleiderer

Thomas Streil

Radiation sensor arrangement for detecting the frequency of radiation

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.

Differential amplifier having externally controllable power consumption

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.

The differential amplifier has two n-channel or p-channel field effect transistors serving as controllable current sources which supply auxiliary currents upon appearance of an input signal which amplify the quiescent current. The inputs of the differential amplifier are connected to the gate terminals of the n-channel or p-channel field effect transistors via a level-converting circuit for converting the d.c. component of the input signal superimposed on a gate bias voltage to a lower or, respectively, higher output level. As a result of the control of the current sources proceeding from the amplifier input good driver qualities, a distortion-free signal transmission and a lower dissipation power are guaranteed.

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Dortmund, Germany

Roland Klinke