Circuit arrangement having a pre-amplifier connected to an opto-electric transducer

摘要

A circuit arrangement has a pre-amplifier that has its input connected to an opto-electric transducer and whose gain is controllable by a final control element formed by a field effect transistor. In order to achieve an especially great range of dynamics, the pre-amplifier contains the drain-source path of a field effect transistor that is connected in parallel to a resistor in a feedback branch. This field effect transistor is activated or inhibited by a regulator. In this way, the range of control of a controllable amplifier arrangement following the pre-amplifier is doubly utilized. The circuit arrangement can be advantageously used in optical transmission equipment of PCM technology.