Differential amplifier circuit having improved control signal filtering

摘要

A circuit arrangement includes a differential amplifier, which supplies a balanced alternating voltage having a d.c. component which is filtered by means of a low-pass filter and is used for negative feedback. In order to avoid the use of a second filter capacitor, the voltages are supplied through a low-pass circuit to a second differential amplifier, which supplies an unbalanced d.c. control signal, which is supplied through a further low-pass filter having only one capacitor to the first differential amplifier.