Abstract: A circuit configuration for line adaptation and echo suppression includes a balance filter which is triggered by transmission signals and supplies output signals that are linked through a subtractor to a reception signal. An impedance adaptation filter is triggered by the reception signal and supplies an output signal that is linked through an adder to the transmission signal. An analog/digital converter converts analog reception signals into digital reception signals. A digital/analog converter converts digital transmission signals into analog transmission signals. The impedance adaptation filter processes digital signals and the balance filter processes analog signals.

Abstract: Direct voltage and alternating voltage signals are decoupled from a first and a second pair of leads. The pairs of leads each carry an alternating voltage signal and they are subject to a direct voltage between them. A capacitive connection of the leads with the inputs of a signal receiving device allows decoupling of the alternative voltage signal. For decoupling one pole of the direct voltage signal, diodes are provided that are connected to the leads of the respective pair of leads. The diodes are each connected via a respective current source transistor to one terminal for the pole of the direct voltage. The control terminals of the current source transistors are controlled by the center tap of a voltage divider connected between the diodes. The embodiment for direct voltage decoupling is readily integratable.

Abstract: A circuit configuration for converting a one-bit digital signal at a given sampling frequency into an analog signal, includes a multiplication device having one input receiving the digital signal, another input receiving a reference signal and an output. A delay device receives the digital signal, delays the digital signal by one period of a sampling frequency and has an output. A further multiplication device has one input connected to the output of the delay device, another input receiving the reference signal and an output. An adding device has inputs each being connected to the output of a respective one of the multiplication devices and an output at which the analog signal is available.