Abstract: Implementations related to echo cancellation are depicted and described herein.

Abstract: The invention relates to a sigma-delta analogue/digital converter for an xDSL multi-standard input stage for converting an xDSL signal into a digital output signal, where the sigma-delta analogue/digital converter (1) has: an analogue loop filter (6) which filters an analogue difference signal between the xDSL signal to be converted and a feedback signal in order to produce a filter output signal; a quantizer which quantizes the filter output signal from the analogue loop filter (6) in order to produce the digital output signal; a first digital/analogue converter (16) which converts the digital output signal into the analogue feedback signal; where the analogue loop filter (6) has at least two resonator filter stages (6a, 6b) which respectively comprise a first integrator (6a-1; 6b-1) and a second integrator (6a-2; 6b-2) connected in series therewith, where the second integrator (6a-2; 6b-2) can be connected to the first integrator (6a-1, 6b-1) by means of a controllable feedback switch (6a-3, 6b-3) in order

Abstract: Implementations related to echo cancellation are depicted and described herein.

Abstract: The invention relates to a sigma-delta analogue/digital converter for an xDSL multi-standard input stage for converting an xDSL signal into a digital output signal, where the sigma-delta analogue/digital converter (1) has: an analogue loop filter (6) which filters an analogue difference signal between the xDSL signal to be converted and a feedback signal in order to produce a filter output signal; a quantizer which quantizes the filter output signal from the analogue loop filter (6) in order to produce the digital output signal; a first digital/analogue converter (16) which converts the digital output signal into the analogue feedback signal; where the analogue loop filter (6) has at least two resonator filter stages (6a, 6b) which respectively comprise a first integrator (6a-1; 6b-1) and a second integrator (6a-2; 6b-2) connected in series therewith, where the second integrator (6a-2; 6b-2) can be connected to the first integrator (6a-1, 6b-1) by means of a controllable feedback switch (6a-3, 6b-3) in order

Abstract: The invention relates to a line terminating device for a subscriber line which transmits and receives broadband signals via a single subscriber line, a broadband signal being composed of a broadband or narrowband audio-frequency data signal and a broadband higher-frequency data signal and the frequency bands of the voice signal and of the data signal essentially not overlapping. The line terminating device according to the invention has a digital frequency separating filter in the digital section of the line terminating device, which is arranged in the digital section of the line terminating device so that the audio-frequency voice signal is separated from the higher-frequency data signal. In particular, the line terminating device is suitable for separating an ISDN or POTS voice signal from an ADSL data signal.

Abstract: The invention relates to a linear SC circuit arrangement using integrated deep submicron technology, having at least one switched capacitor circuit which is connected to an input for inputting an input signal and which has at least one switchable capacitor and at least one first transistor, having a control circuit for directly actuating the first transistors, having an output stage which has second transistors and which is arranged downstream of the switched capacitor circuit, where the first transistors are in the form of thick oxide transistors and have a higher withstand voltage than the second transistors.

Abstract: In the line terminating device, which is provided for transmitting and receiving narrowband low-frequency voice signals and broadband data signals at a higher frequency, the analog reception path is subdivided into two separate analog paths (32, 33) for voice and data using a balance filter (49), which is used for data signal echo cancellation. In the transmission direction, the voice signal path and the data signal path are separated in the digital part by means of digital filters (43, 45). The invention is used for voice and data signal separation in xDSL methods, for example, ADSL.Lite.

Abstract: The invention relates to a circuit arrangement for forming the termination of an analogous subscriber line which comprises a first connection and a second connection for connecting a twin-wire analogous subscriber line. Said first connection is linked with said second connection via a series connection of a first capacitor, at least one first adjustable resistor and one second capacitor. According to the invention, a direct current source is linked with the first point of linkage of the first capacitor and the first adjustable resistor. Said direct current source impresses a current which serves to adjust an operating point for voice and data transmission via the analogous subscriber line. The first and the second capacitor block equisignals on the subscriber line so that no direct current can flow via the analogous subscriber line.

Abstract: The invention relates to an analog echo filter for a modem, to which an analog transmit signal is supplied. According to the invention, a passive analog input filter and an active analog filter, whose transfer function is adjustable, are provided. The transfer function of the active analog filter can preferably be switched between a first-order transfer function and a second-order transfer function.

Abstract: The invention relates to a linear SC circuit arrangement using integrated deep submicron technology, having at least one switched capacitor circuit which is connected to an input for inputting an input signal and which has at least one switchable capacitor and at least one first transistor, having a control circuit for directly actuating the first transistors, having an output stage which has second transistors and which is arranged downstream of the switched capacitor circuit, where the first transistors are in the form of thick oxide transistors and have a higher withstand voltage than the second transistors.

Abstract: A protective circuit for limiting a voltage at a pad of an integrated circuit includes a threshold selector connected between the pad and ground. The input voltage to the threshold selector is the pad voltage. The threshold detector includes a first transistor where load path is connected to the pad. The central terminal of the first transistor is maintained at a threshold voltage derived from the pad voltage. A second transistor has its control terminal connected to a second terminal of the load path of the first transistor. The load path of this second transistor is connected between the pad and ground.

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.