Infineon Technologies Ag

Lantiq Deutschland Gmbh

Joerg Hauptmann

Alexander Kahl

David Schwingshackl

Andreas Wiesbauer

Dietmar Straeussnigg

Martin Clara

Richard Gaggl

Bernhard Zojer

Antonio Di Giandomenico

Paul Kunisch

Peter Pessl

Rudi Frenzel

Christian Schranz

Gerhard Paoli

Hans W Rudolf

Markus Terschluse

Frederic Pecourt

Manfred Preitnegger

Herbert Zoler

Aner Tenen

Gerald Krottendorfer

Dirk Schmuecking

Implementations related to echo cancellation are depicted and described herein.

Echo cancellation

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 () has: an analogue loop filter () 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 () in order to produce the digital output signal; a first digital/analogue converter () which converts the digital output signal into the analogue feedback signal; where the analogue loop filter () has at least two resonator filter stages () which respectively comprise a first integrator (--) and a second integrator (--) connected in series therewith, where the second integrator (--) can be connected to the first integrator (--) by means of a controllable feedback switch (--) in order to close a local feedback loop, where the integrator outputs can respectively be connected by means of a controllable switch () to a signal input of an adder () which adds the output signals from the integrators in order to produce the filter output signal.

Sigma-delta analog-digital converter for an xDSL multistandard input stage

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.

Line terminator unit for a subscriber line

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.

SC circuit arrangement

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 () for voice and data using a balance filter (), 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 (). The invention is used for voice and data signal separation in xDSL methods, for example, ADSL.Lite.

Line termination device for a telephone subscriber line

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.

Circuit arrangement for forming the termination of an analogous subscriber line

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.

Analogue echo filter

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.

Protective circuit

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Wernberg, Austria

Joerg Hauptmann