Infineon Technologies Ag

Lantiq Deutschland Gmbh

Maxlinear, Inc.

Christian Fleischhacker

Martin Clara

Andreas Wiesbauer

Michael Staber

Hubert Weinberger

Rainer Strobel

Thomas Ferianz

Daniel Gruber

Boaz Porat

Peter Pessl

Thomas Pötscher

Dario Giotta

Wolfgang Klatzer

Rüdiger Koban

Antonio Digiandomenico

Francesco Labate

Tina Thelesklav

Hubert Weingerger

Günter Koder

A line driver circuit has first and second differential input terminals and first and second differential output terminals, and is configured to interface with first and second termination impedances coupled between the first and second differential output terminals, respectively, and first and second transmit chain output terminals, respectively. The line driver circuit includes an amplifier circuit having first and second input terminals coupled to the first and second differential input terminals of the line driver circuit, respectively, and first and second output terminals coupled to the first and second differential output terminals of the line driver circuit, respectively, and an impedance switching circuit coupled between the first and second output terminals of the amplifier circuit. The impedance switching circuit switches between a first switching mode and a second switching mode, wherein in the first switching mode a first switching configuration is established resulting in a first output impedance.

Time division duplexing receiver with constant impedance for a broadband line terminal with asynchronous transmission

Embodiments related to echo compensation have been described and depicted.

Echo cancellation

A differential gain stage includes a plurality of programmable passive circuit component arrays operable to set a gain of the gain stage. The gain stage also includes an active switch gate control circuit and a passive switch gate control circuit. The active switch gate control circuit controls a gate voltage applied to transistor switch components of each programmable passive circuit component array as a function of the level of common mode disturbance input to the differential gain stage for common mode frequencies below a particular frequency threshold. The passive switch gate control circuit controls the gate voltage applied to the transistor switch components as a function of the level of common mode disturbance for common mode frequencies above the frequency threshold. The differential gain stage can for part of a receiver such as an xDSL receiver.

Common-mode robust high-linearity analog switch

Bridge circuit for echo suppression for a reception signal of a communication device connected to a transmission line, to which can be supplied a reception signal received via the transmission line and a transmission signal to be transmitted by the communication device via the transmission line. The bridge circuit is designed such that on balancing the bridge circuit, the reception signal there can be tapped echo-compensated with a transmission signal part generated by the transmission signal being suppressed. To balance the bridge circuit a variable simulation device is provided to simulate at least one circuit section of at least one bridge branch and connect with the at least one bridge branch. By such an arrangement, the signal level in the simulation device may be reduced so far that this can be designed as an integrated circuit and to be programmable.

Bridge circuit to suppress echoes in communication devices

An xDSL data transfer system for data transfer includes at least one xDSL user modem connected via a data transfer medium to a corresponding xDSL modem within a central office, in which the xDSL user modem generates a pulse length modulated wake-up signal for switching the corresponding xDSL modem within the central office from a sleep mode to an operation mode.

System and method for establishing an xdsl data transfer link

An adjustable filter, particularly for use as an antialiasing filter in digital telecommunications networks, includes adjustable capacitors which determine frequency response for the purpose of accurate alignment with a particular cut-off frequency. The active filter includes, in line with the invention, a control device with a measuring device for ascertaining the actual cut-off frequency of the filter. On the basis of the ascertained actual cut-off frequency of the filter and the information about the nominal cut-off frequency which is to be set, an adjustment parameter for the adjustable capacitor is selected from a memory arrangement. This adjustment parameter is used to adjust the adjustable capacitor such that the desired nominal cut-off frequency is obtained and, at the same time, the alignment is performed to achieve the nominal cut-off frequency with sufficient accuracy.

Method and apparatus for adjusting an active filter

The invention relates to a line driver arrangement for driving signals via at least one subscriber line, provided with:

Line driver

Programmable echo cancellation filter for echo signal cancellation for a transceiver having a signal input () for receiving the transmission signal emitted by the transceiver (), an input resistor () connected to the signal input (), an operational amplifier (), whose signal input () is connected to the input resistor () and whose signal output () is connected to an output resistor (), a first programmable resistor circuit (), which is provided between the signal output () of the operational amplifier () and the signal input () of the operational amplifier, a second programmable resistor circuit (), which is provided between the output resistor () and a signal output () of the echo cancellation filter (), a third programmable resistor circuit () which is provided between the first programmable resistor circuit () and the signal output () of the echo cancellation filter (), the programmable resistor circuits () each having a plurality of resistors () which are terminated in parallel and are connected to a first terminal () of an associated controllable switch (), the controllable switches () having a second terminal () connected to a virtual reference voltage terminal with a very low voltage swing.

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Pischeldorf, Austria

Christian Fleischhacker