Abstract: A line driver circuit having an amplifier circuit having a differential output, the differential output including a first output terminal and a second output terminal and an impedance switching circuit coupled between the first output terminal and the second output terminal of the amplifier circuit, wherein the impedance switching circuit is configured to reduce or maintain impedance across the first output terminal and the second output terminal of the amplifier circuit.

Abstract: 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.

Abstract: 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.

Abstract: Embodiments related to echo compensation have been described and depicted.

Abstract: 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.

Abstract: 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.

Abstract: Embodiments related to echo compensation have been described and depicted.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: The invention relates to a line driver arrangement for driving signals via at least one subscriber line, provided with: an input for injecting an input signal and having an output at which a signal which is to be driven via the subscriber line can be tapped off, a digital amplifier which produces a pulse-width-modulated signal on the output side from the input signal or from a signal derived from it, an analog amplifier, which produces an analog signal on the output side from the input signal or from a signal derived from it, with the outputs of the amplifiers being coupled such that the signal to be driven results from superimposition of the analog signal and the digital signal, with the gain of the analog amplifier being matched to the gain of the digital amplifier such that scatter and/or overshoot on the digital signal are at least reduced after the superimposition.

Abstract: Programmable echo cancellation filter for echo signal cancellation for a transceiver having a signal input (13) for receiving the transmission signal emitted by the transceiver (1), an input resistor (36) connected to the signal input (13), an operational amplifier (39), whose signal input (38) is connected to the input resistor (36) and whose signal output (41) is connected to an output resistor (43), a first programmable resistor circuit (48), which is provided between the signal output (41) of the operational amplifier (39) and the signal input (38) of the operational amplifier, a second programmable resistor circuit (51), which is provided between the output resistor (43) and a signal output (15) of the echo cancellation filter (14), a third programmable resistor circuit (55) which is provided between the first programmable resistor circuit (48) and the signal output (15) of the echo cancellation filter (14), the programmable resistor circuits (48, 51, 55) each having a plurality of resistors (65) which a

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

Abstract: 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.

Abstract: 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.

Abstract: Digital/analog converter with programmable gain for converting a digital input signal (Dn) into an analog output signal, the digital/analog converter (1) having: a signal input (2) for applying the digital input signal (Dn) a reference current source (7) for generating a reference current (Iref&phgr;), the current intensity of the reference current output by the reference current source (7) being adjustable via a setting terminal (4) of the digital/analog converter (1) current mirror circuits which mirror the generated reference current (Iref) with an associated current mirror ratio to form mirror currents a controllable switching device (57), which switches through the mirror currents output by the current mirror circuits, in a manner dependent on the digital input signal (Dn) present at the signal input (2), to a summation current node (62) for generating a summation current (Isum) and a current/voltage converter (17) for converting the generated summation current (Isum) into a corresponding voltage (U

Abstract: Programmable echo cancellation filter for echo signal cancellation for a transceiver having a signal input (13) for receiving the transmission signal emitted by the transceiver (1), an input resistor (36) connected to the signal input (13), an operational amplifier (39), whose signal input (38) is connected to the input resistor (36) and whose signal output (41) is connected to an output resistor (43), a first programmable resistor circuit (48), which is provided between the signal output (41) of the operational amplifier (39) and the signal input (38) of the operational amplifier, a second programmable resistor circuit (51), which is provided between the output resistor (43) and a signal output (15) of the echo cancellation filter (14), a third programmable resistor circuit (55), which is provided between the first programmable resistor circuit (48) and the signal output (15) of the echo cancellation filter (14), the programmable resistor circuits (48, 51, 55) each having a plurality of resistors (65) which

Abstract: Digital/analog converter with programmable gain for converting a digital input signal (Dn) into an analog output signal, the digital/analog converter (1) having: