Abstract: An electric circuit for amplifying an xDSL signal comprises an operational amplifier and a signal monitoring circuit. The operational amplifier is configured to amplify the xDSL signal, is powered by a variable voltage supply and has a gain which is adjustable by an operating mode control signal. The signal monitoring circuit is activated by the operating mode control signal and is configured, when activated by the operating mode control signal, to generate a control signal to adjust the voltage of the variable voltage supply in order to adjust the maximal signal swing of the output signal of said operational amplifier. The control signal is generated by comparing the amplitude of the xDSL signal applied to the electric circuit with an amplitude threshold value.

Abstract: An electric circuit for amplifying an xDSL signal comprises an operational amplifier and a signal monitoring circuit. The operational amplifier is configured to amplify the xDSL signal, is powered by a variable voltage supply and has a gain which is adjustable by an operating mode control signal. The signal monitoring circuit is activated by the operating mode control signal and is configured, when activated by the operating mode control signal, to generate a control signal to adjust the voltage of the variable voltage supply in order to adjust the maximal signal swing of the output signal of said operational amplifier. The control signal is generated by comparing the amplitude of the xDSL signal applied to the electric circuit with an amplitude threshold value.

Abstract: at least one self oscillating loop circuit which oscillates with a switching frequency (fs), wherein the self oscillating loop circuit (18, 19, 20) comprises an output driver (19) which is switched with said switching frequency and a loop filter (20) which feeds back an amplified loop signal output by said driver (19) to an input of said self oscillating loop and a trimming circuit (21) for trimming the switching frequency (fs) of said self oscillating loop circuit.

Abstract: An electric circuit for amplifying an xDSL signal comprises an operational amplifier and a signal monitoring circuit. The operational amplifier is configured to amplify the xDSL signal, is powered by a variable voltage supply and has a gain which is adjustable by an operating mode control signal. The signal monitoring circuit is activated by the operating mode control signal and is configured, when activated by the operating mode control signal, to generate a control signal to adjust the voltage of the variable voltage supply in order to adjust the maximal signal swing of the output signal of said operational amplifier. The control signal is generated by comparing the amplitude of the xDSL signal applied to the electric circuit with an amplitude threshold value.

Abstract: An electric circuit for amplifying an xDSL signal comprises an operational amplifier and a signal monitoring circuit. The operational amplifier is configured to amplify the xDSL signal, is powered by a variable voltage supply and has a gain which is adjustable by an operating mode control signal. The signal monitoring circuit is activated by the operating mode control signal and is configured, when activated by the operating mode control signal, to generate a control signal to adjust the voltage of the variable voltage supply in order to adjust the maximal signal swing of the output signal of said operational amplifier. The control signal is generated by comparing the amplitude of the xDSL signal applied to the electric circuit with an amplitude threshold value.

Abstract: Implementations related to multi-standard digital subscriber line analog-to-digital data conversion are described.

Abstract: Implementations related to multi-standard digital subscriber line analog-to-digital data conversion are described.

Abstract: The present invention relates to a circuit for electronically generating a call impedance in telephone terminals, comprising a call alternating voltage that may be tapped between a first and a second input terminal. The inventive circuit has a regulating device with a programmable digital filter for regulating impedance, wherein the transmission function of the regulating device can be adjusted by programming the filter coefficients of the digital filter. The inventive regulating device makes it possible to adapt the call impedance to different country-specific requirements. To this end, the regulating device has a programmable digital filter that may be embodied as a digital signal processor. In an especially preferred embodiment, the digital filter is implemented in the form of a program in the digital signal processor.

Abstract: Tone signal detection circuit for a receiving circuit for detecting at least one tone signal of predetermined tone signal frequency (fE) which is contained in a received analog input signal, comprising a reference signal generator (41) for generating an analog converter reference signal which consists of a reference DC (VrefDC) and a periodic reference AC (VrefAC) having a variable fundamental frequency (fG), which is superimposed on the reference DC, an analog/digital converter (11) for converting the analog input signal into a digital data stream in dependence on the analog converter reference signal (Vref); and comprising a digital control circuit (20) which adjusts the variable fundamental frequency (fG) of the reference signal (Vref) generated by the reference signal generator (42) in accordance with the predetermined tone signal frequencies (fG) of the tone signals to be detected and evaluates the digital data stream output by the digital analog/digital converter (11) for detecting a data pattern corres

Abstract: An electric circuit for amplifying an xDSL signal comprises an operational amplifier and a signal monitoring circuit. The operational amplifier is configured to amplify the xDSL signal, is powered by a variable voltage supply and has a gain which is adjustable by an operating mode control signal. The signal monitoring circuit is activated by the operating mode control signal and is configured, when activated by the operating mode control signal, to generate a control signal to adjust the voltage of the variable voltage supply in order to adjust the maximal signal swing of the output signal of said operational amplifier. The control signal is generated by comparing the amplitude of the xDSL signal applied to the electric circuit with an amplitude threshold value.

Abstract: at least one self oscillating loop circuit which oscillates with a switching frequency (fs), wherein the self oscillating loop circuit (18, 19, 20) comprises an output driver (19) which is switched with said switching frequency and a loop filter (20) which feeds back an amplified loop signal output by said driver (19) to an input of said self oscillating loop and a trimming circuit (21) for trimming the switching frequency (fs) of said self oscillating loop circuit.

Abstract: The invention creates a method and a device for digitally transmitting analog signals, in which oversampling is performed in analog/digital and digital/analog converters. In this arrangement, a digital/analog conversion is performed which, in particular, is suitable for VDSL systems. A transmitted digital transmission signal (110) is supplied to a mixing unit (201) and in the mixing unit (201), a receive noise signal (211) applied to a receive noise source terminal (209) is superimposed on the digital transmission signal (110). An interpolation filter unit (203), in combination with a subsequent noise shaping device (205), provides an increase in the frequency bandwidth, resulting in suitable oversampling.

Abstract: The invention creates a method and a device for digitally transmitting analog signals, in which oversampling is performed in analog/digital and digital/analog converters. In this arrangement, a digital/analog conversion is performed which, in particular, is suitable for VDSL systems. A transmitted digital transmission signal (110) is supplied to a mixing unit (201) and in the mixing unit (201), a receive noise signal (211) applied to a receive noise source terminal (209) is superimposed on the digital transmission signal (110). An interpolation filter unit (203), in combination with a subsequent noise shaping device (205), provides an increase in the frequency bandwidth, resulting in suitable oversampling.

Abstract: A digital-to-analog converter arrangement able to process input signals with different signal bandwidth is provided. The arrangement comprises a first input terminal for receiving a first digital input signal, a second input terminal for receiving a second digital input signal and switching means being coupled to the first and second input terminals and being adapted to select between the first and second digital input signals so as to output an intermediate digital signal corresponding to the selected one of the first and second digital input signals. The intermediate digital signal is received by an array of unary digital-to-analog converting elements, each unary digital-to-analog converting element being adapted so that, as an analog output signal, a sum signal of output signals of the unary digital-to-analog converting elements is output.

Abstract: A digital-to-analog converter arrangement able to process input signals with different signal bandwidth is provided. The arrangement comprises a first input terminal for receiving a first digital input signal, a second input terminal for receiving a second digital input signal and switching means being coupled to the first and second input terminals and being adapted to select between the first and second digital input signals so as to output an intermediate digital signal corresponding to the selected one of the first and second digital input signals. The intermediate digital signal is received by an array of unary digital-to-analog converting elements, each unary digital-to-analog converting element being adapted so that, as an analog output signal, a sum signal of output signals of the unary digital-to-analog converting elements is output.

Abstract: A circuit arrangement for signaling in telecommunications networks has a first connection and a second connection for a first and a second conductor, respectively, in a transmission line. The first connection is connected to the first input of a rectifier, and the second connection is connected to the second input of said rectifier. The positive output and the negative output of the rectifier are connected to one another via a variable resistance. A third connection for a third conductor in the transmission line can be connected via the series circuit formed by a switch and a first diode to the positive output of the rectifier, and via the series circuit formed by the switch and a second diode to the negative output of the rectifier.

Abstract: A sigma-delta analog-to-digital converter includes an integrator and a dither signal generator for generating a digital dither signal, and a plurality of comparators for converting an analog signal received from the integrator into an output digital value. A digital logic unit is in data communication with the digital dither signal and the comparators. The digital logic unit is configured to change the output digital value on the basis of the digital dither signal.

Abstract: The invention relates to a circuit configuration for two-wire/four-wire conversion. The circuit configuration has a receiver which is coupled on an input side to a digital two-wire reception path via which its receives a digital signal. A signal-processor is connected downstream of the receiver and emits a first and second signal. An echo-canceling device receives the first signal and emits a third signal. A digital-to-analog converter is provided which receives the second signal and emits a fourth signal. A hybrid circuit is coupled to an analog four-wire transmission-reception path, receives the fourth signal, and emits a fifth signal. An analog-to-digital converter receives the fifth signal and emits a sixth signal. A transmitter receives the sixth signal and is coupled on an output side to a digital two-wire transmission path and emits a digital transmitted signal to the latter. In the invention, the digital-to-analog converter has a sigma-delta modulator.

Abstract: A sigma-delta analog-to-digital converter includes an integrator and a dither signal generator for generating a digital dither signal, and a plurality of comparators for converting an analog signal received from the integrator into an output digital value. A digital logic unit is in data communication with the digital dither signal and the comparators. The digital logic unit is configured to change the output digital value on the basis of the digital dither signal.

Abstract: The invention relates to a circuit configuration for quantization of digital signals and for filtering quantization noise. Said circuit configuration comprises a multitude of digital control loops connected in series and having quantizers. The digital signals having a word length of m-bits are fed to a first control loop in the series. The quantization error signal of each quantizer is filtered and fed back to the corresponding digital control loop. It is then fed to a downstream digital control loop. The quantized output signal of the first digital control loop is adapted to a third word length of u-bits which is smaller than the first word length. Except for the quantized output signal of the first digital control loop, the quantized output signals of the digital control loops of the series are respectively filtered by a digital filter.