Abstract: Analogue filter for filtering out a high-frequency switching noise in a pulse-width-modulated transmit signal, which is fed into a line by a line driver by means of a transformer, wherein at least one capacitor is connected in parallel to a secondary winding of the transformer and, together with a stray inductivity of the transformer, forms the analogue filter.

Abstract: A signal is modulated by generating a pulse-width modulation signal and applying the pulse-width modulation signal to an input of a switched-mode amplifier. An output of the amplifier is coupled to a filter operable to impart either differential mode oscillations or common mode oscillations at the amplifier output based on the duty cycle of the pulse-width modulation signal. The duty cycle of the pulse-width modulation signal is varied to impart amplitude modulations at the amplifier output.

Abstract: One embodiment relates to a power amplifier that includes a switched mode power amplification stage. The power amplification stage has an output configured to provide an amplified output voltage as a function of a drive signal, where the drive signal fluctuates during a first time and is inactive during a second time. The power amplifier also includes impedance compensation circuitry coupled to the output of the power amplification stage. The impedance compensation circuitry can selectively alter an output impedance of the power amplification stage as a function of a control signal that is continuously de-asserted during the first time and continuously asserted during the second time. Other embodiments are also disclosed.

Abstract: One embodiment relates to a power amplifier that includes a switched mode power amplification stage. The power amplification stage has an output configured to provide an amplified output voltage as a function of a drive signal, where the drive signal fluctuates during a first time and is inactive during a second time. The power amplifier also includes impedance compensation circuitry coupled to the output of the power amplification stage. The impedance compensation circuitry can selectively alter an output impedance of the power amplification stage as a function of a control signal that is continuously de-asserted during the first time and continuously asserted during the second time. Other embodiments are also disclosed.

Abstract: A signal is modulated by generating a pulse-width modulation signal and applying the pulse-width modulation signal to an input of a switched-mode amplifier. An output of the amplifier is coupled to a filter operable to impart either differential mode oscillations or common mode oscillations at the amplifier output based on the duty cycle of the pulse-width modulation signal. The duty cycle of the pulse-width modulation signal is varied to impart amplitude modulations at the amplifier output.

Abstract: A class D power output stage for switching a supply voltage comprises a limiting transistor with a controllable path and a control terminal, a complementary limiting transistor with a controllable path and a control terminal, a switching transistor with a controllable path and a control terminal, and a complementary switching transistor with a controllable path and a control terminal. A switched output signal between the controllable paths of the limiting and complementary limiting transistors can be taped off, the controllable paths of the limiting and the complementary limiting transistors are connected together and are connected to a first and a second supply terminal via the controllable paths of the switching and complementary switching transistors, and the switching and the complementary switching transistors have a lower electrical strength than the limiting and complementary limiting transistors.

Abstract: Analogue filter for filtering out a high-frequency switching noise in a pulse-width-modulated transmit signal, which is fed into a line by a line driver by means of a transformer, wherein at least one capacitor is connected in parallel to a secondary winding of the transformer and, together with a stray inductivity of the transformer, forms the analogue filter.

Abstract: A class D power output stage for switching a supply voltage comprises a limiting transistor with a controllable path and a control terminal, a complementary limiting transistor with a controllable path and a control terminal, a switching transistor with a controllable path and a control terminal, and a complementary switching transistor with a controllable path and a control terminal. A switched output signal between the controllable paths of the limiting and complementary limiting transistors can be taped off, the controllable paths of the limiting and the complementary limiting transistors are connected together and are connected to a first and a second supply terminal via the controllable paths of the switching and complementary switching transistors, and the switching and the complementary switching transistors have a lower electrical strength than the limiting and complementary limiting transistors.

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

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