The present invention relates to a modulator for a digital amplifier and a device comprising such a modulator and a digital amplifier.

The modulator (100) comprises a pulse shaper (110) and a control unit (120) for controlling the pulse shaper (110) to convert an input signal into a bit stream (130) configured for a digital amplifier which encodes an amplitude value per clock of a carrier signal. The pulse shaper (110) can represent a respective amplitude value of the input signal with different bit patterns. The bit pattern respectively used by the pulse shaper is determined by the control unit (120) by means of a corresponding, associated control command. The modulator (100) is characterized in that in the control unit (120) an assignment (160) of the control commands to associated amplitude values resulting from amplification of the associated bit patterns with the digital amplifier (400) is stored or at least is provided in that the control unit (120) selects a control command per clock by means of the assignment (160) and the amplitude value of the input signal and drives the pulse shaper (110) accordingly.

A delta-sigma modulator (DSM) includes: a first summation circuit coupled to an input signal for subtracting an error feedback signal from the input signal; a tunable signal transfer function coupled to the first summation circuit for setting a desired pole in a frequency response of the DSM; a second summation circuit coupled to the tunable signal transfer function for adding a noise transfer function to an output of the tunable signal transfer function; and a quantizer coupled to the second summation circuit for quantizing an output of the second summation circuit to generate an output of the DSM. The output of the DSM is used as feedback to the first summation circuit as the error feedback signal, and the tunable signal transfer function is dynamically tuned to allow selecting and tuning a center frequency and a bandwidth of the DSM.

A sigma-delta converter including a sigma-delta modulator including at least one analog filter capable, for each cycle of a conversion phase, of receiving an internal analog signal originating from the analog input signal and of supplying an analog output signal, wherein: the contribution of the internal analog signal to the output value of the filter is smaller at a given cycle of the conversion phase than at a previous cycle, the contributions to the different cycles being governed by a first predetermined law which is a function of the rank of the cycle; and the duration of a given cycle of the conversion phase is shorter than the duration of a previous cycle, the durations of the different cycles being governed by a second predetermined law which is a function of the rank of the cycle in the conversion phase.

Provided are, among other things, systems, apparatuses, methods and techniques for converting a continuous-time, continuously variable signal into a sampled and quantized signal. One such apparatus includes an input line for accepting an input signal that is continuous in time and continuously variable, multiple processing branches coupled to the input line, and an adder coupled to outputs of the processing branches. Each of the processing branches includes a continuous-time quantization-noise-shaping circuit, a sampling/quantization circuit coupled to an output of the continuous-time quantization-noise-shaping circuit, a digital bandpass filter coupled to an output of the sampling/quantization circuit, and a line coupling an output of the digital-to-analog converter circuit back into the continuous-time quantization-noise-shaping circuit. A center frequency of the digital bandpass filter in each the processing branch corresponds to a minimum in a quantization noise transfer function for the continuous-time quantization-noise-shaping circuit in the same processing branch.

Provided are, among other things, systems, apparatuses, methods and techniques for converting a continuous-time, continuously variable signal into a sampled and quantized signal. One such apparatus includes an input line for accepting an input signal that is continuous in time and continuously variable, multiple processing branches coupled to the input line, and an adder coupled to outputs of the processing branches, with each of the processing branches including a bandpass noise-shaping circuit, a sampling/quantization circuit coupled to an output of the bandpass noise-shaping circuit, a digital bandpass filter coupled to an output of the sampling/quantization circuit, and a line coupling an output of the sampling/quantization converter circuit back into the bandpass noise-shaping circuit. A center frequency of the digital bandpass filter in each processing branch corresponds to a stopband region in a quantization noise transfer function for the bandpass noise-shaping circuit in the same processing branch.

Systems and methods for asynchronous data communication are disclosed. The system includes one or more peripheral devices, a processing device, and one or more communication channels. Each peripheral device includes a peripheral clock and a quantizer. The processing device is remotely located from each peripheral device and includes a processor clock that is asynchronous with at least one peripheral clock, an analog continuous time filter, and an analog-to-digital converter. The analog continuous time filter filters one or more quantized signals generated by the one or more peripheral devices to generate one or more filtered signals. The analog continuous time filter has a filter bandwidth corresponding to a signal bandwidth of one or more analog time varying signals represented by the one or more quantized signals. The analog-to-digital converter generates one or more converted signals by sampling the one or more filtered signals based on a processor clock signal.