A radio frequency system. In some embodiments, the system includes a one-bit receiver, and the one-bit receiver includes a digital pseudo random noise generator, a one-bit digital to analog converter, a power combiner, a one-bit analog to digital converter, and a digital subtraction circuit. The digital pseudo random noise generator produces a signal added to the received signal before analog to digital conversion. After analog to digital conversion, a delayed version of the dither is subtracted from the digital signal.

A PDM (pulse density modulation) signal energy detection circuit includes a digital-to-analog converter circuit for receiving a PDM digital input signal and producing an analog output signal based on the PDM digital input signal. The PDM signal energy detection circuit also includes a comparator circuit for receiving the analog output signal from the digital-to-analog converter circuit and producing a pulsed signal when a magnitude of the analog output signal exceeds a pre-set threshold. The PDM signal energy detection circuit also has a counter circuit for receiving the pulsed signal from the comparator circuit and producing an energy detection signal when a number of consecutive pulsed signals exceed a pre-set count.

Methods and apparatus for shaping and filtering quantization errors conjointly in space and time to produce a higher-precision output in a spatially and temporally oversampled array. A space-time error-shaping array system has an array of sensors, each sensor producing a temporal signal comprising quantized waveforms. A multi-input multiple-output (MIMO) discrete-time filter structure with multiple inputs, each coupled to a sensor of the array of sensors, shapes quantization errors of the array of sensors on the basis of temporal aspects of the quantized waveforms conjointly with spatial aspects of the quantized waveforms.

The disclosure relates to a microphone assembly including a multibit analog-to-digital converter configured to generate N-bit samples representative of a microphone signal. The microphone assembly also includes a first digital-to-digital converter configured to generate a corresponding M-bit digital signal based on N-bit digital samples, wherein N and M are positive integers and N>M. The microphone assembly may include a data interface configured to repeatedly receive samples of the M-bit digital signal and write bits of the M-bit digital signal to a data frame.

Systems and methods according to one or more embodiments are provided for improving noise performance in a delta sigma modulator comprising an adder, quantizer and nth order filter. The adder is operable to receive an input signal and a feedback signal, and output a modified input signal. The quantizer is operable to receive the modified input signal and output a quantized output signal, the quantized output signal having a corresponding quantization error. The nth order filter is operable to receive a quantization error value and generate the feedback signal, the nth order filter comprising a first memory element having a first error value, a second memory element having a second error value, and a gravity component operable to converge the first error value and the second error value when the input signal is approximately zero.

The disclosure relates to a microphone assembly including a multibit analog-to-digital converter configured to generate N-bit samples representative of a microphone signal. The microphone assembly also includes a first digital-to-digital converter configured to generate a corresponding M-bit digital signal based on N-bit digital samples, wherein N and M are positive integers and N>M. The microphone assembly may include a data interface configured to repeatedly receive samples of the M-bit digital signal and write bits of the M-bit digital signal to a data frame.

Techniques for generating signals with arbitrary noise shaping are discussed. One example apparatus configured to be employed within a transmitter can comprise a noise shaper configured to: receive an input signal x.sub.q; and apply noise shaping to the input signal x.sub.q to generate a noise shaped output signal y.sub.q, wherein an in-band noise of the noise shaped output signal y.sub.q is below an in-band noise threshold of a spectral mask associated with the noise shaper, wherein an out-of-band noise of the noise shaped output signal y.sub.q is below an out-of-band noise threshold of the spectral mask, and wherein a noise of the output signal y.sub.q in each of a plurality of bandpass regions is below an associated noise threshold for that bandpass region of the spectral mask.

The disclosure relates to a microphone assembly including a multibit analog-to-digital converter configured to generate N-bit samples representative of a microphone signal. The microphone assembly also includes a first digital-to-digital converter configured to generate a corresponding M-bit digital signal based on N-bit digital samples, wherein N and M are positive integers and N>M. The microphone assembly may include a data interface configured to repeatedly receive samples of the M-bit digital signal and write bits of the M-bit digital signal to a data frame.

The disclosure relates to a microphone assembly comprising a multibit analog-to-digital converter configured to receive, sample, and quantize a microphone signal to generate N-bit digital microphone samples representative of the microphone signal at a first sampling frequency. The microphone assembly also comprises a first digital-to-digital converter configured to receive, quantize, and noise-shape the N-bit digital microphone samples to generate a corresponding M-bit Pulse Density Modulated (PDM) signal, wherein N and M are positive integers, and N>M. The microphone assembly may comprise a SoundWire compliant data interface configured to repeatedly receive samples of the M-bit PDM signal and write bits of the M-bit PDM signal to a SoundWire data frame.

A sigma-delta modulator including at least first and second sub-modulators, each including an analog integration circuit, the analog integration circuit of the first sub-modulator having an output node connected to an input node of the analog integration circuit of the second sub-modulator, the modulator further comprising a coupling capacitor having a first electrode connected to an output node of the analog integration circuit of the second sub-modulator, and a comparator having its input coupled to the first electrode of the coupling capacitor by a first switch and to a second electrode of the coupling capacitor by a second switch.