Exemplary multipath digital microphone described herein can comprise exemplary embodiments of adaptive ADC range multipath digital microphones, which allow low power to be achieved for amplifiers or gain stages, as well as for exemplary adaptive ADCs in exemplary multipath digital microphone arrangements described herein, while still providing a high DR digital microphone systems. Further non-limiting embodiments can comprise an exemplary glitch removal component configured to minimize audible artifacts associated with the change in the gain of the exemplary adaptive ADCs.

A motion sensor with sigma-delta analog-to-digital converter (ADC) having improved bias instability is presented herein. Differential outputs of a differential amplifier of the sigma-delta ADC are electrically coupled, via respective capacitances, to differential inputs of the differential amplifier. To minimize bias instability corresponding to flicker noise that has been injected into the differential inputs, the differential inputs are electrically coupled, via respective pairs of electronic switches, to feedback resistances based on a pair of switch control signals. In this regard, a first feedback resistance of the feedback resistances is electrically coupled to a first defined voltage, and a second feedback resistance of the feedback resistances is electrically coupled to a second defined reference voltage. The differential outputs are electrically coupled to differential inputs of a differential comparator of the sigma-delta ADC, and complementary outputs of the differential comparator comprise the pair of switch control signals.

This application relates to time-encoding modulators (301,700) having a self-oscillating modulator module configured to receive an input signal and output a pulse-width modulated signal (S.sub.PWM) where the pulse-width modulated signal is synchronised to a first clock signal (CLK.sub.1). A hysteretic comparator module (302) located in a feedforward path is configured to generate the time encoded signal (S.sub.PWM) at a first node (304) based on the input signal (S.sub.IN) and a feedback signal (S.sub.FB). A feedback path is coupled to the first node to provide the feedback signal, which is either applied to an input of the hysteretic comparator module via a loop filter (701) in the feedback path or applied to the feedforward path prior to a loop filter (701) upstream of the hysteretic comparator module (302). The hysteretic comparator module (302) is configured such that any change in state of the time encoded signal at the first node is synchronised to the first clock signal (CLK.sub.1).

Embodiments of the invention include an oversampling Analog to Digital Converter that uses uneven non-overlapping clock phases to reduce switched capacitor circuit power consumption. A return-to-zero sub phase of one of the clock phases may also be used for feedback reference capacitors. A delay lock loop may be combined with the non-overlapping clock phase generator to control accurate timing.

An Nth-order loop filter includes N integrators (where N is an integer value). The loop filter includes an initialization path coupled between an input to the loop filter and an input of at least one of the integrators. A control circuit is coupled to the Nth order filter. During a reset phase, the control circuit causes an initialization voltage to be sampled into a capacitance of the initialization path. During an initialization phase immediately following the reset phase, the control circuit causes the initialization voltage to be conveyed to the input(s) of the at least one integrator.

An apparatus for generating an output signal, may comprise a signal path having an analog signal path portion having an analog magnitude droop, a digital signal path portion having a digital magnitude droop, a digital-to-analog converter for converting the digital input signal into the analog signal, a first digital compensation filter that compensates for the analog magnitude droop, and a second digital compensation filter that compensates for the digital magnitude droop, such that the first digital compensation filter and the second digital compensation filter together compensate for magnitude droop of the signal path to ensure a substantially flat passband response of the signal path. An apparatus may include a delta-sigma modulator for quantization noise shaping of a digital signal, a digital-to-analog converter configured to generate an analog signal from the digital signal, and an amplifier configured to amplify the analog signal and powered from a charge pump, wherein the charge pump is configured to operate at a switching frequency approximately equal to a zero of a modulator noise transfer function of the delta-sigma modulator, such that the impact of charge pump noise on a total harmonic distortion noise of the apparatus is minimized.

This application relates to time-encoding modulators (301,700) having a self-oscillating modulator module configured to receive an input signal and output a pulse-width modulated signal (S.sub.PWM) where the pulse-width modulated signal is synchronised to a first clock signal (CLK.sub.1). A hysteretic comparator module (302) located in a feedforward path is configured to generate the time encoded signal (S.sub.PWM) at a first node (304) based on the input signal (S.sub.IN) and a feedback signal (S.sub.FB). A feedback path is coupled to the first node to provide the feedback signal, which is either applied to an input of the hysteretic comparator module via a loop filter (701) in the feedback path or applied to the feedforward path prior to a loop filter (202) upstream of the hysteretic comparator module (302). The hysteretic comparator module (302) is configured such that any change in state of the time encoded signal at the first node is synchronised to the first clock signal (CLK.sub.1).

Embodiments of the invention include an oversampling Analog to Digital Converter that uses uneven non-overlapping clock phases to reduce switched capacitor circuit power consumption. A return-to-zero sub phase of one of the clock phases may also be used for feedback reference capacitors. A delay lock loop may be combined with the non-overlapping clock phase generator to control accurate timing.

This application relates to time-encoding modulators (301,700) having a self-oscillating modulator module configured to receive an input signal and output a pulse-width modulated signal (S.sub.PWM) where the pulse-width modulated signal is synchronized to a first clock signal (CLK.sub.1). A hysteretic comparator module (302) located in a feedforward path is configured to generate the time encoded signal (S.sub.PWM) at a first node (304) based on the input signal (S.sub.IN) and a feedback signal (S.sub.FB). A feedback path is coupled to the first node to provide the feedback signal, which is either applied to an input of the hysteretic comparator module via a loop filter (701) in the feedback path or applied to the feedforward path prior to a loop filter (202) upstream of the hysteretic comparator module (302). The hysteretic comparator module (302) is configured such that any change in state of the time encoded signal at the first node is synchronized to the first clock signal (CLK.sub.1).

Embodiments of the invention include an oversampling Analog to Digital Converter that uses uneven non-overlapping clock phases to reduce switched capacitor circuit power consumption. A return-to-zero sub phase of one of the clock phases may also be used for feedback reference capacitors. A delay lock loop may be combined with the non-overlapping clock phase generator to control accurate timing.