The technology described in this document can be embodied in an apparatus that includes an amplifier that includes a first Zeta converter connected to a power supply and a load. The amplifier also includes a second Zeta converter connected to the power supply and the load. The second Zeta converter is driven by a complementary duty cycle relative to the first Zeta converter. The amplifier also includes a controller to provide an audio signal to the first Zeta converter and the second Zeta converter for delivery to the load.

Disclosed are a hybrid mode based audio processing method and an apparatus therefor. A hybrid mode based audio processing apparatus according to an exemplary embodiment of the present disclosure includes a signal converting unit which converts a digital signal of an input sound source into an analog signal; a mode controller which analyzes the input sound source, sets an amplification mode according to the analysis result, and generates an amplification control signal to control the amplification mode; an amplifying unit which amplifies the analog signal in the amplification mode set based on the amplification control signal; and an audio output unit which outputs an audio corresponding to the amplified analog signal.

A modular vehicle sound system that can be upgraded or reconfigured by changing a plug-in module. In the advanced-capability embodiments the invention combines the functions of a vehicle data bus interface, a digital signal processor, and an amplifier. In the advanced-capability embodiments the invention provides a wireless interface with a separate digital device that can be used to control the inventive amplifier.

A digital signal generator apparatus and method is described. The digital signal generator includes a counter, an integrator and a comparator. The counter counts up or down from an initial counter value dependent on a counter control input. The comparator has a first input coupled to the counter output, a threshold input and a comparator output coupled to the counter control input. The integrator has an input coupled to the counter output and an output coupled to the digital signal generator output. The digital signal generator determines the count direction after the initial direction dependent on the comparison between a threshold value applied to the threshold input and the counter output value. The digital signal generator may implement the generation of a waveform having an approximation to a raised cosine function. The generated waveform may be used for audio artefact reduction in an audio amplifier during mute or unmute operations or during power up power down operations.

A digital signal generator apparatus and method is described. The digital signal generator includes a counter, an integrator and a comparator. The counter counts up or down from an initial counter value dependent on a counter control input. The comparator has a first input coupled to the counter output, a threshold input and a comparator output coupled to the counter control input. The integrator has an input coupled to the counter output and an output coupled to the digital signal generator output. The digital signal generator determines the count direction after the initial direction dependent on the comparison between a threshold value applied to the threshold input and the counter output value. The digital signal generator may implement the generation of a waveform having an approximation to a raised cosine function. The generated waveform may be used for audio artefact reduction in an audio amplifier during mute or unmute operations or during power up power down operations.

A signal processing system may include a signal path and a chop management circuit. The signal path may comprise a chopper configured to chop a differential input signal to the signal path at a chopping frequency and a low-pass filter downstream of the chopper and configured to filter out intermodulation products of a direct current offset of the signal path and intermodulation products of an aggressor on the differential input signal in order to generate an output signal. The chop management circuit may be communicatively coupled to the chopper and configured to, based on operational parameters associated with the signal path, dynamically manage energy of one or more clock signals used to define the chopping frequency.

A power amplifier includes: at least two first bridge type amplifying circuits and at least two second bridge type amplifying circuits; the negative pole of the first load of each first bridge type amplifying circuit is respectively coupled to the positive stage of the second load of each second bridge type amplifying circuits through a gating circuit. When both a first input signal input into one of the at least two first bridge type amplifying circuits and a second input signal input into one of the at least two second bridge type amplifying circuits are less than a preset threshold, the gating circuit is turned on, so that the one of the at least two first bridge type amplifying circuits and the one of the at least two second bridge type amplifying circuits can share load current by the gating circuit.

In accordance with embodiments of the present disclosure, a multi-mode switching power converter may include a power inductor, a first switch coupled between a first terminal of the power inductor and a first supply terminal having a first voltage, a second switch coupled between the first terminal of the power inductor and a second supply terminal having a second voltage, a full bridge comprising a plurality of switches and having an output for producing the output voltage comprising a first output terminal and a second output terminal, wherein a first input of the full bridge is coupled to a second terminal of the power inductor and a second input of the full bridge is coupled to one of the first supply terminal and the second supply terminal, and a capacitor coupled between the first output terminal and the second output terminal.

A speaker device includes left and right speakers and a correction part. The correction part corrects frequency characteristics of a stereo audio signal supplied to the left and right speakers so that transfer characteristics of the left and right speakers become predetermined transfer characteristics.

A method may be provided for powering up or down a playback path comprising a digital-to-analog converter (DAC) for generating a non-ground-centered analog intermediate voltage centered at a common-mode voltage and coupled to a driver for generating a ground-centered playback path output voltage at an output of the driver wherein the output of the driver is clamped via a finite impedance to a ground voltage. The method may include transitioning continuously or in a plurality of discrete steps the analog intermediate voltage from an initial voltage to the common-mode voltage such that the transitioning is substantially inaudible at the output of the driver. A method for operating an output clamp of an output driver stage of a playback path may include transitioning continuously or in a plurality of discrete steps an impedance of the output clamp in order to match an output offset of the output driver stage in order to minimize audio artifacts appearing at an output of the output driver stage.