Abstract: A Class-D audio amplifier includes a triangular wave generator, a wave reshaping device and a pulse-width modulator. The triangular wave generator generates a first triangular wave. The wave reshaping device generates a second triangular wave by reshaping the first triangular wave. The pulse-width modulator modulates a pair of differential audio input waves with the second triangular wave instead of the first triangular wave to reduce a switching loss of the Class-D audio amplifier.

Abstract: A noise elimination device for a Class-D audio amplifier includes a residual signal detector and a multiplexer, wherein the multiplexer is electrically connected with a sigma-delta modulator (SDM) and a pulse width modulator (PWM) of the Class-D audio amplifier and the residual signal detector. The residual signal detector is configured to detect whether an input signal of the Class-D audio amplifier is residual. The multiplexer is configured to output zero data into the pulse width modulator when the residual signal detector detects that the input signal of the Class-D audio amplifier is residual.

Abstract: Circuit, method for audio signal processing with excursion estimation compensation, and non-transitory storage medium are provided. The circuit comprises a delay circuit, compensation filter, excursion estimator, peak detector, gain determination circuit, and gain adjustment circuit. The delay circuit is for delaying a digital audio signal to output a delayed digital audio signal. The compensation filter is for generating a compensated digital audio signal according to the digital audio signal for excursion estimation compensation for a speaker type. The excursion estimator is for determining an estimated excursion signal for the speaker type according to the compensated digital audio signal. The gain determination circuit is for generating a gain setting signal according to the estimated excursion signal and a threshold value. The gain adjustment circuit is for generating an adjusted digital audio signal according to the gain setting signal and delayed digital audio signal.

Abstract: A device includes a carbon nanotube having a channel region and dopant-free source/drain regions at opposite sides of the channel region, a first metal oxide layer interfacing a first one of the dopant-free source/drain regions of the carbon nanotube, a second metal oxide layer interfacing a second one of the dopant-free source/drain regions of the carbon nanotube and a gate structure over the channel region of the carbon nanotube, and laterally between the first metal oxide layer and the second metal oxide layer.

Abstract: A device for audio signal processing includes a main processor and two audio processors electrically connected with the main processor. Each audio processor corresponds to a channel of a stereo audio output. The main processor provides an indication signal for the two audio processors. Each audio processor generates a synchronization signal according to the indication signal and performs audio signal processing according to the synchronization signal. The synchronization signals begin simultaneously and have the same frequencies that equal a sampling frequency. Each synchronization signal includes at least one pulse, and a start of each pulse of each synchronization signal is aligned in time with a start of a pulse of the indication signal. The audio signal processing performed by each audio processor begins at an end of one of the at least one pulse in the synchronization signal corresponding to the audio processor.

Abstract: An apparatus for noise reduction in audio signal processing includes a power amplifier, a zero-crossing detector, and a threshold detector. The power amplifier has an input signal terminal for receiving an audio input signal and an output signal terminal. The audio input signal is a digital-to-analog converted version according to a version of a digital audio signal. The power amplifier has an analog gain which is controllable in response to an analog gain control signal. The zero-crossing detector determines a zero-crossing detection signal according to an internal signal provided between the input signal terminal and the output signal terminal. The threshold detector determines a gain setting according to the digital audio signal and the zero-crossing detection signal to generate the analog gain control signal indicating the gain setting, wherein the threshold detector controls the analog gain of the power amplifier according to the analog gain control signal.

Abstract: An apparatus for noise reduction in audio signal processing includes a power amplifier, a zero-crossing detector, and a threshold detector. The power amplifier has an input signal terminal for receiving an audio input signal and an output signal terminal. The audio input signal is a digital-to-analog converted version according to a version of a digital audio signal. The power amplifier has an analog gain which is controllable in response to an analog gain control signal. The zero-crossing detector determines a zero-crossing detection signal according to an internal signal provided between the input signal terminal and the output signal terminal. The threshold detector determines a gain setting according to the digital audio signal and the zero-crossing detection signal to generate the analog gain control signal indicating the gain setting, wherein the threshold detector controls the analog gain of the power amplifier according to the analog gain control signal.

Abstract: A parametric equalizer includes an equalizer circuit, a first protection circuit, a second protection circuit, and a first addition circuit. The equalizer circuit is arranged to receive an input signal, and process the input signal to generate an output signal. The first protection circuit is arranged to generate a first protection signal according to the output signal, the input signal, and a first processed signal. The second protection circuit is arranged to generate a second protection signal according to the input signal and a second processed signal. The first addition circuit is coupled to the first protection circuit and the second protection circuit, and is arranged to combine the first protection signal and the second protection signal to generate an equalizer output signal.

Abstract: A parametric equalizer includes an equalizer circuit, a first protection circuit, a second protection circuit, and a first addition circuit. The equalizer circuit is arranged to receive an input signal, and process the input signal to generate an output signal. The first protection circuit is arranged to generate a first protection signal according to the output signal, the input signal, and a first processed signal. The second protection circuit is arranged to generate a second protection signal according to the input signal and a second processed signal. The first addition circuit is coupled to the first protection circuit and the second protection circuit, and is arranged to combine the first protection signal and the second protection signal to generate an equalizer output signal.

Abstract: A switch circuit provides a first output signal and a second output signal for switching between ternary modulation and quaternary modulation for a target device. A first output signal is provided from one of a first signal, a second signal and a ground signal according to an input signal and a duty signal, wherein the first signal is generated through performing a one-bit left-shift operation for the input signal, and the second signal is generated through adding the input signal and the duty signal. A second output signal is provided from one of a third signal, a fourth signal and the ground signal according to the input signal and the duty signal, wherein the third signal is generated through subtracting the input signal from the duty signal, and the fourth signal is generated through performing a two's-complement transformation and the one-bit left-shift operation for the input signal.

Abstract: A direct current (DC) offset protection circuit includes: a DC offset detection circuit and a control circuit. The DC offset detection circuit is arranged to detect whether a DC component exists in pulse-width-modulation (PWM) signals and accordingly generate a DC offset detection result. The control circuit is arranged to control an audio system according to the DC offset detection result. The DC offset detection circuit comprises a PWM polarity judgment circuit, a cascaded integrator-comb (CIC) filter and a DC offset judgment circuit. The PWM polarity judgment circuit is arranged to judge a polarity of complementary PWM signals and accordingly generate a polarity indication value. The CIC filter is arranged to generate a filter output signal by averaging a plurality of polarity indication values. The DC offset judgment circuit is arranged to generate the DC offset detection result by comparing the filter output signal with a predetermined DC threshold.

Abstract: A virtual bass generating circuit used in a speaker is used to filter out a high frequency part of an audio signal to generate a low passed audio signal, generates an even and odd audio signals respectively having even and odd harmonics of the low passed audio signal according to the low passed audio signal, subtracts an amplified low passed audio signal from an addition of an amplified even audio signal and an amplified odd audio signal to generate a first calculated audio signal, filters out a low frequency part and a high frequency part of the first calculated audio signal to generate a band passed audio signal, and adds the band passed audio signal and the audio signal to generate a second calculated audio signal with enhanced even and odd harmonics of the audio signal.

Abstract: A virtual bass generating circuit used in a speaker is used to filter out a high frequency part of an audio signal to generate a low passed audio signal, generates an even and odd audio signals respectively having even and odd harmonics of the low passed audio signal according to the low passed audio signal, subtracts an amplified low passed audio signal from an addition of an amplified even audio signal and an amplified odd audio signal to generate a first calculated audio signal, filters out a low frequency part and a high frequency part of the first calculated audio signal to generate a band passed audio signal, and adds the band passed audio signal and the audio signal to generate a second calculated audio signal with enhanced even and odd harmonics of the audio signal.

Abstract: An exemplary embodiment of the present disclosure illustrates a modulation method for a switching modulator. Firstly, a data signal is received. Then, a first output signal at a first output side of the switching modulator and a second output signal at a second output side of the switching modulator are generated according to the data signal received, wherein the first output signal is an addition signal of a first pulse signal and the data signal, the second output signal is a second pulse signal, the first pulse signal and the second pulse signal are aligned to a same pulse width, and the pulse width equals to a minimum resolution of the switching modulator.

Abstract: An exemplary embodiment of the present disclosure illustrates a modulation method for a switching modulator. Firstly, a data signal is received. Then, a first output signal at a first output side of the switching modulator and a second output signal at a second output side of the switching modulator are generated according to the data signal received, wherein the first output signal is an addition signal of a first pulse signal and the data signal, the second output signal is a second pulse signal, the first pulse signal and the second pulse signal are aligned to a same pulse width, and the pulse width equals to a minimum resolution of the switching modulator.

Abstract: The trampoline contains a flexible jumping bed enclosed by a closed frame supported by a number of legs on the ground. A cushion element such as a spring, a rubber block, or a hydraulic or air buffering device is provided at each connection between the frame and the legs. The cushion element absorbs part of the downward force exerted on the frame and the legs so that an extended operation life of the trampoline is achieved.

Abstract: A swimming pool assembly includes a plurality of connectors, a plurality of struts, and a plurality of horizontal poles of a rhombic cross-section. After connecting the horizontal poles to engagement slots of the connectors, the structural strength of the swimming pool assembly can be considerably increased. Spring retaining pin elements are disposed inside the horizontal poles at both ends to engage positioning poles of the connectors so as to achieve firm connection. The connectors are further provided with canopy pole insert holes for mounting a canopy framework. The canopy framework can be formed by utilizing a plurality of canopy poles, a connecting tube seat, and a canopy. A sprinkling structure including L-shaped bent pipes disposed inside the engagement slots of the connectors can further be installed on the swimming pool framework.