An audio output device includes PWM output devices, a weighting unit, a mixer, and an amplifier. The PWM output devices divide audio data into multiple parts including an upper bit part to a lower bit part, and output the multiple parts of the audio data as PWM outputs. The weighting unit weights the PWM outputs from the PWM output devices. The mixer synthesizes the PWM outputs after being weighted. The amplifier supplies an electric current to a sounding body in accordance with a synthesis result by the mixer to cause the sounding body to emit a sound.

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.

Systems and methods are provided for amplifying multiple input signals to generate multiple output signals. An example system includes a first channel, a second channel, and a third channel. The first channel is configured to receive one or more first input signals, process information associated with the one or more first input signals and a first ramp signal, and generate one or more first output signals. The second channel is configured to receive one or more second input signals, process information associated with the one or more second input signals and a second ramp signal, and generate one or more second output signals. The first ramp signal corresponds to a first phase. The second ramp signal corresponds to a second phase. The first phase and the second phase are different.

This invention provides compact Power Amplifiers with improved efficiency of the circuitry and improved heat dissipation, together achieved much smaller enclosure size for use in modern installations requiring reduced height such as between the thin flat TV and wall, under the table or on the projector pole or in ceiling box and the like.

A liquid ejecting apparatus includes a liquid ejecting head ejecting a liquid by supplying a drive signal to a drive element, and a drive circuit that outputs the drive signal. The drive circuit includes an integrated circuit that outputs an amplification control signal, an amplifier circuit that output an amplified modulation signal, and a demodulation circuit that output the drive signal. The integrated circuit includes a modulation circuit that modulates the base drive signal to output a modulation signal, a switching circuit that outputs the amplification control signal according to the modulation signal, and a constant voltage output circuit that outputs a DC voltage signal based on the output of the modulation circuit. The constant voltage output circuit and the modulation circuit are electrically coupled to each other, and at least a part of the constant voltage output circuit is located between the modulation circuit and the switching circuit.

A voltage converter comprising: a bootstrap circuit, comprising an output capacitor, an error amplifier, a charging control circuit and a charging circuit. The charging control circuit comprises: a detection circuit, configured to detect an output voltage of the output capacitor to generate a detection signal; and a power limiting circuit, configured to clamp an output voltage of the error amplifier to a specific range based on the detection signal . The charging circuit is configured to generate a charging signal according the output voltage of the error amplifier to the bootstrap circuit, to charge the output capacitor.

The present technology relates to an amplifier and a signal processing circuit that can reduce deterioration of signal quality. A voltage-to-time converter (VTC) integrates error information included in an output pulse width modulation (PWM) signal that is a PWM signal to be output to an outside of a device, so as to convert the error information into error time information. A delay unit generates a plurality of delayed signals using an input PWM signal that is a PWM signal input from the outside of the device. A signal selection unit selects a delayed signal according to the error time information from the plurality of delayed signals and outputs the output PWM signal. The present disclosure can be applied to, for example, an audio player.

A nuclear magnetic resonance (NMR) power supply system and method are disclosed. The architecture adopts a two-stage topology to reduce the required capacitance by over ten times, leading to a four-fold improvement in power density. The first stage is an isolated converter that only supplies average power, therefore input filter and transformer sizes can be reduced. The second stage is a fast response DC-DC converter followed by a RF transmitter to produce a pulsed RF signal, so that the mid-point voltage after the first stage can be allowed to droop considerably, leading to much smaller sized capacitors. These and other embodiments enforce the isolated converter to only transfer average power, which reduces the power rating and the volume of the system's transformer.

A system may include a Class-D stage comprising a first high-side switch coupled between a supply voltage and a first output terminal of the Class-D stage, a second high-side switch coupled between the supply voltage and a second output terminal of the Class-D stage, a first low-side switch coupled between a ground voltage and the first output terminal, and a second low-side switch coupled between the ground voltage and the second output terminal. The system may also include current sensing circuitry comprising a sense resistor, such that an output current through a load coupled between the first output terminal and the second output terminal causes a first sense voltage proportional to the output current across the sense resistor. The system may additionally include a modulator for generating a differential pulse-width modulation driving signal to the first high-side switch, the second high-side switch, the first low-side switch, and the second low-side switch and pilot tone injection circuitry configured to inject a periodic pilot tone into the differential pulse-width modulation driving signal at a pilot tone frequency.

According to one embodiment, a clipping state detecting circuit includes: a zero-cross detection circuit that detects a zero-cross point of an input signal; an output circuit that converts the input signal into a PWM signal; a clip detection circuit that detects a state in which an output of the output circuit is clipped; and a control circuit that determines a state is a clipping state when a clip time of the output of the output circuit satisfies a condition of a threshold value set in advance with respect to a non-clip time.