Various implementations include systems for amplifying input signals. In particular implementations, a system includes a common mode voltage controller configured to receive an input signal and output a pair of adjusted signals; a modulator that generates a pair of pulse width modulation (PWM) signals in response to the adjusted signals; and a self-boosting push pull amplifier configured to receive the PWM signals and generate an amplified output, wherein the self-boosting push pull amplifier is configured to generate a differential mode voltage representative of an amplified version of the input signal, wherein the adjusted audio signals generated by the common mode voltage controller include a dynamically adjusted gain and duty cycle offset that causes the self-boosting push pull amplifier to operate with a reduced common mode voltage.

An improved method of providing high burst power to audio amplifiers from limited power sources, using parallel power paths to increase system efficiency without need for a power path controller, thus utilizing a simplified circuit operation and maximizing average power available for both the amplifier and supporting circuitry.

Various embodiments of the present technology may comprise methods and apparatus for an amplifier circuit. Methods and apparatus for an amplifier circuit according to various aspects of the present invention may be utilized in a digital-to-analog converter. The amplifier circuit may comprise a first operational amplifier with a feedback circuit. The feedback circuit may comprise an inverting amplifier circuit.

A circuit includes a digital-to-analog conversion circuit, an amplifying circuit, a mixing circuit, and an analog-to-digital converter. The digital-to-analog conversion circuit is configured to receive and convert audio data in the digital domain and output audio data in the analog domain. The audio data includes a main-tone component. The amplifying circuit is configured to output an audio signal according to the audio data in the analog domain. The mixing circuit is configured to eliminate the main-tone component according to the audio data in the analog domain and the audio signal and to output a feedback signal. The analog-to-digital converter is configured to convert the feedback signal from the analog domain to the digital domain.

The present invention provides a signal processing device that allows a user, who adjusts a signal level to match a reference level, to adjust the signal level while checking a degree of difference between the signal level and the reference level. A signal processing device according to the present invention comprises: an input part 20 to which an input signal is input; a storage 40 that stores therein one or more setting values of a parameter to be used for amplifying the input signal and a reference value of the setting value; an amplification part 30 that generates an output signal by amplifying a level of the input signal based on the setting value; an output part 70 that outputs the output signal; an adjustment part 50 that adjusts the setting value; and a display 60 that displays a display result determined based on the setting value adjusted by the adjustment part and the reference value. The display result displayed on the display 60 includes: a specific display result displayed when a relation between the setting value and the reference value is a specific relation; and a non-specific display result displayed when the relation between the setting value and the reference value is different from the specific relation.

The present invention provides a signal processing device that allows a user, who adjusts a signal level to match a reference level, to adjust the signal level while checking a degree of difference between the signal level and the reference level.

A signal processing device according to the present invention comprises: an input part 20 to which an input signal is input; a storage 40 that stores therein one or more setting values of a parameter to be used for amplifying the input signal and a reference value of the setting value; an amplification part 30 that generates an output signal by amplifying a level of the input signal based on the setting value; an output part 70 that outputs the output signal; an adjustment part 50 that adjusts the setting value; and a display 60 that displays a display result determined based on the setting value adjusted by the adjustment part and the reference value. The display result displayed on the display 60 includes: a specific display result displayed when a relation between the setting value and the reference value is a specific relation; and a non-specific display result displayed when the relation between the setting value and the reference value is different from the specific relation.

A power output circuit supplies an audio power output signal that is adjusted to prevent clipping when needed based on an estimate of available energy from the power supply supplying the power output circuit. The power output circuit may be an audio power output circuit that generates an audio power output signal from samples of an audio program that are stored in a buffer. A processing block determines an energy requirement for producing the audio power output signal from the audio program and adjusts an amplitude of the audio power output signal in conformity with the determined energy requirement and an available energy determined for the power supply so that the audio power output signal is reproduced without clipping of the audio power output signal.

An error amplifier for a pulse width modulation circuit is described. The amplifier includes an operational amplifier configured as an integrator and a feedback loop coupled between a signal output of the operational amplifier and an inverting input of the operational amplifier. The feedback loop comprises a feedback capacitor coupled to the signal output, a feedback resistor coupled to the feedback capacitor, and an integrator resistor coupled to the feedback resistor and the inverting input of the operational amplifier. A junction between the feedback resistor and the integrator resistor is configured to receive an input signal and a junction between the feedback capacitor and the feedback resistor is configured to receive a feedback signal from the pulse width modulation circuit.

An improved method of providing high burst power to audio amplifiers from limited power sources, using parallel power paths to increase system efficiency without need for a power path controller, thus utilizing a simplified circuit operation and maximizing average power available for both the amplifier and supporting circuitry.

Example embodiments provide a process that includes one or more of receiving an audio signal at a feedback compressor circuit, determining how much to attenuate the audio signal when a power level of the audio signal exceeds a threshold power level, combining the audio signal with an auxiliary attenuation signal from an auxiliary attenuation source and a compressed attenuation signal from the feedback compressor circuit to create a combination signal, and generating an audio output signal of the feedback compressor circuit based on the combination signal.