An amplifier circuit includes an output terminal, an amplification unit and a switch. The output terminal is used to output an amplification signal. The amplification unit includes a first transistor and a second transistor. The first transistor includes a control terminal for receiving a first input signal, a first terminal coupled to the output terminal for outputting an amplified first input signal, and a second terminal. The second transistor includes a control terminal for receiving a second input signal, a first terminal coupled to the output terminal for outputting an amplified second input signal, and a second terminal. The switch includes a first terminal coupled to the second terminal of the first transistor, and a second terminal. The amplification signal is generated using at least the amplified first input signal and/or the amplified second input signal.

An amplifier circuit is provided that includes an amplifier having a signal input and a signal output, the amplifier being configured to produce an amplified signal at the signal output, a feedback path coupled between the signal output and the signal input, and an amplifier linearity boost circuit positioned in the feedback path. The amplifier linearity boost circuit includes a non-linear current generator and a phase-shifting circuit, the non-linear current generator being configured to provide a non-linear current based on the amplified signal, and the phase-shifting circuit being configured to adjust a phase of the non-linear current to reduce an intermodulation distortion of the amplified signal.

An amplifier circuit is provided that includes an amplifier having a signal input and a signal output, the amplifier being configured to produce an amplified signal at the signal output, a feedback path coupled between the signal output and the signal input, and an amplifier linearity boost circuit positioned in the feedback path. The amplifier linearity boost circuit includes a non-linear current generator and a phase-shifting circuit, the non-linear current generator being configured to provide a non-linear current based on the amplified signal, and the phase-shifting circuit being configured to adjust a phase of the non-linear current to reduce an intermodulation distortion of the amplified signal.

Systems and methods include a circuit having a plurality of integrator circuits arranged in series and configured to receive an input signal at a first of the plurality of integrators and generate an output signal at a last of the plurality of integrators, a filter arranged to receive a feedback signal comprising the output signal and generate a filtered feedback signal, which is applied to the input signal before input to the first of the plurality of integrators, and a feedback signal path configured to receive the feedback signal and apply the feedback signal to an input of a second of the plurality of integrators. The circuit may include a class-D amplifier and/or a delta-sigma modulator. The input signal may include an analog audio signal that is amplifier to drive an audio speaker.

Systems and methods include a circuit having a plurality of integrator circuits arranged in series and configured to receive an input signal at a first of the plurality of integrators and generate an output signal at a last of the plurality of integrators, a filter arranged to receive a feedback signal comprising the output signal and generate a filtered feedback signal, which is applied to the input signal before input to the first of the plurality of integrators, and a feedback signal path configured to receive the feedback signal and apply the feedback signal to an input of a second of the plurality of integrators. The circuit may include a class-D amplifier and/or a delta-sigma modulator. The input signal may include an analog audio signal that is amplifier to drive an audio speaker.

An amplifier includes an input circuit configured to receive an analog input signal and a feedback signal, and output an analog error signal based on the analog input signal and the feedback signal. An ADC is configured to convert the analog error signal into a digital signal in a phase domain. A digital control circuit is configured to generate a digital control signal based on the digital signal in the phase domain. An output circuit is configured to generate an amplified output signal based on the digital control signal, and a feedback circuit is configured generate the feedback signal based on the amplified output signal.

An amplifier includes an input circuit configured to receive an analog input signal and a feedback signal, and output an analog error signal based on the analog input signal and the feedback signal. An ADC is configured to convert the analog error signal into a digital signal in a phase domain. A digital control circuit is configured to generate a digital control signal based on the digital signal in the phase domain. An output circuit is configured to generate an amplified output signal based on the digital control signal, and a feedback circuit is configured generate the feedback signal based on the amplified output signal.

An audio output device includes a processor, an audio decoder, an audio amplifier, and a protection circuit. The processor outputs an audio digital signal. The audio decoder converts the audio digital signal into an audio analog signal. The audio amplifier amplifies the audio analog signal. The protection circuit detects abnormalities in the audio digital signal or the amplified audio analog signal. When the audio digital signal or the amplified audio analog signal is abnormal, the protection circuit outputs a disable signal to turn off or mute the audio amplifier, or the protection circuit outputs a logic signal to notify the processor, so that the processor outputs the disable signal to turn off or mute the audio amplifier.

A power supply includes a first DC-DC converter coupled to receive power from a first power source, a second DC-DC converter coupled to receive power from a second power source, and a control block. The first DC-DC converter is operable to generate a regulated power supply voltage on an output node of the power supply. The first power source has a maximum output current limit. The second DC-DC converter is also operable to generate a regulated power supply voltage on the output node. The control block is designed to generate the regulated power supply voltage based on both of the first DC-DC converter and the second DC-DC converter.

A power supply includes a first DC-DC converter coupled to receive power from a first power source, a second DC-DC converter coupled to receive power from a second power source, and a control block. The first DC-DC converter is operable to generate a regulated power supply voltage on an output node of the power supply. The first power source has a maximum output current limit. The second DC-DC converter is also operable to generate a regulated power supply voltage on the output node. The control block is designed to generate the regulated power supply voltage based on both of the first DC-DC converter and the second DC-DC converter.