The invention relates to a method for controlling a driver circuit. The method comprises operating an amplifier for providing an output signal, for example an electronic signal for driving or controlling a load, for example a voltage or a current, based on a control signal. The method further comprises operating a comparator for providing the control signal by comparing an input signal, for example an electronic signal with a lower level or a lower amplitude than the output signal, to a feedback signal, wherein the feedback signal is based on the output signal. The method further comprises providing a first supply voltage to the comparator, and providing a second supply voltage to the amplifier, wherein the second supply voltage is higher than the first supply voltage.

The present invention discloses a loudspeaker system and an electronics device. The loudspeaker system comprises: a power amplifier, which amplifies an input audio signal; a transducer, connected to the power amplifier, which receives the amplified input audio signal and converts it into a sound wave; a power supply, which provides current to the power amplifier; and a secondary battery, wherein the secondary battery provides extra current to the power amplifier when the power amplifier needs a higher current to actuate the transducer.

An amplifier for driving a display panel includes an input stage, a gain stage and an output stage. The gain stage is coupled to the input stage. The output stage, coupled to the gain stage, includes a first output driving circuit and a second output driving circuit. The first output driving circuit is operated in a first voltage domain. The second output driving circuit is operated in a second voltage domain different from the first voltage domain.

Average power tracking (APT) systems with fast transient settling are disclosed. In certain embodiments, an APT system is used to provide a power amplifier supply voltage to a power amplifier that amplifies a radio frequency (RF) signal. The APT system controls the power amplifier supply voltage to track an average power of the RF signal, and generates a first regulated voltage based on a first average power tracking voltage level and a second regulated voltage based on a second average power tracking voltage level. The APT system includes a DC switch configured to receive the first regulated voltage and the second regulated voltage, and operable to change state to transition the power amplifier supply voltage from the first average power tracking voltage level to the second average power tracking voltage level.

Average power tracking (APT) systems with fast transient settling are disclosed. In certain embodiments, an APT system is used to provide a power amplifier supply voltage to a power amplifier that amplifies a radio frequency (RF) signal. The APT system controls the power amplifier supply voltage to track an average power of the RF signal, and includes a DC-to-DC converter that is assisted by an error amplifier in transitioning from one power amplifier supply voltage level to another power amplifier supply voltage level. Thus, the combination of a DC-to-DC converter with a fast changing error amplifier can swing enough AC voltage with a low enough slew rate to be able to rapidly transition the power amplifier supply voltage from one APT voltage level to another APT voltage level.

Power amplifier systems with non-linear antenna impedance for load compensation are provided. In certain embodiments, a method of power amplification in a mobile device is provided. The method includes generating a radio frequency input signal using a transceiver, amplifying the radio frequency input signal to generate a radio frequency output signal using a power amplifier, and transmitting the radio frequency output signal using an antenna, including compensating the power amplifier for a change in output load in response to a change in signal power using a non-linear impedance versus output power characteristic of the antenna.

A smart speaker power controller may be configured to receive power conforming to one of a plurality of power modes from an input power source. The power controller may be further configured to communicate the power mode to at least one component of a processing system or at least one component of an audio system for operating the smart speaker according to the received power mode, including determining a current limit of a power converter; determining a shutdown voltage threshold and safely shutting down the smart speaker if the input voltage falls below the threshold, and/or modifying audio operation of the smart speaker in response to the power mode. The smart speaker can further include an audio power supply controller configured to monitor energy required to reproduce an audio signal and to servo a power supply voltage provided to an audio amplifier in response to this energy level.

A power management circuit operable to adjust voltage within a defined interval(s) is provided. The power management circuit is configured to generate a time-variant voltage for amplifying an analog signal based on a target voltage. In embodiments disclosed herein, the power management circuit can be configured to generate a lower initial target voltage at a start of the defined interval(s), such as during a cyclic prefix (CP) of an orthogonal frequency division multiplexing (OFDM) symbol, and dynamically adjust the initial target voltage, if necessary, within the defined interval(s) based on a time-variant power envelope of the analog signal. By generating the lower target voltage, in contrast to a conventional method of generating a maximum target voltage, at the start of the defined interval(s), it is possible to reduce energy waste and help improve efficiency in a power amplifier configured to amplify the analog signal based on the time-variant voltage.

A system may include a charge pump configured to boost an input voltage of the charge pump to an output voltage greater than the input voltage, a current mode control loop for current mode control of a power amplifier powered by the output voltage of the charge pump, and a controller configured to, in a current-limiting mode of the controller, control an output power of the charge pump to ensure that an input current of the charge pump is maintained below a current limit, control the power amplifier by placing the power amplifier into a high-impedance mode during the current-limiting mode, and control state variables of a loop filter of the current mode control loop during the current-limiting mode.

A signal amplifying circuit and associated methods and apparatuses, the circuit comprising: a signal path extending from an input terminal to an output terminal, a gain controller arranged to control the gain applied along the signal path in response to a control signal; an output stage within the signal path for generating the output signal, the output stage having a gain that is substantially independent of its supply voltage, and a variable voltage power supply comprising a charge pump for providing positive and negative output voltages, the charge pump comprising a network of switches that is operable in a number of different states and a controller for operating the switches in a sequence of the states so as to generate positive and negative output voltages together spanning a voltage approximately equal to the input voltage.