Circuitry for driving a load, the circuitry comprising: driver circuitry; and load sensing circuitry, wherein the circuitry is operable in: a driving mode of operation in which the driver circuitry supplies a drive signal to a load coupled to the circuitry; and a load sensing mode of operation, for estimating a characteristic of a load coupled to the circuitry based on a signal output by the load sensing circuitry in response to a stimulus signal, wherein the circuitry is configured to, in response to a request for operation of the circuitry in the load sensing mode: compare an indication of a current through the load to a predefined threshold; and if the indication of the current through the load meets the predefined threshold, prevent or delay operation in the load sensing mode.

Integrated circuitry implementing amplifier circuitry, the integrated circuitry comprising first amplifier circuitry and second amplifier circuitry, the first and second amplifier circuitry being configurable as first and second single-ended amplifiers or as a differential amplifier, wherein the first amplifier circuitry comprises: a first input stage; a first half-bridge output stage having an output coupled to a first output terminal of the integrated circuitry; a first feedback path coupling a first input of the first input stage to a first sense terminal of the first amplifier circuitry; a second feedback path coupling a second input of the first input stage to a second sense terminal of the first amplifier circuitry; and a first shunt resistor coupling the output of the first half-bridge output stage to the first feedback path, wherein the second amplifier circuitry comprises: a second input stage; and a second half-bridge output stage having an output coupled to a second output terminal of the integrated circuitry, and wherein the first amplifier circuitry further comprises a second shunt resistor coupling the second feedback path to a dedicated shunt resistor terminal of the integrated circuitry, such that the second shunt resistor is directly accessible from outside the integrated circuitry.

Audio amplifier circuit includes a pulse width modulation circuit, an auxiliary loop circuit corresponding to a first variable resistance value and a first variable current value, and a main loop circuit corresponding to a second variable resistance value and a second variable current value. Main loop circuit is coupled between a second node, an output terminal, and a first node. Under a condition that auxiliary loop circuit and main loop circuit are turned on, second variable resistance value is decreased and second variable current value is increased after auxiliary loop circuit enters into a first control state, such that main loop circuit enters into a second control state. First variable resistance value is increased and first variable current value is decreased after main loop circuit enters into second control state, such that auxiliary loop circuit is out of first control state.

Various implementations include a common mode voltage controller for a self-boosting push pull amplifier. In some implementations, input signal are processed by: calculating, based upon the input signal, a maximum duty cycle to achieve a target differential in an output of the self-boosting push pull amplifier; calculating, based on the input signal, a set of control parameters associated with adjusting a common mode voltage of the output; and generating, based on the input signal, a pair of signals configured to adjust the common mode voltage of the output, wherein the pair of signals include a gain adjustment and offset based on the maximum duty cycle and the set of control parameters, and wherein the pair of signals are configured to maintain the target differential in the output of the self-boosting push pull amplifier as the common mode voltage is adjusted to a different operating point.

Certain aspects of the present disclosure generally relate to an amplifier configured to process signals received in different frequency bands, where at least a portion of the amplifier is shared between different modes corresponding to the different frequency bands. One example circuit generally includes an amplifier having at least one first transistor configured to amplify a first signal received in a first mode of operation (e.g., associated with a particular frequency band), and at least one second transistor configured to amplify a second signal received in a second mode of operation. The amplifier may also include a transformer comprising a primary winding and a secondary winding, and one or more switches configured to selectively couple the primary winding to the first transistor or the second transistor based on the first mode or the second mode of operation, respectively. In certain aspects, the transformer may be coupled to a transconductance circuit.

A power amplifier includes a common source amplifier and a common gate amplifier circuit. The common source amplifier circuit has a terminal connected to a radio frequency (RF) input terminal and uses a source terminal commonly as an input terminal and an output terminal of the power amplifier. The common gate amplifier circuit has a terminal connected to the common source amplifier circuit and another terminal connected to an RF output terminal, and uses a gate terminal commonly as the input terminal and the output terminal of the power amplifier. The common gate amplifier circuit includes a Doherty amplifier including a main power amplifier and an auxiliary power amplifier that is connected to the main power amplifier in parallel.

An audio signal amplification device of the disclosure includes: a delta-sigma modulation part configured to resample an input digital audio signal with a quantization number smaller than a quantization number of the digital audio signal; a pulse-width modulation part configured to convert an output signal from the delta-sigma modulation part into a pulse-width modulation signal which sets a gradation of the output signal in an amplitude direction at a gradation of a pulse width; a power amplification part configured to perform power amplification on an output signal from the pulse-width modulation part; a low-pass filter configured to diminish a component higher than a predetermined cutoff frequency, in an output signal from the power amplification part, and to output the resultant signal; and a correction processing part configured to generate a correction signal for correcting the digital audio signal. The correction processing part includes a switch configured to control coupling of the correction processing part to the low-pass filter. When the switch is on, the correction processing part couples a loudspeaker to the low-pass filter, and generates the correction signal.

A driver interface for a switch-based circuit includes an AC coupling capacitor, a first diode or a first series of diodes, and a second diode or a second series of diodes connected in series with the first diode or first series of diodes but with an opposing polarity. The AC coupling capacitor removes a DC voltage from an input bi-level drive signal that does not have the appropriate high and low drive levels needed to switch a FET in the switch-based circuit between fully ON and fully OFF states. The first diode or first series of diodes and the second diode or second series of diodes clamp the resulting AC-coupled drive signal to produce an output bi-level drive signal having the high and low drive levels needed to switch the FET between fully ON and fully OFF states. The driver interface maintains the high and low drive levels of the output bi-level drive signal irrespective of any changes made to the duty cycle or pulse density of the input bi-level drive signal.

Circuits for protecting devices, such as gallium nitride (GaN) devices, and operating methods thereof are described. The circuits monitor a magnitude of the current in a device and reduce the magnitude of the current and/or shut down the device responsive to the magnitude of the current exceeding a threshold. These circuits safeguard devices from damaging operating conditions to prolong the operating life of the protected devices.

An audio signal modulation and amplification circuit includes a common-mode electric potential controller, a carrier generator, and channel circuits. The common-mode electric potential controller is configured to generate one or more first common-mode electric potentials and second common-mode electric potentials. The carrier generator is adapted to receive the first common-mode electric potential to generate a carrier signal. Each of the channel circuits includes a filter, a comparison circuit, and a driving circuit. The filter is adapted to filter an input signal and generate a filtered signal based on a corresponding one of the second common-mode electric potentials. The comparison circuit is configured to compare the potential of the carrier signal with the potential of the filtered signal to generate a pulse-width modulation signal. The driving circuit is configured to be turned on or off in response to the pulse-width modulation signal to output a load driving signal.