Abstract: A system may include a signal processor that receives a first input signal from a first channel switching amplifier of a multi-channel amplifier and a second input signal from a second channel switching amplifier of the multi-channel amplifier, wherein the first channel switching amplifier and the second channel switching amplifier share a capacitor that has a first terminal coupled to a common terminal that is coupled to a first negative polarity of the first channel switching amplifier and a second positive polarity of the second channel switching amplifier and a second terminal that is coupled to a ground. The signal processor may be configured to receive the first input signal and the second input signal and modify the first input signal into the first channel switching amplifier and the second input signal into the second channel switching amplifier to regulate a common mode signal at the common terminal.

Abstract: This application relates to methods and apparatus for driving a transducer with switching drivers. A driver circuit has first and second switching drivers for driving the transducer in a bridge-tied-load configuration, each of the switching drivers having a respective output stage for controllably switching the respective driver output node between high and low switching voltages with a controlled duty cycle. Each of switching drivers is operable in a plurality of different driver modes, wherein the switching voltages are different in said different driver modes. A controller controls the driver mode of operation and the duty cycle of the switching drivers based on the input signal. The controller is configured to control the duty cycles of the first and second switching drivers within defined minimum and maximum limits of duty cycles; and to transition between driver modes of operation when the duty cycle of one of the switching drivers reaches a duty cycle limit.

Abstract: Methods and systems for determining clock signals for audio processing using different operating modes are provided. In one aspect, a transition control word is determined to transition from a first control word for a first operating mode to a second control word for the second operating mode. The transition control word may be used to process the received audio signal while transitioning between the operating modes. After the transition, the second control word may be used to process the received audio signal using the second operating mode. The transition control word may be used to transition between various aspects of the operating modes, including different frequencies or resolutions, control systems, power levels, and more.

Abstract: A battery management system, may include an input configured to couple to a power supply, an output configured to couple to a battery, and battery management circuitry coupled between the power supply and the battery and configured to deliver electrical energy to the output at a significantly higher peak-to-average power ratio than receipt of electrical energy to the input.

Abstract: In accordance with embodiments of the present disclosure, a system may include a main integrated circuit (IC) comprising current measurement circuitry, an auxiliary current sense resistor coupled to the main IC, and an auxiliary pair of Kelvin sense resistors coupled between the auxiliary current sense resistor and the current measurement circuitry. The main IC may further comprise current injection circuitry configured to inject a known sink current which is split between a main current in a first path and an auxiliary current in a second path comprising the auxiliary current sense resistor.

Abstract: A cascaded switched power converter provides a wide voltage conversion ratio and improved efficiency ins systems such as power supplies and amplifiers. A switched-capacitor charge pump circuit is operated by one or more first clock signals and is coupled in cascade with an inductor-based power supply circuit according to one or more second clock signals. A control circuit that generates clock signals so that the one or more second clock signals have a phase offset with respect to the one or more first clock signals that is set to adjust a conversion ratio of the cascaded combination of the switched-capacitor charge pump circuit and the inductor-based power supply circuit. The inductor of the inductor-based power supply circuit may be an inductive load, such as a speaker, and the phase offset may be modulated according to an audio signal to provide audio amplification.

Abstract: This application relates to methods and apparatus for switching drivers. The switching driver has first and second switches for selectively connecting an output node to first and second switching voltages respectively to generate a first output voltage. A compensator is configured to receive a first monitor signal indicative of a sum of the first and second switching voltages and a second monitor signal indicative of a difference between the first and second switching voltages and to apply compensation to the input signal based on the first and second monitor signals so as to compensate for variations in the first and second switching voltages from defined nominal values of the first and second switching voltages. A modulator controls a duty cycle of the first and second switches based on the input signal after said compensation has been applied.

Abstract: Methods and systems for determining clock signals for audio processing using different operating modes are provided. In one aspect, a transition control word is determined to transition from a first control word for a first operating mode to a second control word for the second operating mode. The transition control word may be used to process the received audio signal while transitioning between the operating modes. After the transition, the second control word may be used to process the received audio signal using the second operating mode. The transition control word may be used to transition between various aspects of the operating modes, including different frequencies or resolutions, control systems, power levels, and more.

Abstract: A circuit for powering a battery monitor in devices powered by a multi-cell battery, provides efficient use of energy in standby operating modes of battery-powered devices. The circuit includes a switched-capacitor network having at least two capacitors and at least two corresponding first switches. The capacitors have first terminals intermittently coupled in alternation to first terminals of corresponding cells or groups of cells of the multi-cell battery and second terminals of the corresponding cells or groups of cells of the multi-cell battery by the first switches according to a first clock signal. The switched-capacitor network also includes at least one second switch that intermittently couples second terminals of the at least two capacitors to an output node according to the first clock signal. The output node is configured to supply power to the battery monitor. The circuit also includes a clocking circuit for generating the first clock signal.

Abstract: Pulse width modulation (PWM) driver circuitry comprising: a loop filter configured to receive an analog input signal and to output a digital loop filter output signal based on the analog input signal and an analog feedback signal; and a PWM modulator configured to receive a digital signal based on the digital loop filter output signal and to output a PWM signal, wherein the PWM driver circuitry further comprises a feedback path coupled to an output of the PWM driver circuitry for the analog feedback signal.

Abstract: A system for estimating parameters of an electromagnetic load may include an input for receiving an input excitation signal to the electromagnetic load, a broadband content estimator that identifies at least one portion of the input excitation signal having broadband content, and a parameter estimator that uses the at least one portion of the input excitation signal to estimate and output one or more parameters of the electromagnetic load.

Abstract: This application relates to voltage regulators and, particular, to low-dropout regulators (LDOs). The regulator (300) has an output stage (102) which receives an input voltage (Vin) and outputs an output voltage (Vout) and which includes at least one transistor (103) as an output device configured to pass an output current to the output, based on a drive voltage (V1). A differential amplifier (101) is configured to receive a feedback signal derived from the output voltage and also a reference voltage (REF) to generate an amplifier output to control the drive voltage (V1) to minimise any difference between the feedback signal and the reference voltage. A controller (301) is operable to selectively reconfigure the output stage to provide a change in output current in response to a load activity signal (ACT), which is indicative of a change in load activity that results in a change in load current demand for a load connected, in use, to the output.

Abstract: A non-transitory computer readable medium may have stored thereon data encoding a waveform signal for playback, wherein the waveform signal is generated by implementing a discrete time model of a physical electromagnetic load that emulates a virtual electromagnetic load and modifying a raw waveform signal to generate a waveform signal for driving the physical electromagnetic load by modifying the virtual electromagnetic load to have a desired characteristic and applying the discrete time model to the raw waveform signal to generate the waveform signal for driving the physical electromagnetic load.

Abstract: Accurate operation of a current monitor is provided by injecting a bias voltage to a maintain de-selected sense amplifier input in an active state. An electronic system includes an output stage to supply a load current and includes two push-pull output drivers having sense resistors supplying a first and a second sense voltage. An included mode control circuit selects between a first and a second operating mode and selects a polarity of the current. An included current monitor receives the sense voltages and has a control input coupled to the mode selection control circuit. The current monitor provides an output that is dependent on both sense voltages in the first operating mode and is indicative of one of the sense voltages selected according to the selected polarity in the second operating mode. The bias voltage is injected into an unselected sense inputs to maintain active operation of the sense amplifier.

Abstract: Amplifier circuits provide operation with low-distortion zero crossings outside of a unipolar power supply voltage range. The amplifiers include multiple driver circuits and a control circuit. The control circuit selects between actively operating selected ones of the multiple driver circuits or all of the multiple driver circuits, according to an input signal to be reproduced by one or more of the multiple amplifier driver circuits. The control circuit determines a splice point at which the control circuit selects between actively operating selected ones of the multiple driver circuits or all of the multiple driver circuits.

Abstract: A system may include amplifier circuitry configured to drive an electromagnetic load with a driving signal and a processing system communicatively coupled to the electromagnetic load and configured to compensate for current-sensing error of the processing system caused by feedback circuitry of the amplifier circuitry.

Abstract: A driver apparatus for driving a load with a differential drive signal is described. For a level of input signal within a first range, a first switching driver modulates the voltage at a first output node with a first modulation index by switchably connecting at least one flying capacitor to the first output node, whilst a second switching driver modulates the voltage at a second output node with a second modulation index by controlling switching between DC voltages that are maintained throughout a switching cycle of the driver apparatus. The first and second switching drivers are controlled so, for at least a first part of the first input range, a change in input signal level results in a change of the first controlled modulation index that has a different magnitude to any change in the second controlled modulation index, a constant modulation frequency of the differential drive signal is maintained.

Abstract: Circuitry for acoustic crosstalk cancellation between first and second acoustic signals, the circuitry comprising: crosstalk cancellation circuitry configured to: receive a first audio signal and, based on the received first audio signal, generate a first crosstalk cancellation signal; receive a second audio signal and, based on the received second audio signal, generate a second crosstalk cancellation signal; combine the first crosstalk cancellation signal with a signal indicative of the second audio signal to generate a first crosstalk cancellation circuitry output signal; and combine the second crosstalk cancellation signal with a signal indicative of the first audio signal to generate a second crosstalk cancellation circuitry output signal; and output stage circuitry configured to: receive the first crosstalk cancellation circuitry output signal and, based on the received first crosstalk cancellation circuitry, generate a first drive signal for driving a first speaker to generate the first acoustic signal

Abstract: Pre-conditioning circuitry for pre-conditioning a node of a circuit to support a change in operation of the circuit, wherein the circuit is operative to change a state of the node to effect the change in operation of the circuit, and wherein the pre-conditioning circuitry is configured to apply a voltage, current or charge directly to the node to reduce the magnitude of the change to the state of the node required by the circuit to achieve the change in operation of the circuit.

Abstract: A method may include, for a signal path comprising a passive antialiasing filter sampled by a switched-capacitor front-end, monitoring a change of a first impedance of a resistor of the passive antialiasing filter responsive to an environmental condition relative to a second impedance of a switched capacitor of the switched-capacitor front end and compensating the signal path for a change in gain of the signal path resulting from the change of the first impedance.