The application describes a switched driver (401) for outputting a drive signal at an output node (402) to drive a load such as a transducer. The driver receives respective high-side and low-side voltages (VinH, VinL) defining an input voltage at first and second input nodes and has connections for first and second capacitors (403H, 403L). A network of switching paths is configured such that each of the first and second capacitors can be selectively charged to the input voltage, the first input node can be selectively coupled to a first node (N1) by a path that include or bypass the first capacitor, and the second input node can be selectively coupled to a second node (N2) by a path that includes or bypasses the second capacitor. The output node (402) can be switched between two switching voltages at the first or second nodes. The driver is selectively operable in different operating modes, where the switching voltages are different in each of said modes.

An embodiment apparatus comprises a switching-type output power stage, a modulator circuit configured for carrying out a pulse-width modulation and converting an electrical input signal into an input signal pulsed between two electrical levels, having a mean value proportional to the amplitude of the input signal, and a circuit arrangement for controlling saturation of an output signal supplied by the switching-type output power stage. The circuit arrangement comprises a pulse-remodulator circuit, between the output of the modulator circuit and the input of the switching-type output power stage, that is configured for supplying, as a driving signal to the switching-type output power stage, a respective modulated signal pulsed between two electrical levels, measuring a pulse width as pulse time interval elapsing between two consecutive pulsed-signal edges of the pulsed input signal, and, if the measurement indicates that the latter is below a given minimum value, remodulating the pulsed input signal.

An embodiment apparatus comprises a switching-type output power stage, a modulator circuit configured for carrying out a pulse-width modulation and converting an electrical input signal into an input signal pulsed between two electrical levels, having a mean value proportional to the amplitude of the input signal, and a circuit arrangement for controlling saturation of an output signal supplied by the switching-type output power stage. The circuit arrangement comprises a pulse-remodulator circuit, between the output of the modulator circuit and the input of the switching-type output power stage, that is configured for supplying, as a driving signal to the switching-type output power stage, a respective modulated signal pulsed between two electrical levels, measuring a pulse width as pulse time interval elapsing between two consecutive pulsed-signal edges of the pulsed input signal, and, if the measurement indicates that the latter is below a given minimum value, remodulating the pulsed input signal.

A method may include measuring a physical quantity associated with a load driven by an amplifier, generating a windowing function having a variable length and based on a number of samples of the physical quantity to be processed, applying the windowing function to the physical quantity, performing a transform on the physical quantity as filtered by the windowing function, and determining a characteristic of the load based on the transform.

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.

An analog front end circuit with pulse width modulation current compensation comprises sensing a current condition and determining if the current condition is a positive or negative current condition. An appropriate control signal is determined according to the current condition and sent to turn on a positive current electronic switch if the current condition is a negative current condition or sent to turn on a negative current electronic switch if the current condition is a positive current condition. A positive compensation current flows to offset negative parasitic current when the positive current electronic switch is turned on and a negative compensation current flows to offset positive parasitic current when the negative current electronic switch is turned on. A master control unit utilizes pulse width modulation signals of various widths associated with various current conditions to be sent to turn on the positive electronic switch or the negative electronic switch.

To provide a lightweight and robust voltage amplifier and current amplifier for a test device for testing an electrical component, an amplifier is designed to output a test signal at a signal output between a positive output terminal and a negative output terminal. The amplifier includes a first half bridge and a second half bridge. A switching unit is provided, which is designed to connect the first half bridge and the second half bridge in parallel to the signal output in a first operating mode and to connect the first half bridge and the second half bridge in series with the signal output in a second operating mode.

Certain aspects of the present disclosure are generally directed to circuitry and techniques for voltage-to-current conversion. For example, certain aspects provide a circuit for signal amplification including a first amplifier; a first transistor, a gate of the first transistor being coupled to an output of the first amplifier and a drain of the first transistor being coupled to an output node of circuit; a first resistive element coupled between a first input node of the circuit and an input of the first amplifier; a second amplifier; a second transistor, a gate of the second transistor being coupled to an output of the second amplifier and a drain of the second transistor being coupled to the output node of circuit; and a second resistive element coupled between a second input node of the circuit and an input of the second amplifier.

A system is disclosed which allows for canceling high frequency rail to rail common mode swing at pulse-width modulation (PWM) frequency for a Class-D, H and G audio amplifier or a Linear Resonance Actuator (LRA) driver. This allows wide bandwidth current sensing without the need of external components, or large on-chip resistor-capacitor (RC) networks, facilitating integration of the sense resistor. In addition, the sense amplifier DC input common mode and audio band common mode swing is reduced, allowing a sense resistor high frequency common mode swing of a least twice the MOSFET gate break down voltages.