A switching amplifier includes: a driver circuit with differential inputs and differential outputs; and a fault detection circuit coupled to the differential outputs. The fault detection circuit includes: a power supply input; and a sense circuit coupled to the differential outputs. The sense circuit includes: a first resistor between the power supply input and a positive output of the differential outputs; a second resistor between the positive output and ground; a third resistor between the power supply input and a negative output of the differential outputs; and a fourth resistor between the negative output and ground. The fault detection circuit also includes an analyzer circuit coupled to the sense circuit and configured to determine a fault location relative to the differential outputs based on an output of the sense circuit.

A switching amplifier includes: a driver circuit with differential inputs and differential outputs; and a fault detection circuit coupled to the differential outputs. The fault detection circuit includes: a power supply input; and a sense circuit coupled to the differential outputs. The sense circuit includes: a first resistor between the power supply input and a positive output of the differential outputs; a second resistor between the positive output and ground; a third resistor between the power supply input and a negative output of the differential outputs; and a fourth resistor between the negative output and ground. The fault detection circuit also includes an analyzer circuit coupled to the sense circuit and configured to determine a fault location relative to the differential outputs based on an output of the sense circuit.

An audio amplifier employs an idle mode to reduce power consumption and improve efficiency of the amplifier. The audio amplifier comprises a modulator configured to receive an analog input signal. The modulator is operable to convert the analog input signal to differential first and second quantized signals, each having a common mode duty cycle. The modulator causes the common mode duty cycle of each of the first and second quantized signals to be shifted when the level of the analog input signal is below a threshold level so that the common mode duty cycle is one of greater than or less than fifty percent (50%). The amplifier further includes a power stage that receives the first and second quantized signals and generates corresponding first and second output signals configured to drive a load, wherein the first and second output signals switched between a supply voltage and a second voltage based on the respective first and second quantized signals.

An audio amplifier employs an idle mode to reduce power consumption and improve efficiency of the amplifier. The audio amplifier comprises a modulator configured to receive an analog input signal. The modulator is operable to convert the analog input signal to differential first and second quantized signals, each having a common mode duty cycle. The modulator causes the common mode duty cycle of each of the first and second quantized signals to be shifted when the level of the analog input signal is below a threshold level so that the common mode duty cycle is one of greater than or less than fifty percent (50%). The amplifier further includes a power stage that receives the first and second quantized signals and generates corresponding first and second output signals configured to drive a load, wherein the first and second output signals switched between a supply voltage and a second voltage based on the respective first and second quantized signals.

A sense amplifier circuit comprising a first-, second-, third- and fourth-amplification-blocks, each amplification-block comprising: an amplification-block-transistor comprising and an amplification-block-resistor. The amplification-block-transistor includes: a first-conduction-channel-terminal, a second-conduction-channel-terminal that is connected to an amplification-block-output-node, and a control-terminal that is connected to an amplification-block-control-node. The sense amplifier circuit also comprises: an amplification-block-resistor connected in series between an amplification-block-input-node and the first-conduction-channel-terminal; a first-bias-voltage-source connected to the amplification-block-control-nodes of the first- and third-amplification-blocks, a second-bias-voltage-source connected to the amplification-block-control-nodes of the second- and fourth-amplification-blocks. The sense amplifier circuit also comprises: a first-common-mode-voltage-resistor connected in series between a first-sensed-output-terminal and a common-mode-voltage-node; and a second-common-mode-voltage-resistor connected in series between a second- sensed-output-terminal and the common-mode-voltage-node.

An audio amplifier that implements current mode control without the use of an explicit or separate current mode sensor is disclosed. The audio amplifier may include a pair of feedback loops that provide current from a node located before an inductor of an output filter and current from a node located after the inductor of the output filter to an integrator circuit. The integrator circuit may be formed from existing circuitry of the audio amplifier controller. Thus, current mode control can be implemented without a separate current mode sensor.

Provided are, among other things, systems, apparatuses methods and techniques for converting digital data to radio-frequency (RF) signals. One such apparatus includes a reactive-impedance network within which the levels of multiple binary waveforms are individually boosted, before being combined to produce a single, composite output signal.

Provided are, among other things, systems, apparatuses methods and techniques for converting digital data to radio-frequency (RF) signals. One such apparatus includes a reactive-impedance network within which the levels of multiple binary waveforms are individually boosted, before being combined to produce a single, composite output signal.

A system for driving a transducer having a plurality of coils, the system comprising: a modulator for outputting a digital output signal representative of a received analogue input signal at a modulator output; a clock controlled delay element for applying a delay to the digital output signal to generate a first delayed signal at a delay element output; wherein the modulator output is couplable to a first coil of the plurality of the coils of the transducer and the delay element output is couplable to a second coil of the plurality of coils of the transducer.

This application relates to an amplifier selectively operable in first or second modes. The first mode is a BTL mode with first and second output drivers (103p, 103n) both active to generate respective driving signals that vary with an input signal. The second mode is an SE mode, where the first output driver (103p) is active to generate a driving signal at and the output of the second driver (103n) is held constant. A controller (201) selectively controls the mode based on an indication of output signal amplitude. In the first mode, a ratio of magnitude of the two driving signals varies with the indication of output signal amplitude, i.e. the magnitudes of the two driving signals may vary so as to be not equal.