Abstract: An audio device includes an audio amplifier configured to receive an input signal and generate a differential output signal. A first signal combiner circuit is configured to generate a time-convolution signal of an analog current signal and an analog voltage signal. The analog current signal corresponds to a current at the differential output signal, and the analog voltage signal corresponds to a voltage across the differential output signal. A second signal combiner circuit is configured to subtract the generated time-convolution signal from the input signal.

Abstract: An audio device includes an audio amplifier configured to receive an input signal and generate a differential output signal. A first signal combiner circuit is configured to generate a time-convolution signal of an analog current signal and an analog voltage signal. The analog current signal corresponds to a current at the differential output signal, and the analog voltage signal corresponds to a voltage across the differential output signal. A second signal combiner circuit is configured to subtract the generated time-convolution signal from the input signal.

Abstract: An output stage configuration with four configurable input/output terminals and four switches is specified. Each switch has a first main terminal, a second main terminal and a control terminal, which receives a control signal for controlling the open or closed state of the switch. The output stage is included in a circuit together with a first control apparatus and a second control apparatus. When a control stage of the first control apparatus is connected to the output stage, a control stage of the second control apparatus is electrically disconnected from the output stage, and the output stage operates in a first operating state. When the control stage of the second control apparatus is connected to the output stage, the control stage of the first control apparatus is electrically disconnected from the output stage, the output stage then operating in a second operating state.

Abstract: A circuit may include an audio amplifier (314) configured to amplify an input signal (SAUDIO) to generate an output signal (SOUT+, SOUT?) suitable for driving a loud speaker (316). A first circuit (318) may be configured to generate a first analog signal (SI) based on a current level drawn by the loud speaker (316), and a second circuit (320) may be configured to generate a second analog signal (SV) based on a voltage supplied across the loud speaker (316). A third circuit (322, 312) may be configured to generate a third analog signal (RESIDUE) based on the difference between the first and second analog signals, and modify the input signal (SAUDIO) based on the third analog signal.

Abstract: The present invention relates to a method of protecting an inductive loudspeaker. The method comprises filtering the audio stream by applying a compensation filter to the audio stream, sending the filtered audio stream to the inductive loudspeaker, computing an estimation of a frequency response of the inductive loudspeaker and updating the compensation filter so as to attenuate a frequency corresponding to a resonant frequency in the estimated frequency response of the inductive loudspeaker.

Abstract: A circuit may include an audio amplifier (314) configured to amplify an input signal (SAUDIO) to generate an output signal (SOUT+, SOUT?) suitable for driving a loud speaker (316). A first circuit (318) may be configured to generate a first analog signal (SI) based on a current level drawn by the loud speaker (316), and a second circuit (320) may be configured to generate a second analog signal (SV) based on a voltage supplied across the loud speaker (316). A third circuit (322, 312) may be configured to generate a third analog signal (RESIDUE) based on the difference between the first and second analog signals, and modify the input signal (SAUDIO) based on the third analog signal.

Abstract: A circuit comprising: —an output stage according to the invention; —a first control apparatus comprising a control stage of the first control apparatus is connected to the output stage; and, —a second control apparatus comprising a control stage of the second control apparatus is connected to the output stage; wherein, —when the control stage of the first control apparatus is connected to the output stage, the control stage of the second control apparatus is electrically disconnected from the output stage, the output stage being configured to operate in a first operating state; and, —when the control stage of the second control apparatus is connected to the output stage, the control stage of the first control apparatus is electrically disconnected from the output stage, the output stage being configured to operate in a second operating state. The output stage and the use of the output stage are also claimed.

Abstract: The electronic device and a corresponding signal processing method disclosed herein reduces electromagnetic noise. To that end, the electronic device includes a delay line, an oscillator, and a modulator. The delay line generates a spread spectrum clock signal from an input clock signal, where a timing jitter and a period of jitter of the spread spectrum clock signal are controlled at each period of the spread spectrum clock signal based on a digital code. The oscillator uses the spread spectrum clock signal to generate a processing signal. The modulator modulates the processing signal as a function of an audio signal.

Abstract: There is described Audio driver circuit comprising a main, 1-bit digital-to-analog converter, adapted to receive a 1-bit oversampled digital audio signal. Thanks to an auxiliary digital-to-analog converter which converts into the analog domain a digital offset compensation value stored in e.g. an OTP memory register 34, and to a summing and filtering arrangement, it is possible to reduce the offset cancellation granularity in order to compensate for the offset of the main digital-to-analog converter in the output signal.

Abstract: There is described Audio driver circuit comprising a main, 1-bit digital-to-analog converter, adapted to receive a 1-bit oversampled digital audio signal. Thanks to an auxiliary digital-to-analog converter which converts into the analog domain a digital offset compensation value stored in e.g. an OTP memory register 34, and to a summing and filtering arrangement, it is possible to reduce the offset cancellation granularity in order to compensate for the offset of the main digital-to-analog converter in the output signal.

Abstract: The electronic device and a corresponding signal processing method disclosed herein reduces electromagnetic noise. To that end, the electronic device includes a delay line, an oscillator, and a modulator. The delay line generates a spread spectrum clock signal from an input clock signal, where a timing jitter and a period of jitter of the spread spectrum clock signal are controlled at each period of the spread spectrum clock signal based on a digital code. The oscillator uses the spread spectrum clock signal to generate a processing signal. The modulator modulates the processing signal as a function of an audio signal.

Abstract: The present invention relates to a method of protecting an inductive loudspeaker. The method comprises filtering the audio stream by applying a compensation filter to the audio stream, sending the filtered audio stream to the inductive loudspeaker, computing an estimation of a frequency response of the inductive loudspeaker and updating the compensation filter so as to attenuate a frequency corresponding to a resonant frequency in the estimated frequency response of the inductive loudspeaker.

Abstract: An integrated programmable gain amplifier circuit that receives at an input an analog signal, circuit including an operational amplifier and a gain setup network comprising resistive elements and selection elements, which may be controlled in order to setup the gain of the amplifier circuit. The gain setup network further includes capacitive elements, for defining, together with the resistive elements and the operational amplifier, an anti-aliasing filter of the active RC type.

Abstract: An integrated programmable gain amplifier circuit that receives at an input an analog signal, circuit including an operational amplifier and a gain setup network comprising resistive elements and selection elements, which may be controlled in order to setup the gain of the amplifier circuit. The gain setup network further includes capacitive elements, for defining, together with the resistive elements and the operational amplifier, an anti-aliasing filter of the active RC type.

Abstract: A single-ended or differential single-stage, or multi-stage sigma-delta analog-to-digital converter includes at least one switched-capacitor integrator comprising a switched-capacitor network receiving as input a signal to be sampled, and an amplifier coupled in cascade to the switched-capacitor network. A circuit is coupled to the amplifier for feeding an analog dither signal to a virtual ground of the amplifier.

Abstract: The circuit comprises a first ring oscillator comprising an odd number of inverting elements, a delay element and an output terminal; the delay element responds to a pulse at its input with a predetermined time delay with respect to a predetermined edge of the input pulse and substantially without time delay with respect to the other edge of the input pulse. With a view to avoiding start-up transients and generating pulses with a duty cycle that can be easily modified, the circuit comprises a second ring oscillator, having an output terminal connected to the output terminal of the first oscillator, and a bistable logic circuit having an output terminal connected to the common output of the first and the second oscillator. At least one of the inverting elements of the first oscillator and at least one of the inverting elements of the second oscillator form part of the bistable logic circuit.

Abstract: A circuit for selectively converting at least one analog signal into corresponding digital codes. The circuit includes a management block having a plurality of inputs, each adapted for receiving a respective request signal carrying a request to convert the at least one analog signal. The management block is adapted to assign a priority level to the request signals based upon the input where the request signals are received, and is further operative to select one of the request signals based upon the assigned priority level and output a conversion start-up signal corresponding to the selected request signal. The circuit has a conversion block for receiving east one analog signal input and is connected to the management block to receive the conversion start-up signal as input, and start up conversion of the at least one analog signal.

Abstract: A single-ended or differential single-stage, or multi-stage sigma-delta analog-to-digital converter includes at least one switched-capacitor integrator comprising a switched-capacitor network receiving as input a signal to be sampled, and an amplifier coupled in cascade to the switched-capacitor network. A circuit is coupled to the amplifier for feeding an analog dither signal to a virtual ground of the amplifier.

Abstract: The circuit comprises a first ring oscillator comprising an odd number of inverting elements, a delay element and an output terminal; the delay element responds to a pulse at its input with a predetermined time delay with respect to a predetermined edge of the input pulse and substantially without time delay with respect to the other edge of the input pulse. With a view to avoiding start-up transients and generating pulses with a duty cycle that can be easily modified, the circuit comprises a second ring oscillator, having an output terminal connected to the output terminal of the first oscillator, and a bistable logic circuit having an output terminal connected to the common output of the first and the second oscillator. At least one of the inverting elements of the first oscillator and at least one of the inverting elements of the second oscillator form part of the bistable logic circuit.

Abstract: A digital microphone device outputs a digital audio signal to a digital signal processing system. The digital microphone device includes an acoustic transducer for producing an analog voltage signal representative of an acoustic signal, and an integrated circuit including an input multiplexer. The input multiplexer has a first analog input coupled to an output of the acoustic transducer, and a second analog input to be connected to an output of a remote external analog microphone providing an analog voltage signal. A variable gain analog signal pre-amplifier is coupled to an output of the input multiplexer.