Abstract: This application relates to computing circuitry (200, 500, 600) for analogue computing. A plurality of current generators (201) are each configured to generate a defined current (ID1, ID2, . . . IDj) based on a respective input data value (D1, D2, . . . Dj). A memory array (202), having at least one set (204) of programmable-resistance memory cells (203), is arranged to receive the defined currents from each of the current generators at a respective signal line (206). Each set (204) of programmable-resistance memory cells (203) includes a memory cell associated with each signal line that, in use, can be connected between the relevant signal line and a reference voltage so as to generate a voltage on the signal line. An adder module (207) is coupled to each of the signal lines to generate a voltage at an output node (210) based on the sum of the voltages on each of the signal lines.

Abstract: Control circuitry for controlling a current through an inductor of a power converter, the control circuitry comprising: comparison circuitry configured to compare a measurement signal, indicative of a current through the inductor during a charging phase of the power converter, to a signal indicative of a target average current through the inductor for the charging phase and to output a comparison signal based on said comparison; detection circuitry configured to detect, based on the comparison signal, a crossing time indicative of a time at which the current through the inductor during the charging phase is equal to the target average current for the charging phase; and current control circuitry configured to control a current through the inductor during a subsequent charging phase based on the crossing time.

Abstract: A data acquisition system (DAS) for acquiring data from a Hall effect sensor includes one or more state variables, a multiplexer that periodically rotates a signal from the Hall effect sensor, and a controller that resets the one or more state variables in synchronization with rotation of the signal. The state variables may be digital states in a digital memory or voltages of capacitors the controller forces to a reset voltage. The state variables may be included in a noise-shaping SAR ADC, a delta-sigma ADC, a digital filter, an integrator, an analog filter, a VCO, an incremental ADC or an auxiliary ADC-assisted incremental ADC, or an auxiliary ADC of the DAS.

Abstract: Driver circuitry for driving an electromechanical load with a drive output signal, the driver circuitry comprising: a first control loop operable to control the drive output signal based on a drive input signal; and a second control loop operable to control the drive output signal based on a current flowing through and/or a voltage induced across the electromechanical load, wherein the second control loop is configured to have a lower latency than the first control loop, and to control the drive output signal to compensate for an impedance of the electromechanical load.

Abstract: A signal processing system may include a sensor readout channel configured to convert an electronic signal into a digital quantity. The sensor readout channel may include a first-order sigma-delta modulator having a modulator input and a modulator output, first outside chopping switches located at the modulator input, second outside chopping switches located at the modulator output, an auxiliary path having an analog-to-digital converter (ADC) having an auxiliary path input and an auxiliary path output, the auxiliary path input configured to receive as its input signal a signal output by a memory element of the first-order sigma-delta modulator, and a signal combiner configured to combine a modulator output signal generated by the first-order sigma-delta modulator with an auxiliary path output signal generated by the auxiliary path to generate a combined output signal.

Abstract: This application relates to methods and apparatus for driving a transducer with switching drivers where the switching driver has an output bridge stage for switching an output node between switching voltages and a modulator for controlling the duty cycle of the output bridge stage based on an input signal. The switching driver also includes a voltage controller for providing the switching voltages which is operable to provide different switching voltages in different driver modes. A controller is provided to control the driver mode of operation and the duty cycle of the switching driver based on the input signal, and the controller is configured to transition from a present driver mode to a new driver mode by controlling the voltage controller to provide the switching voltages for the new mode and controlling the modulator to vary the duty cycle of the output bridge stage. The change in duty cycle is controlled such that there is no substantial discontinuity in switching ripple due to the mode transition.

Abstract: A system for controlling a current in a power converter configured to generate an output voltage may include a control loop having a plurality of comparators, each comparator having a respective reference voltage to which the output voltage is compared, a digital controller configured to calculate one or more pre-seeded control parameters for the current, and an analog state machine configured to, based on outputs of the plurality of comparators, select control parameters for controlling the current. The control parameters may be selected from the pre-seeded control parameters, control parameters for controlling the current to have a magnitude of zero, and control parameters for controlling the current to have a maximum magnitude.

Abstract: This application relates to microphone authentication apparatus for verifying whether or not an audio signal originated at a microphone. The microphone authentication apparatus has a comparison block configured to receive a first signal indicative of one or more spectral parameters of at least part of an audio signal to be verified, and compare the one or more spectral parameters to one or more predetermined characteristic microphone parameters relating to a characteristic resonance associated with an acoustic port of a microphone. The first signal may be an audio signal and the microphone authentication apparatus may have a feature extract module for determining the spectral parameters. Based on the comparison determination block may whether the audio signal originated from a microphone and may send a verification signal to a voice biometric module.

Abstract: This application relates to methods and apparatus for transfer of data between a host device (400) and a peripheral device (300) via a USB Type-C connector (100; 304) of the host device. A data controller is described that has a path controller (309, 310; 706) for establishing signal paths between circuitry of the host device and contacts (101) of said USB Type-C connector. The path controller is operable in at least first and second modes. In the first mode the path controller establishes separate signal paths to each of at least first, second, third and fourth contacts (A6, A7, B6, B7) of the USB Type-C connector and a plurality of the established signal paths are for transfer of analogue audio data. In the second mode the path controller establishes a pair of signal paths to only a subset of said first to fourth contacts to provide a differential digital data path.

Abstract: A system may include a power source, a power converter having an input coupled to the power source and an output for supplying electrical energy to a load, and a control circuit for controlling operation of the power converter. The control circuit may include a first feedback control subsystem configured to monitor an output voltage present at the output of the power converter and regulate the output voltage at or about a predetermined regulated voltage level in a normal mode of operation of the power converter and a second feedback control subsystem configured to monitor an input voltage present between the power source and the input of the power converter and responsive to the input voltage decreasing below a predetermined minimum voltage level, causing the power converter to operate in a protection mode of operation in order to maintain the input voltage at or about the predetermined minimum voltage level.

Abstract: A switched mode amplifier system may include a switched mode amplifier having an amplifier input coupled to an output of an analog integrator and an amplifier output, include a feedback network coupled between the amplifier output and an input of the analog integrator, and a calibration system. The calibration system may be configured to force the input of the analog integrator to a fixed known input value, force the amplifier output to a fixed known duty cycle, measure an analog signal generated at the output of the analog integrator in response to forcing the input of the analog integrator to the fixed value, determine an offset of the switched mode amplifier system based on the analog signal, and correct for the offset.

Abstract: Circuitry for noise cancellation in a headset worn by a user, the circuitry comprising: an input for receiving one or more heartbeat signals representative of a heartbeat of the user; a processor for generating a heartbeat noise cancellation signal based on the one or more heartbeat signal, the heartbeat noise cancellation signal to cancel a noise associated with the heartbeat in the user's ear; an output for outputting the heartbeat noise cancellation signal to a transducer of the headset.

Abstract: In accordance with embodiments of the present disclosure, a method of driving a playback waveform to an electromagnetic actuator by a transducer driving system may include operating the transducer driving system in a first mode wherein the electromagnetic actuator is driven with the playback waveform in a closed loop to form a closed-loop voltage drive system that includes a negative impedance, operating the transducer driving system in a second mode wherein the electromechanical actuator is driven with the playback waveform in an open loop, and operating a mode switch for transitioning the transducer driving system to operate between the first mode and the second mode.

Abstract: Methods, apparatus and systems for biometric authentication based on an audio signal are provided. The audio signal comprises a representation of a voice signal of a user conducted via at least part of a user's skeleton. Further embodiments may relate to biometric authentication based upon a combination of a bone-conducted audio signal, or a bone-conducted voice biometric process, with an air-conducted voice signal.

Abstract: This application relates to methods and apparatus for computing, especially to circuitry for performing computing, at least partly, in the analogue domain. The circuitry (200) comprises a plurality of memory cells (201), each memory cell having first and second paths between an electrode (202) for receiving an input current and respective positive and negative electrodes (203) for outputting a differential-current output. Memristors (101) are located in the first and second paths. The memory cells are configured into sets (205) of memory cells, the memory cells of each said set being connected so as to provide a differential current set output that corresponds to a combination of the cell outputs of all of the memory cells of that set. For each set, at least some of the memory cells of that set are configured to receive a different input current to other memory cells of that set.

Abstract: A detected sound signal may comprise speech or non-verbal sounds, and many non-verbal sounds contain health information. If the speech, or a non-verbal sound containing health information, was produced by an enrolled user, data relating to the sound can be stored in a storage element. A system also comprises a data modification block, for obfuscating received data to provide an obfuscated version of the stored data. The system then has a first access mechanism, for controlling access to the stored data such that only an authorised user can obtain access to said stored data, and a second access mechanism, for controlling access to said stored data such the second access mechanism only provides access to the obfuscated version of the stored data.

Abstract: A system may include a Class-D stage comprising a first high-side switch coupled between a supply voltage and a first output terminal of the Class-D stage, a second high-side switch coupled between the supply voltage and a second output terminal of the Class-D stage, a first low-side switch coupled between a ground voltage and the first output terminal, and a second low-side switch coupled between the ground voltage and the second output terminal. The system may also include current sensing circuitry comprising a sense resistor, such that an output current through a load coupled between the first output terminal and the second output terminal causes a first sense voltage proportional to the output current across the sense resistor.

Abstract: A method for authenticating a user of an electronic device is disclosed. The method comprises: responsive to detection of a trigger event indicative of a user interaction with the electronic device, generating an audio probe signal to play through an audio transducer of the electronic device; receiving a first audio signal comprising a response of the user's ear to the audio probe signal; receiving a second audio signal comprising speech of the user; and applying an ear biometric algorithm to the first audio signal and a voice biometric algorithm to the second audio signal to authenticate the user as an authorised user.

Abstract: The present disclosure relates to a neural network system comprising: a data input configured to receive an input data signal and analog neural network circuitry having an input coupled with the data input. The analog neural network circuitry is operative to apply a weight to a signal received at its input to generate a weighted output signal. The neural network system further comprises compensation circuitry configured to apply a compensating term to the input data signal to compensate for error in the analog neural network circuitry.

Abstract: A host device configured to be wirelessly coupled to an accessory device, the host device comprising noise reduction circuitry, wherein, in use of the host device: a signal generated by a microphone of the accessory device in response to ambient noise is supplied to the noise reduction circuitry; the noise reduction circuitry applies a noise reduction transfer function to the signal supplied thereto to generate a noise cancellation signal; and the noise cancellation signal is supplied to at least one loudspeaker of the accessory device; and wherein the noise reduction transfer function applied by the noise reduction circuitry is user selectable or user adjustable.