Abstract: Circuitry for determining an impedance of an electrochemical cell comprising at least one first electrode and a second electrode, the circuitry comprising: drive circuitry configured to apply a stimulus to the electrochemical cell, the stimulus having a stimulation frequency and a stimulation amplitude; and measurement circuitry configured to: sample an output of the electrochemical cell at a sampling frequency to generate an output signal; determine an output amplitude of output signal at one or more alias frequencies, the one or more alias frequency based on the stimulation frequency and the sampling frequency; and determine the impedance of the cell at the stimulation frequency based on the output amplitude at the one or more alias frequencies and the stimulation amplitude; and control circuitry configured to: control the sampling frequency and the stimulation frequency such that a Nyquist rate of the sampling frequency is greater than stimulation frequency.

Abstract: The present disclosure relates to circuitry for driving a load. The circuitry comprises driver circuitry configured to generate a drive signal, based on an input signal to the driver circuitry, for driving the load, and commutator circuitry for coupling the driver circuitry to the load. The commutator circuitry is configured to alternate between commutation states in response to a level of the drive signal meeting a drive signal threshold or in response to a level of the input signal meeting a first input signal threshold. The circuitry is configured to apply an offset to the input signal when the input signal is below a second input signal threshold so as to increase a minimum level of the drive signal above the drive signal threshold or to increase a minimum level of the input signal above the first input signal threshold.

Abstract: A method of cough detection in a headset, the method comprising: receiving a first signal from an external transducer of the headset; receiving a second signal from an in-ear transducer of the headset; and detecting a cough of a user of the headset based on the first and second signals.

Abstract: Circuitry for measuring a characteristic of an electrochemical cell, the circuitry comprising: a comparator having a first comparator input, a second comparator input and a comparator output; a feedback path between the comparator output and the second comparator input configured to provide a feedback signal to the second comparator input; and a loop filter configured to apply filtering to the feedback path to generate the feedback signal, wherein the loop filter comprises the electrochemical cell.

Abstract: Circuitry for determining an impedance of an electrochemical cell comprising at least one first electrode and a second electrode, the circuitry comprising: drive circuitry configured to apply a stimulus to the electrochemical cell; sense circuitry configured to measure a response of the electrochemical cell to the stimulus; and processing circuitry configured to: determine an estimated transfer function of the electrochemical cell based on the stimulus and the response; determine a score for the estimated transfer function; and adjust the stimulus or circuitry used to measure the response based on the score.

Abstract: Circuitry for measuring a characteristic of an electrochemical cell, the circuitry comprising: a comparator having a first comparator input, a second comparator input and a comparator output; a feedback path between the comparator output and the second comparator input configured to provide a feedback signal to the second comparator input; and a loop filter configured to apply filtering to the feedback path to generate the feedback signal, wherein the loop filter comprises the electrochemical cell.

Abstract: Apparatus for delivering power from a battery node of a battery to an output node, the output node coupled to an analyte monitoring device, the apparatus comprising: a slow charging path between the battery node and the output node; a fast charging path parallel to the slow charging path, the fast charging path switchably coupled between the battery node and the output node; and control circuitry configured to: selectively couple the fast charging path between the battery node and the output node to allow faster transfer of charge between the battery node and the output node than the slow charging path.

Abstract: This application relates to Class D amplifier circuits. A modulator controls a Class D output stage based on a modulator input signal (Dm) to generate an output signal (Vout) which is representative of an input signal (Din). An error block, which may comprise an ADC, generates an error signal (?) from the output signal and the input signal. In various embodiments the extent to which the error signal (?) contributes to the modulator input signal (Dm) is variable based on an indication of the amplitude of the input signal (Din). The error signal may be received at a first input of a signal selector block. The input signal may be received at a second input of the signal selector block. The signal selector block may be operable in first and second modes of operation, wherein in the first mode the modulator input signal is based at least in part on the error signal; and in the second mode the modulator input signal is based on the digital input signal and is independent of the error signal.

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: A method of detecting live speech comprises: receiving a signal containing speech; obtaining a first component of the received signal in a first frequency band, wherein the first frequency band includes audio frequencies; and obtaining a second component of the received signal in a second frequency band higher than the first frequency band. Then, modulation of the first component of the received signal is detected; modulation of the second component of the received signal is detected; and the modulation of the first component of the received signal and the modulation of the second component of the received signal are compared. It may then be determined that the speech may not be live speech, if the modulation of the first component of the received signal differs from the modulation of the second component of the received 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: The present disclosure relates to circuitry for driving a piezoelectric transducer based on an input signal. The circuitry comprises: primary driver circuitry configured to receive the input signal and to output a primary driving signal to the piezoelectric transducer based on the input signal; and secondary driver circuitry configured to receive an error signal indicative of an error between the input signal and the primary driving signal and to output a secondary driving signal to the piezoelectric transducer based on the error signal, wherein the primary driver circuitry and the secondary driver circuitry both comprise switching converter circuitry.

Abstract: A method of cough detection in a headset, the method comprising: receiving a first signal from an external transducer of the headset; receiving a second signal from an in-ear transducer of the headset; and detecting a cough of a user of the headset based on the first and second signals.

Abstract: A method of detecting live speech comprises: receiving a signal containing speech; obtaining a first component of the received signal in a first frequency band, wherein the first frequency band includes audio frequencies; and obtaining a second component of the received signal in a second frequency band higher than the first frequency band. Then, modulation of the first component of the received signal is detected; modulation of the second component of the received signal is detected; and the modulation of the first component of the received signal and the modulation of the second component of the received signal are compared. It may then be determined that the speech may not be live speech, if the modulation of the first component of the received signal differs from the modulation of the second component of the received signal.

Abstract: The present disclosure relates to Class D amplifier circuitry comprising a mode controller configured to dynamically adjust an operational switching mode of the Class D amplifier over a range between a Class AD mode and a Class BD mode.

Abstract: A method of cough detection in a headset, the method comprising: receiving a first signal from an external transducer of the headset; receiving a second signal from an in-ear transducer of the headset; and detecting a cough of a user of the headset based on the first and second signals.

Abstract: The present disclosure relates to circuitry for driving a piezoelectric transducer. The circuitry comprises amplifier circuitry configured to receive a drive signal and to output an output signal, based on the drive signal, to the piezoelectric transducer, a variable capacitor configured to be coupled in series with the piezoelectric transducer, and control circuitry. The control circuitry is configured to control a capacitance of the variable capacitor to compensate for hysteresis in the piezoelectric transducer and to control a gain of the amplifier circuitry to compensate for signal attenuation caused by the variable capacitor.

Abstract: Circuitry for measuring a characteristic of an electrochemical cell, the circuitry comprising: a comparator having a first comparator input, a second comparator input and a comparator output; a feedback path between the comparator output and the second comparator input configured to provide a feedback signal to the second comparator input; and a loop filter configured to apply filtering to the feedback path to generate the feedback signal, wherein the loop filter comprises the electrochemical cell.

Abstract: Balancing circuitry for balancing cells in first and second modules of a battery pack, wherein the first module comprises a first plurality of cells and the second module comprises a second plurality of cells, the balancing circuitry comprising: first cell balancing circuitry operative to balance the first plurality of cells of the first module; and second cell balancing circuitry operative to balance the second plurality of cells of the second module, wherein the second cell balancing circuitry is further operative to balance at least one cell of the first plurality of cells of the first module with at least one cell of the second plurality of cells of the second module.

Abstract: Balancing circuitry for balancing a set of N cells in a battery, the balancing circuitry comprising: a switch network configured to be coupled to the cells; and a set of capacitors coupled in parallel between the switch network and a common node, wherein the switch network is controllable such that: during a first phase of operation of the balancing circuitry the set of capacitors is coupled to a first subset comprising N?1 adjacent cells of the set of N cells; and during a second phase of operation the set of capacitors is coupled to a second subset comprising N?1 adjacent cells of the set of N cells, wherein the second subset is different from the first subset, and wherein, in use of the balancing circuitry, the common node is coupled intermittently, periodically or permanently to a reference voltage.