Abstract: This application relates to voltage regulators and, particular, to low-dropout regulators (LDOs). The regulator (300) has an output stage (102) which receives an input voltage (Vin) and outputs an output voltage (Vout) and which includes at least one transistor (103) as an output device configured to pass an output current to the output, based on a drive voltage (V1). A differential amplifier (101) is configured to receive a feedback signal derived from the output voltage and also a reference voltage (REF) to generate an amplifier output to control the drive voltage (V1) to minimise any difference between the feedback signal and the reference voltage. A controller (301) is operable to selectively reconfigure the output stage to provide a change in output current in response to a load activity signal (ACT), which is indicative of a change in load activity that results in a change in load current demand for a load connected, in use, to the output.

Abstract: This application relates to methods and apparatus for driving a transducer with switching drivers. A driver circuit has first and second switching drivers for driving the transducer in a bridge-tied-load configuration, each of the switching drivers having a respective output stage for controllably switching the respective driver output node between high and low switching voltages with a controlled duty cycle. Each of switching drivers is operable in a plurality of different driver modes, wherein the switching voltages are different in said different driver modes. A controller controls the driver mode of operation and the duty cycle of the switching drivers based on the input signal. The controller is configured to control the duty cycles of the first and second switching drivers within defined minimum and maximum limits of duty cycles; and to transition between driver modes of operation when the duty cycle of one of the switching drivers reaches a duty cycle limit.

Abstract: The disclosure relates in general to on-ear transition detection, and in particular to on-ear transition detection circuitry comprising: a monitoring unit operable to monitor a speaker current flowing through a speaker and/or a speaker voltage induced across the speaker, and to generate a monitor signal indicative of the speaker current and/or the speaker voltage; and an event detector operable to detect a qualifying disturbance in a sensor signal indicative of a qualifying pressure change incident on the speaker caused by the speaker transitioning from an on-ear state to an off-ear state or vice versa, wherein the sensor signal is, or is derived from, the monitor signal.

Abstract: An ambient-aware audio system reduces stationary noise and maintains dynamic environmental sound in a received input audio signal. The system includes a signal-to-noise ratio (SNR) estimator that estimates an a priori SNR and an a posteriori SNR, a gain function that uses the estimated SNRs as inputs to compute coefficients of a frequency domain noise reduction filter that uses the computed coefficients to filter a frame of the input audio signal to generate an output audio signal. The SNR estimator, gain function, and filter are configured to iterate over a plurality of frames of the input audio signal. The SNRs are estimated using the input audio signal and the output audio signal associated with one or more of the plurality of frames. The gain function is derived to minimize an expected value of differences between spectral amplitudes of the output audio signal and the input audio signal.

Abstract: Monitoring circuitry, comprising: a current monitoring unit operable to monitor a speaker current flowing through a speaker and generate a monitor signal indicative of that current; and a controller operable, based on a control signal, to control the current monitoring unit to control whether the monitor signal is generated and/or a property of the monitor signal.

Abstract: A method for screening a semiconductor device for production of excessive random telegraph sequence (RTS) noise includes measuring noise of the semiconductor device at a first temperature, changing the temperature of the semiconductor device to a second temperature different from the first temperature, measuring noise of the semiconductor device at the second temperature, extracting a characteristic of the measured noise at the first and second temperatures (e.g., standard deviation, HMM output, frequency domain spectrum of time domain noise measurement), making a comparison of the extracted first and second noise characteristics, and making a determination whether the semiconductor device produces excessive RTS noise based on whether the comparison is above a predetermined threshold. Two different bias conditions of the device may be employed rather than, or in addition to, the two different temperatures.

Abstract: A multi-path audio amplification system that provides an output drive signal to electromechanical output transducers provides improved undistorted headroom, reduced path switching noise, and/or improved frequency response performance. Multiple signal amplification paths receive an audio input signal and have corresponding multiple output stages that have differing output impedances. A mode selector selects an active one of the multiple signal amplification paths is selected to supply the output drive signal. Outputs of the multiple output stages are coupled to the electromechanical transducer to provide the output drive signal and at least one of the multiple signal amplification paths includes an equalization filter for filtering the audio input signal to compensate for phase or gain differences referenced from the input to the outputs of the multiple output stages due to interaction between the differing output impedances and an impedance of the electromechanical transducer.

Abstract: Embodiments described herein relate to methods and apparatuses for controlling an operation of a vibrational output system and/or an operation of an input sensor system, wherein the controller is for use in a device comprising the vibrational output system and the input sensor system. A controller comprises an input configured to receive an indication of activation or de-activation of an output of the vibrational output system; and an adjustment module configured to adjust the operation of the vibrational output system and/or the operation of the input sensor system based on the indication to reduce an interference expected to be caused by the output of the vibrational output system on the input sensory system.

Abstract: A method of randomizing inductor current in at least one of a plurality of parallel coupled peak/valley current-controlled power converters may include comparing the inductor current to a threshold to generate a comparison signal, delaying the comparison signal by a plurality of delay amounts to generate a plurality of delayed versions of the comparison signal, and randomly selecting one of the plurality of delayed versions of the comparison signal for controlling the inductor current during one or both of a charging state and a transfer state of the at least one of the plurality of parallel coupled peak/valley current-controlled power converters.

Abstract: Circuitry for detecting a capacitive load coupled between a first node and a second node, the circuitry comprising: drive circuitry for applying a first voltage to a first node over a first time period; processing circuitry configured to: measure a second voltage at the first node; and determine that the load is a capacitive load based on the second voltage.

Abstract: Wind noise reduction in microphone signals. A first microphone signal is obtained from a first omnidirectional microphone and, contemporaneously, a second microphone signal is obtained from a second omnidirectional microphone. The first and second microphone signals are mixed to produce an output signal. Mixing involves weighting the first and second microphone signals by respective first and second signal weights to produce respective first and second weighted microphone signals, and summing the first and second weighted microphone signals together to produce the output signal. The first and second signal weights are calculated to minimize the power of the output signal.

Abstract: A baseline unit for use in a sensor system, the sensor system comprising N force sensors which output N sensor signals, respectively, where N?2, the baseline unit configured to: monitor measures of gradients of the respective sensor signals; and, in dependence upon the measures of the gradients, control a stored baseline setting to control how a baseline signal for at least one of said sensor signals is calculated using a baseline-calculation method, the baseline-calculation method configured by the currently-stored baseline setting.

Abstract: An integrated circuit may include an output for providing an output signal to a transducer including both a source audio signal for playback to a listener and an anti-noise signal for countering the effect of ambient audio sounds in an acoustic output of the transducer, an error microphone input for receiving an error microphone signal indicative of the output of the transducer and the ambient audio sounds at the transducer, and a processing circuit.

Abstract: A method may include measuring an electrical parameter of an electromagnetic load having a moving mass during the absence of a driving signal actively driving the electromagnetic load, measuring a mechanical parameter of mechanical motion of a host device comprising the electromagnetic load, correlating a relationship between the mechanical parameter and the electrical parameter, and calibrating the electromagnetic load across a plurality of mechanical motion conditions based on the relationship.

Abstract: Embodiments described herein relate to methods and apparatuses for configuring a plurality of virtual buttons on a device. For example, each of the plurality of virtual buttons may be activated or deactivated based on a mode of operation of the device. By activating and deactivating different combinations of the plurality of virtual buttons depending on the mode of operation of the device, the inadvertent engagement of virtual buttons which would otherwise not be used in that mode of operation may be avoided.

Abstract: A system may include a power converter configured to receive an input voltage and generate an output voltage and a controller configured to control operation of the power converter based on a comparison of a current associated with the power converter to a threshold current and control the threshold current as a function of the input voltage.

Abstract: A method, comprising: obtaining one or more accelerometer signals derived from an accelerometer; and determining one or more parameters of wind at the accelerometer based on the one or more accelerometer signals.

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 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: The present disclosure relates to circuitry comprising: digital circuitry configured to generate a digital output signal; and monitoring circuitry configured to monitor a supply voltage to the digital circuitry and to output a control signal for controlling operation of the digital circuitry, wherein the control signal is based on the supply voltage.