Abstract: A proportional to absolute temperature (PTAT) circuit is provided. By judiciously combining circuit elements into two or more cell it is possible to effectively dump bias current into impedance resistive element of a first cell from other cells of the circuit. As a result the circuit as a whole can operate with smaller resistive elements and therefore occupy less area when implemented in silicon. It is also possible to reduce the supply current that is required for providing specific output currents or voltages.

Abstract: A transistor switch device is provided that exhibits relatively good voltage capability and relatively easy drive requirements to turn the device on and off. This can reduce transient drive current flows that may perturb other components.

Abstract: Many processes for audio signal processing can benefit from voice activity detection, which aims to detect the presence of speech as opposed to silence or noise. The present disclosure describes, among other things, leveraging energy-based features of voice and insights on first and second formant frequencies of vowels to provide a low-complexity and low-power voice activity detector. A pair of two channels is provided whereby each channel is configured to detect voice activity in respective frequency bands of interest. Simultaneous activity detected in both channels can be a sufficient condition for determining that voice is present. More channels or pairs of channels can be used to detect different types of voices to improve detection and/or to detect voices present in different audio streams.

Abstract: A method of controlling sound reproduction may include applying an audio signal to a voice coil of the electrodynamic loudspeaker to produce sound, detecting one of an impedance and admittance of the loudspeaker across a predetermined audio frequency range based on a detected voice coil current and voice coil voltage and determining a fundamental resonance frequency of the loudspeaker based on the detected impedance or admittance. The fundamental resonance frequency of the loudspeaker may be compared with a nominal fundamental resonance frequency of the loudspeaker representing a nominal acoustic operating condition of the loudspeaker. A change of operating condition of the loudspeaker may be detected based on a frequency deviation between the determined fundamental resonance frequency and a nominal fundamental resonance frequency of the loudspeaker. The level of the audio signal may be attenuated in response to the frequency deviation meets a predetermined frequency error criterion.

Abstract: Current measurement apparatus comprises a measurement arrangement and a signal source. The measurement arrangement is configured to measure a current signal drawn by a load. The signal source is operative to apply a reference input signal to the measurement arrangement whereby an output signal from the measurement arrangement comprises a load output signal corresponding to the load drawn current signal and a reference output signal corresponding to the reference input signal.

Abstract: An isolator device is provided comprising a body of first dielectric material between the first and second conductors, such as primary and secondary coils of a micro-transformer. A region of second dielectric material is provided between the body of first dielectric material and at least one of the first and second electrodes, wherein the second dielectric material has a higher relative permittivity than the first dielectric material. This provides enhances ability to withstand the Electric fields generated at the edge of a conductor. The body of the first dielectric can be tapered to provide stress relief to prevent the second dielectric material developing stress cracks.

Abstract: A voltage generator is provided which is reliable, self starting and only requires a few components. The voltage generator comprises a first stage that provides a current to a second stage. The first stage has a temperature coefficient of one sign, such as positive, and the second stage has an opposing temperature coefficient, e.g. negative. The responses are summed such that the overall temperature coefficient is reduced.

Abstract: A multiple input multiple output (MIMO) calibration device (360) for calibrating a phase relationship between at least two signals present on at least two radio frequency (RF) paths coupling a wireless communication unit and the MIMO calibration device (360) is described. The MIMO calibration device (360) is operably coupleable via at least two RF paths between a wireless communication unit and an antenna arrangement (219).

Abstract: An analog switch may be maintained reliably in an off state. The switch comprises: a P-type first transistor having a source, a drain and a gate, a N-type second transistor having a source, a drain and a gate, and a switch control circuit to drive the gates of the first and second transistors. The drain of the first transistor and the source of the second transistor are connected at a first node, and the source of the first transistor and the drain of the second transistor are connected at a second node. When the voltage at the first or second nodes falls outside of a supply voltage range of the switch control circuit, the switch control circuit is operable, in response to a signal to make the switch high impedance, by adjusting the gate voltages of the first transistor and the second transistor.

Abstract: An output stage of a buffer or an amplifier connected to a switched capacitive load can operate in two phases to perform precharging and fine settling. The precharging and fine settling phases can be synchronized to the switching phases of the switched capacitive load connected to the amplifier. During the precharging phase, the output stage can be disconnected from the prior stages of the amplifier, and the output node of the amplifier can be connected to the switched capacitive load to precharge the capacitive load with the voltage already stored in the output stage. During the fine settling phase, the output stage can be reconnected to the prior stages of the amplifier, and the amplifier nodes can settle and get ready for sampling, which can occur at the end of the fine settling phase.

Abstract: A device to determine a state of a battery is disclosed. One or more transistors provide a resistance between first and second nodes. The one or more transistors are configured to conduct a supply current from a battery between the first node and the second node. A measurement circuit measures the voltage generated between the first node and the second node. The measurement circuit further measures the supply voltage. A calculation circuit generates an estimate of the supply current based on the voltage measured between the first node and the second node and the resistance of the one or more transistors. The calculation circuit generates an estimate of the state of charge of the battery based on the measured supply voltage and the estimate of the supply current.

Abstract: A circuit and method to filter a signal is provided. The circuit includes a notch filter circuit to receive an input signal and first and second tuning signals and to provide an output signal. The notch filter circuit has an input-output frequency response that includes a stopband region. The stopband region has a center frequency and has an attenuation level that is based at least on a tuning signal. The tunable filter circuit further includes a tuning circuit operable in at least two modes to generate the tuning signal. The at least two modes includes a tuning mode and a filtering mode. The tuning circuit generates the tuning signal such that the attenuation level of the stopband region is greater in the filtering mode than in the tuning mode.

Abstract: Early effects are intrinsically present in bipolar junction transistors (BJTs). Described are examples of complimentary to absolute temperature (CTAT) and proportional to absolute temperature (PTAT) cells that reduce errors associated with the Early effects that would otherwise be present.

Abstract: A single-ended mixer having a mismatched, high termination impedance is disclosed. The termination impedance can be mismatched by at least one order of magnitude higher than the standard impedance of a given design environment, such as a 50 Ohm environment for a radio frequency (RF) circuit. The termination impedance can be provided in close physical proximity to the mixer core of the single-ended mixer to allow a suitable bandwidth of operation.

Abstract: The present disclosure relates to a method and apparatus for generating a voltage reference. More particularly the present disclosure relates to a methodology and circuitry configured to provide an output signal that combines a proportional to absolute temperature component with a complimentary to absolute temperature component to generate a stable output which is not temperature dependent.

Abstract: A monitoring circuit for monitoring the performance of a phase locked loop having a divider therein, the divider comprising at least a first counter, the monitoring circuit comprising at least one memory element for capturing a value of the first counter after a predetermined time from a system event in the operation of the phase locked loop, a variability calculator for comparing a value of the counter with a preceding value of the counter to calculate a variation, and a circuit responsive to the estimate of variation for outputting a status signal.

Abstract: An optical sensor module is disclosed. The optical sensor module can include a housing comprising an air cavity. An optical emitter die can be disposed in the air cavity of the housing. A top surface of the optical emitter die can face a first side of the housing, the optical emitter die configured to emit light towards the first side of the housing. An optical sensor die can be disposed in the air cavity of the housing adjacent the optical emitter die. The optical sensor die can be spaced from the optical emitter die by a lateral distance. A top surface of the optical sensor die can face the first side of the housing. There may be no septum between the optical sensor die and the optical emitter die that optically separates the optical sensor die and the optical emitter die.

Abstract: A dynamically tunable transconductor includes a voltage-to-current converter stage for generating a current signal based on a voltage signal; and a current scaling stage for scaling the current signal by a scaling factor to achieve a particular transconductance. Current scaling stage includes a coarse tune mechanism having an associated coarse tune step and a fine tune mechanism having an associated fine tune step, where the scaling factor is a ratio of the coarse tune step to the fine tune step. A delta-sigma modulator can implement the transconductor to generate loop filter coefficients by dynamically tuning the transconductance to achieve a particular resistance.

Abstract: A MEMS switch has a base formed from a substrate with a top surface and an insulator layer formed on at least a portion of the top surface. Bonding material secures a cap to the base to form an interior chamber. The cap effectively forms an exterior region of the base that is exterior to the interior chamber. The MEMS switch also has a movable member (in the interior chamber) having a member contact portion, an internal contact (also in the interior chamber), and an exterior contact at the exterior region of the base. The contact portion of the movable member is configured to alternatively contact the interior contact. A conductor at least partially within the insulator layer electrically connects the interior contact and the exterior contact. The conductor is spaced from and electrically isolated from the bonding material securing the cap to the base.

Abstract: In an isolation system, different analog to digital converters (“ADCs”) are provided on a first side of an isolation barrier. Outputs from the ADCs may be merged into a common data stream and communicated across the isolation barrier by a single isolation device. The ADCs may sample independent signals or may sample a common signal. When the ADCs sample a common signal, the system may monitor the input signal for fault conditions. During no fault operation, results of an analog-to-digital conversion may be communicated across an isolation barrier by an isolation device. During a fault condition, data representing the fault condition may replace the ADC data in communication across the isolation barrier. Fault conditions may be signaled by unique data patterns that can be distinguished from ADC data.