Abstract: The disclosure relates to microphone and other sensor assemblies having a transduction element and an integrated circuit. The integrated circuit includes a switched-capacitor delta-sigma analog-to-digital converter (ADC) including a first integrator stage having a switched-capacitor circuit and a first plurality of parallel amplifiers. A logic circuit coupled to the integrator circuit is configured to selectably disable a subset of enabled amplifiers of the first integrator stage during a first phase of operation and to re-enable the subset of disabled amplifiers during a second phase.

Abstract: Microphone devices and methods for manufacturing microphone devices that include a substrate having a first surface and a second surface, a cover secured to the first surface of the substrate to form an enclosed back volume, an application specific integrated circuit (ASIC) embedded between the first surface and the second surface of the substrate, a microelectromechanical systems (MEMS) transducer mounted on the first surface of the substrate, and an inductor mounted on the first surface of the substrate.

Abstract: The present disclosure relates to a balanced armature receiver (100) including a housing having a diaphragm comprising a movable paddle (116) disposed in the housing and separating the housing into a back volume (112) and a front volume (110) defined partly by space between a ceiling of the housing and the diaphragm, wherein the paddle is oriented non-parallel to the ceiling. A sound port (142) in the housing acoustically couples the front volume to an exterior of the housing, wherein the sound port is located on an end wall between the diaphragm and the ceiling. A motor disposed in the back volume includes a coil magnetically coupled to an armature having an end portion movably disposed between magnets retained by a yoke and coupled to the paddle.

Abstract: The disclosure relates to a MEMS sensor and an assembly including the MEMS sensor and an electrical circuit disposed in an assembly housing. The sensor includes a suspended structure (148) having a top diaphragm (118), a central electrode (120) and a bottom diaphragm (122) connected by a pillar portion (134). A peripheral portion of the suspended structure is coupled to a support structure (114), forming a low pressure cavity (130). The MEMS sensor includes a top electrode (136) disposed between the top diaphragm and the central electrode and a bottom electrode (138) disposed between the bottom diaphragm and central electrode each coupled to the support structure, wherein in the event of a sound pressure condition, the suspended structures moves up or down together, while the top electrode and the bottom electrode remain substantially stationary.

Abstract: This disclosure provides methods, systems, and apparatuses, for a microphone circuit. In particular, the circuit includes transducer that can sense pressure changes and generate an electrical signal having frequency components in a first frequency range and in a second frequency range higher than the first frequency range. The circuit includes a feedback circuitry that can attenuate frequency components in the first frequency range in the electrical signal and, from it, generate an audio signal. A feedback path circuit includes a low pass filter having a cut-off frequency within the first frequency range, and filters the audio signal to generate a low pass filter signal that includes frequency components in the first frequency range. The low pass filter signal can be used to generate a low frequency pressure signal that corresponds to low frequency pressure changes sensed by the transducer.

Abstract: The present disclosure relates generally to digital microphone and other sensor assemblies including a transducer, a delta-sigma analog-to-digital converter (ADC), a dynamic element matching (DELM) entity configured to compensate for nonlinearity resulting from variation among digital-to-analog conversion (DAC) elements of the ADC, and a control circuit configured to enable and disable the DELM based on a magnitude of a digital signal generated by the ADC.

Abstract: A MEMS can include a substrate including a first side and a second side on an opposite side of the substrate from the first side. The MEMS device can include an aperture running through the substrate from the first side to the second side. The substrate can have an edge surrounding the aperture on the first side. The MEMS device can include a diaphragm located over the aperture on the first side. The MEMS device can include a support structure that extends at least partially across the aperture from the edge.

Abstract: A microphone device includes a substrate having a first surface, a wall disposed on the first surface, a microelectromechanical systems (MEMS) transducer, and an integrated circuit. Both the MEMS transducer and the integrated circuit are mounted on the first surface of the wall. The wall separates the MEMS transducer from the integrated circuit and acoustically isolates the MEMS transducer from the integrated circuit. The microphone device additionally includes a first set of wires extending through the wall and electrically connecting the MEMS transducer to the integrated circuit. The microphone device further includes a second set of wires electrically connecting the integrated circuit to a conductor on the substrate.

Abstract: A microelectromechanical system (MEMS) transducer for integration in a microphone assembly is designed to produce heat-generated acoustic signals. The MEMS transducer generally comprises a substrate having an aperture, a transduction element located at least partially over the aperture and coupled to the substrate, electrical contacts coupled to the transduction element, and a resistor integrated with the substrate or the transduction element. The resistor is coupled to electrical contacts that are electrically isolated from the contacts of the MEMS transducer or transduction element. The transduction element includes an insulating material coupled to the substrate. The transduction element comprises a fixed electrode and a movable electrode located at least partially over the aperture of the substrate. The fixed electrode or the moving electrode is formed on the insulating material. The resistor can be formed on the insulating material or suspended from the insulating material.

Abstract: The present disclosure relates to a sensor assembly (100) comprising: a base (102) having a host-device interface (104), a lid (108) mounted on the base (102) to form a housing (110), the lid (108) having an insulative structural core (112) between an inner metal skin (114) and an outer metal skin (116); and a transduction element (118) disposed in the housing (112). Advantageously, the lid (108) of the sensor assembly (100) can help to minimize and reduce undesirable thermo-acoustic effects produced by external environmental conditions that may result in acoustic artifacts.

Abstract: A microphone assembly includes an acoustic transducer configured to generate an analog signal in response to pressure changes sensed by the acoustic transducer. The analog signal includes frequency components below a threshold frequency. The microphone assembly also includes an integrated circuit electrically coupled to the acoustic transducer and configured to determine a characteristic of frequency components below the threshold frequency, determine whether the characteristic of the frequency components corresponds to a fall event, and generate an output signal in response to a determination that the characteristic of the frequency components corresponds to the fall event. The microphone assembly also includes a housing having an external device interface with electrical contacts. The acoustic transducer and the integrated circuit are disposed within the housing. The integrated circuit is electrically coupled to contacts of the external device interface.

Abstract: The disclosure describes devices and methods for implementing impedance matching. The device may be implemented on an integrated circuit that includes a communication protocol interface circuit, a first signal output terminal, a first output driver circuit, and a controller. The first output driver circuit is coupled to the controller and has a corresponding plurality of parallel driver stages, each driver stage including a driver and a configurable resistance coupling an output of the driver to the first signal output terminal (e.g., first contact). The configurable resistances of the first output driver form a first series terminated resistance. The controller is configured to adjust the configurable resistances to adjust the first series terminated resistance.

Abstract: A system and method provides for multibeam keyword detection. A composite audio signal may include sound components. The system and method groups the sound components into subsets based on the angles of arrival of sound components. Keyword detectors evaluate each subset and determine whether a keyword is present.

Abstract: A wearable audio device, like a wireless earpiece, that generates a composite voice signal based on a low band signal and a high band signal is disclosed. The low band signal includes a component of the user's voice obtained from an acoustic vibration sensor that detect body conducted sounds and the high band signal includes a component of the user's voice obtained from a microphone that detects atmospheric sounds, wherein the low band signal is obtained predominately from the acoustic vibration sensor and the high band signal is obtained predominately from the microphone. The low and high band signals are based on one or more characteristics of the vibration sensor signal.

Abstract: A microphone device includes a base and a microelectromechanical system (MEMS) transducer and an integrated circuit (IC) disposed on the base. The microphone device also includes a cover mounted on the base and covering the MEMS transducer and the IC. The MEMS transducer includes a diaphragm attached to a surface of the substrate and a back plate mounted on the substrate and in a spaced apart relationship with the diaphragm. The diaphragm is attached to the surface of the substrate along at least a portion of a periphery of the diaphragm. The diaphragm can include a silicon nitride insulating layer, and a conductive layer, that faces a conductive layer of the back plate. The MEMS transducer can include a peripheral support structure that is disposed between at least a portion of the diaphragm and the substrate. The diaphragm can include one or more pressure equalizing apertures.

Abstract: A microphone assembly includes a transducer element and a processing circuit. The processing circuit includes an analog-to-digital converter (ADC) configured to receive, sample and quantize a microphone signal generated by the transducer element to generate a corresponding digital microphone signal. The processing circuit includes a feedback path including a digital loop filter configured to receive and filter the digital microphone signal to provide a first digital feedback signal and a digital-to-analog converter (DAC) configured to convert the first digital feedback signal into a corresponding analog feedback signal. The processing circuit additionally includes a summing node at the transducer output configured to combine the microphone signal and the analog feedback signal.

Abstract: An MEMS acoustic transducer includes a substrate having an opening formed therein, a diaphragm comprising a slotted insulative layer, and a first conductive layer. The slotted insulative layer is attached around a periphery thereof to the substrate and over the opening, and the first conductive layer is disposed on a first surface of the slotted insulative layer. A backplate is separated from the diaphragm and disposed on a side of the diaphragm opposite the substrate.

Abstract: An acoustic transducer for generating electrical signals in response to acoustic signals includes a transducer substrate, a back plate, and a diaphragm assembly. The diaphragm assembly includes a first diaphragm and a second diaphragm coupled thereto. The second diaphragm is positioned closer to the back plate than the first diaphragm. The second diaphragm includes a plurality of diaphragm apertures configured to allow air to pass through the second diaphragm. Each of the back plate and the first diaphragm are coupled to the transducer substrate at their periphery. In an embodiment, the transducer includes a post coupled to the first diaphragm and the second diaphragm, the post configured to prevent movement of the second diaphragm relative to the first diaphragm in a direction substantially perpendicular to the second diaphragm.

Abstract: Systems and methods for improved acoustic echo cancellation are provided. In various embodiments, a microphone located in the loudspeaker enclosure provides a first signal that is used to estimate the loudspeaker displacement which is proportional to the sound pressure level (SPL) inside the enclosure. A second signal is then derived by mapping the displacement to the loudspeaker's force factor (Bl(x)) and then modulating this by a measured current to a voice coil inside the speaker to provide an estimate of the force acting on the moving mass of the loudspeaker. The first signal is highly correlated with the echo signal for low frequencies and the second signal is highly correlated with the echo signal for high frequencies. The two signals are then combined to provide a single improved AEC reference signal.

Abstract: A microphone assembly includes an acoustic filter with a first highpass cut-off frequency. The microphone assembly additionally includes a forward signal path and a feedback signal path. The forward signal path is configured to amplify or buffer an electrical signal generated by a transducer in response to sound and to convert the electrical signal to a digital signal. The feedback signal path is configured to generate a digital control signal based on the digital signal and to generate and output a sequence of variable current pulses based on the digital control signal. The variable current pulses suppress frequencies of the electrical signal below a second highpass cut-off frequency, higher than the first highpass cut-off frequency.