Abstract: Acoustic transducers for generating electrical signals in response to acoustic signals are disclosed. In some embodiments, an acoustic transducer includes an at least partially evacuated hermetically sealed cavity defined in part by a first diaphragm. The acoustic transducer also includes a backplate disposed at least partially within the cavity. The cavity having a pressure lower than atmospheric pressure. The acoustic transducer further includes a pressure sensor coupled to the backplate and configured to sense the pressure in the cavity.

Abstract: The disclosure describes soft limiting electrical signals generated by a transducer before amplification, buffering or other signal conditioning in a microphone assembly, circuits and methods therefor. The soft limiting circuit includes a first circuit portion that limits a first portion of the electrical signal with reduced distortion when the first portion of the signal exceeds a threshold. A second circuit portion of the soft limiting circuit similarly limits a second portion of the electrical signal. In this way, overloading of an amplifier is avoided without excessive distortion.

Abstract: A microelectromechanical system (MEMS) motor includes a substrate, a backplate, and a diaphragm. The substrate has a first surface and a second surface. The second surface has a slot that extends at least partially into the substrate. A port extends through the substrate. The backplate is mounted to the first surface of the substrate, and the backplate covers at least a portion of the port. The diaphragm is between the backplate and the substrate. The diaphragm moves with respect to the backplate in response to acoustic energy that passes through the port.

Abstract: Sound-producing acoustic receivers are disclosed. The acoustic receiver includes a receiver housing with a first internal volume and a second internal volume, a first diaphragm separating the first internal volume into a first front volume and a first back volume such that the first front volume has a first sound outlet port, a second diaphragm separating the second internal volume into a second front volume and a second back volume such that the second front volume has a second sound outlet port, a motor disposed at least partially inside the housing such that the motor including an armature mechanically coupled to both the first diaphragm and the second diaphragm, an acoustic seal between the first front volume and the second back volume such that the acoustic seal accommodates the mechanical coupling of the armature to one of the first diaphragm or the second diaphragm.

Abstract: A MEMS vibration sensor die can include a substrate having a top portion, a mounting surface, and an aperture extending at least partially through the substrate. The die can include a first electrode coupled to the top portion of the substrate and positioned over the aperture. The die can include a second electrode disposed between the substrate and the first electrode. The second electrode can be spaced apart from the first electrode. The die can include a proof mass that can have a first portion coupled to the first electrode or the second electrode. The proof mass can have a second end opposite the first portion. The second end can be recessed within the aperture relative to the mounting surface of the substrate. The proof mass can be suspended freely within the aperture. The proof mass can move the first electrode or the second electrode from which it is suspended in response to vibration.

Abstract: This disclosure provides methods, systems, and apparatuses, for a microphone. In particular, the microphone includes a housing having an external device interface with a plurality of contacts including a data contact. An electro-acoustic transducer is configured to generate an electrical signal in response to sound. An electrical circuit is coupled to contacts of the interface, the electrical circuit including an ADC having an input coupled to an output of the conditioning circuit and configured to convert the electrical signal to audio data after conditioning. A controller is configured to communicate data, other than the audio data, via the data contact of the external device interface during a start-up transition period of the microphone assembly, wherein the controller is configured to communicate the audio data via the data contact of the external device interface only after the start-up transition period is complete.

Abstract: A microphone can include an adapter housing. The adapter housing can include an opening and an outer acoustic port. The microphone can include an internal microphone assembly disposed at least partially within the adapter housing. The internal microphone assembly can include an internal housing having an internal acoustic port. The internal microphone assembly can include a plurality of contacts disposed on the internal housing. The contacts can be accessible through the opening of the adapter housing. An interior of the internal housing can be acoustically coupled to the outer acoustic port via the internal acoustic port.

Abstract: A microphone assembly includes a substrate defining a port, a MEMS transducer, a guard ring, and a can. The MEMS transducer is coupled to the substrate such that the MEMS transducer is positioned over the port. The guard ring is coupled to the substrate and surrounds the MEMS transducer. The guard ring includes a plurality of edges that further includes a first edge and an opposing second edge. A portion of the first edge and a portion of the second edge have a reduced thickness relative to adjacent ones of the plurality of edges. The can is coupled to the guard ring such that the substrate and the can cooperatively define an interior cavity.

Abstract: A micro-electromechanical system (MEMS) transducer assembly includes a transducer including a condenser microphone, an integrated circuit electrically connected to the transducer to receive an output voltage from the transducer, wherein the integrated circuit comprises a test signal generator configured to induce a test acoustic response in the transducer, and an evaluation circuit configured to compare the test acoustic response to a baseline acoustic response to identify a fault in the transducer.

Abstract: The present disclosure relates to an integrated circuit comprising a transconductance amplifier which is connectable to a microelectromechanical systems (MEMS) transducer. The transconductance amplifier comprises a first input coupled to a first current conveyor and a second input coupled to a second current conveyor for converting a single-ended or differential transducer signal voltage into an intermediate signal current representative of the transducer signal voltage through a shared reference resistor. The transconductance amplifier further comprises first and second output circuits coupled to the shared reference resistor and being configured to convert the intermediate current signal into a corresponding differential output current signal through first and second output terminals for driving a load.

Abstract: A sensor signal processing circuit including a delta-sigma analog-to-digital converter (ADC) and a control circuit is disclosed. The circuit is configured to adaptively activate one or more segments of current elements for sequential sampling periods based on a digital signal input to a DAC, wherein less than N current elements are allocated to each segment, each current element in an active segment is enabled and either contributes to a feedback signal of the DAC or does not contribute to the feedback signal, and current elements not in an active segment are disabled. The circuit can be integrated with an acoustic or other sensor as part of a sensor assembly.

Abstract: A microphone assembly includes an acoustic transducer having a back plate and a diaphragm, such that a surface of the back plate includes a plurality of holes. At least a portion of the plurality of holes are arranged in a non-uniform pattern. The non-uniform pattern includes holes of varying sizes spaced apart from neighboring holes by varying distances. The microphone assembly further includes an audio signal electrical circuit configured to receive an acoustic signal from the acoustic transducer.

Abstract: The present disclosure relates to an integrated circuit connectable to a microelectromechanical system (MEMS) transducer. The MEMS transducer is configured to generate a transducer audio signal in response to sound. The integrated circuit comprises a digital scrambling circuit coupled to a data communication interface. The digital scrambling circuit is configured to convert a digital audio stream, representative of the transducer audio signal, into a corresponding scrambled data stream. The integrated circuit additionally comprises a data bus interface coupled to the digital scrambling circuit and configured to output the scrambled data stream.

Abstract: An acoustic receiver includes a cover made from an electrically non-conductive material configured to cover an open end of a housing portion of the acoustic receiver. The cover has an inner surface and an outer surface. A motor is disposed on the inner surface, while electrical contacts are disposed on the outer surface. The motor is connected to the electrical contacts on the outer surface. Various electrical components, such as integrated circuits and sensors, are disposed on the outer surface. In one embodiment, the cover is a printed circuit board.

Abstract: A system and method in an audio signal electrical circuit including a feedback loop with a digital filter coupled to a current digital to analog converter (IDAC) includes providing an output signal from the IDAC to analog elements of the audio signal electrical circuit, the output signal from the IDAC based upon a reference signal input to the IDAC when an output of the digital filter is not input to the IDAC. The system and method also include comparing an output signal of the audio signal electrical circuit to a reference, and calibrating the audio signal electrical circuit to correspond the output signal of the audio signal electrical circuit to the reference. Calibration of the audio signal electrical circuit enables more precise control of a cut-off frequency of a microphone signal when the output of the digital filter is input to the IDAC.

Abstract: A communication system and method is disclosed. The system and method provides for acoustic echo cancellation. For instance, a processor implements a non-linear loudspeaker model to approximate loudspeaker performance. Using the model, a cancellation signal may be generated to ameliorate cross-talk between a loudspeaker and microphone to diminish an echo.

Abstract: An acoustic transducer comprises a transducer substrate defining an aperture therein. A diaphragm is disposed on the transducer substrate. The diaphragm comprises a diaphragm inner portion disposed over the aperture such that an outer edge of the diaphragm inner portion is located radially inwards of a rim of the aperture, the diaphragm inner portion having a first stress. A diaphragm outer portion extends radially from the outer edge of the diaphragm inner portion to at least the rim of the aperture, the diaphragm outer portion having a second stress different from the first stress.

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 system method provides for multi-port wind noise protection. A sound may include a desired component such as speech and an undesired component such as wind. Multiple apertures on a housing receive the sound and conduct it to a microphone. The undesired component such as wind is uncorrelated at the apertures and mixes at the microphone, attenuating in amplitude while the desired component such as speech is correlated at the apertures. In this manner, the signal to noise ratio between the desired component and undesired component is improved at the microphone.

Abstract: A microelectromechanical system (MEMS) transducer includes a transducer substrate including an opening; a back plate including a plurality of protrusions oriented substantially perpendicular to the back plate; and a diaphragm between the transducer substrate and the back plate. The diaphragm includes a lead and a plurality of spring members. The lead is structured to suspend the diaphragm over the transducer substrate. The spring members are structured to separate the diaphragm from the transducer substrate and the back plate in the absence of a bias voltage.