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: 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: 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: 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: A microelectromechanical system (MEMS) device includes at least one substrate, a lid, a MEMS component, a sensor, and a power supply. The lid is coupled to the substrate so that the substrate and the lid cooperatively define an interior cavity. The MEMS component is disposed within the interior cavity. The sensor is disposed within the interior cavity and is arranged to detect a parameter of the interior cavity. The power supply provides current to the sensor. The power supply is configured to control current during a ramp-up transition of the current and a ramp-down transition of the current such that the ramp-up transition and the ramp-down transition have attenuated high-frequency components.

Abstract: Systems and apparatuses for a microelectromechanical system (MEMS) device. The MEMS device includes a housing, a transducer, and a sensor. The housing includes a substrate defining a port and a cover. The substrate and the cover cooperatively form an internal cavity. The port fluidly couples the internal cavity to an external environment. The transducer is disposed within the internal cavity and positioned to receive acoustic energy through the port. The transducer is configured to convert the acoustic energy into an electrical signal. The sensor is disposed within the internal cavity and positioned to receive a gas through the port. The sensor is configured to facilitate detecting at least one of an offensive odor, smoke, a volatile organic compound, carbon monoxide, carbon dioxide, a nitrogen oxide, methane, and ozone.

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: A microphone assembly includes an acoustic transducer and an audio signal electrical circuit configured to receive an output signal from the acoustic transducer. The output signal includes an audio signal component and a tracking signal component. The audio signal component is representative of an acoustic signal detected by the acoustic transducer and the tracking signal component is based on an input tracking signal applied to the acoustic transducer. The audio signal electrical circuit includes an analog to digital converter configured to convert the output signal into a digital signal, an extraction circuit configured to separate the tracking signal component and the audio signal component from the digital signal, an envelope estimation circuit configured to estimate a tracking signal envelope from the tracking signal component, and a signal correction circuit configured to reduce distortion in the audio signal component using the tracking signal envelope.

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: 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: 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: A transducer assembly comprises an acoustic transducer comprising a transducer substrate having a first aperture defined at a first location of the transducer substrate, an acoustic transducer diaphragm disposed on the transducer substrate over the first aperture, and an acoustic transducer back plate disposed on the transducer substrate axially spaced apart from the acoustic transducer diaphragm over the first aperture. The transducer assembly also includes a vibration transducer comprising the transducer substrate having a second aperture defined at a second location thereof, a vibration transducer diaphragm disposed on the transducer substrate over the second aperture, a vibration transducer back plate disposed on the transducer substrate axially spaced apart from the vibration transducer back plate over the second aperture, and an anchor coupled to one of the vibration transducer diaphragm or the vibration transducer back plate, the anchor disposed in the second aperture and suspended freely therewithin.

Abstract: A microphone assembly includes an acoustic transducer and an audio signal electrical circuit configured to receive an output signal from the acoustic transducer. The output signal includes an audio signal component and a tracking signal component. The audio signal component is representative of an acoustic signal detected by the acoustic transducer and the tracking signal component is based on an input tracking signal applied to the acoustic transducer. The audio signal electrical circuit includes an analog to digital converter configured to convert the output signal into a digital signal, an extraction circuit configured to separate the tracking signal component and the audio signal component from the digital signal, an envelope estimation circuit configured to estimate a tracking signal envelope from the tracking signal component, and a signal correction circuit configured to reduce distortion in the audio signal component using the tracking signal envelope.

Abstract: A microelectromechanical system (MEMS) device includes at least one substrate, a lid, a MEMS component, a sensor, and a power supply. The lid is coupled to the substrate so that the substrate and the lid cooperatively define an interior cavity. The MEMS component is disposed within the interior cavity. The sensor is disposed within the interior cavity and is arranged to detect a parameter of the interior cavity. The power supply provides current to the sensor. The power supply is configured to control current during a ramp-up transition of the current and a ramp-down transition of the current such that the ramp-up transition and the ramp-down transition have attenuated high-frequency components.

Abstract: A microphone device comprises a microphone die including a microphone motor, an acoustic integrated circuit structured to process signals produced by the microphone motor, and a sensor die stacked on top of the acoustic integrated circuit, wherein the sensor die comprises a pressure sensor. Another microphone comprises a microphone die including a microphone motor and an integrated circuit die. The integrated circuit die comprises an acoustic integrated circuit structured to process signals produced by the microphone motor, a pressure sensor, and a pressure integrated circuit structured to press signals produced by the pressure sensor.

Abstract: Systems and apparatuses for a microelectromechanical system (MEMS) device. The MEMS device includes a housing, a transducer, and a sensor. The housing includes a substrate defining a port and a cover. The substrate and the cover cooperatively form an internal cavity. The port fluidly couples the internal cavity to an external environment. The transducer is disposed within the internal cavity and positioned to receive acoustic energy through the port. The transducer is configured to convert the acoustic energy into an electrical signal. The sensor is disposed within the internal cavity and positioned to receive a gas through the port. The sensor is configured to facilitate detecting at least one of an offensive odor, smoke, a volatile organic compound, carbon monoxide, carbon dioxide, a nitrogen oxide, methane, and ozone.

Abstract: A microphone device comprises a microphone die including a microphone motor, an acoustic integrated circuit structured to process signals produced by the microphone motor, and a sensor die stacked on top of the acoustic integrated circuit, wherein the sensor die comprises a pressure sensor. Another microphone comprises a microphone die including a microphone motor and an integrated circuit die. The integrated circuit die comprises an acoustic integrated circuit structured to process signals produced by the microphone motor, a pressure sensor, and a pressure integrated circuit structured to press signals produced by the pressure sensor.

Abstract: A microphone device comprises a microphone die including a first microphone motor and a second microphone motor, an acoustic integrated circuit structured to process signals produced by the first microphone motor and the second microphone motor, and a sensor die stacked on top of the acoustic integrated circuit, wherein the sensor die comprises a pressure sensor. Another microphone comprises a microphone die including a first microphone motor and a second microphone motor and an integrated circuit die. The integrated circuit die comprises an acoustic integrated circuit structured to process signals produced by the first microphone motor and the second microphone motor, a pressure sensor, and a pressure integrated circuit structured to press signals produced by the pressure sensor.

Abstract: A microphone device comprises a microphone die including a first microphone motor and a second microphone motor, an acoustic integrated circuit structured to process signals produced by the first microphone motor and the second microphone motor, and a sensor die stacked on top of the acoustic integrated circuit, wherein the sensor die comprises a pressure sensor. Another microphone comprises a microphone die including a first microphone motor and a second microphone motor and an integrated circuit die. The integrated circuit die comprises an acoustic integrated circuit structured to process signals produced by the first microphone motor and the second microphone motor, a pressure sensor, and a pressure integrated circuit structured to press signals produced by the pressure sensor.

Abstract: A microphone system has a package with an interior, a MEMS microphone within the package interior and forming a backvolume between it and the package interior, and a MEMS valve coupled with at least one input aperture in the package. The package defines at least one input aperture (e.g., the prior noted aperture) for receiving an acoustic signal, and the MEMS microphone is mechanically coupled to at least a portion of one input aperture. The valve has a valve opening generally circumscribed by a valve seat. The valve is considered as having an open mode for permitting acoustic signal access into the package interior through the valve opening, and a closed mode for substantially preventing acoustic signal access into the package interior through the valve opening. The valve has a movable member configured to contact the valve seat when in the closed mode. This movable member is configured to move between the open mode and the closed mode in a direction that is generally perpendicular to the valve seat.