In an embodiment a device includes a substrate including an upper substrate surface and a lower substrate surface and a membrane-layer suspended above the upper substrate surface, wherein the substrate includes a recess penetrating the substrate between the lower substrate surface and the upper substrate surface, wherein the membrane-layer spans the recess, wherein the recess includes an upper recess region, an intermediate recess region, and a lower recess region, wherein the upper recess region is a part of the recess in direct vicinity to the upper substrate surface, the intermediate recess region is a part of the recess directly below the upper recess region, and the lower recess region is a part of the recess other than the upper recess region and the intermediate recess region, and wherein a cross-sectional area of the upper recess region determined parallel to the upper substrate surface is larger than a respective cross-sectional area of the intermediate recess region.

In an embodiment a device includes a substrate including an upper substrate surface and a lower substrate surface and a membrane-layer suspended above the upper substrate surface, wherein the substrate includes a recess penetrating the substrate between the lower substrate surface and the upper substrate surface, wherein the membrane-layer spans the recess, wherein the recess includes an upper recess region, an intermediate recess region, and a lower recess region, wherein the upper recess region is a part of the recess in direct vicinity to the upper substrate surface, the intermediate recess region is a part of the recess directly below the upper recess region, and the lower recess region is a part of the recess other than the upper recess region and the intermediate recess region, and wherein a cross-sectional area of the upper recess region determined parallel to the upper substrate surface is larger than a respective cross-sectional area of the intermediate recess region.

Provided is a preamplifying circuit, including a first amplifier and a second amplifier sequentially connected in series, wherein an output end of the second amplifier is connected to a circuit output end, and an input end of the first amplifier is connected to a circuit input end. The preamplifying circuit further includes a positive feedback branch including a diode group and a third amplifier, wherein one end of the diode group is connected to the input end of the first amplifier. The positive feedback circuit can positively feed part of signals back to the other end of the diode group, so that voltage drops at two ends of the diode group can be reduced, and harmonic distortion caused by nonlinearity of the diode group is reduced. Thus, the sound quality detected by a microphone sensor is improved.

A MEMS sensor includes a through hole to allow communication with an external environment, such as to send or receive acoustic signals or to be exposed to the ambient environment. In addition to the information that is being measured, light energy may also enter the environment of the sensor via the through hole, causing short-term or long-term effects on measurements or system components. A light mitigating structure is formed on or attached to a lid of the MEMS die to absorb or selectively reflect the received light in a manner that limits effects on the measurements or interest and system components.

A MEMS sensor includes a through hole to allow communication with an external environment, such as to send or receive acoustic signals or to be exposed to the ambient environment. In addition to the information that is being measured, light energy may also enter the environment of the sensor via the through hole, causing short-term or long-term effects on measurements or system components. A light mitigating structure is formed on or attached to a lid of the MEMS die to absorb or selectively reflect the received light in a manner that limits effects on the measurements or interest and system components.

The present disclosure discloses a sensitive diaphragm comprising a diaphragm body, an edge region of the diaphragm body being provided with a rim structure, wherein the rim structure is in a non-closed annular shape, a non-closed region is located at a part not closed by the rim structure, and the non-closed region are integral and continuous with parts of the diaphragm body adjacent to the rim structure. According to the sensitive diaphragm of the present disclosure, the annular rim structure is separated by the non-closed region.

Protected microphone systems may include one or more dampeners, one or more cavities, or a combination thereof to minimize the vibration sensitivity of a microphone of the protected microphone systems. The dampeners, when present, may be constructed of a foam material or a thin metal material.

A MEMS transducer system has a transducer configured to convert a received signal into an output signal for forwarding by a transducer output port, and an integrated circuit having an IC input in communication with the transducer output port. The IC input is configured to receive an IC input signal produced as a function of the output signal. The system also has a dividing element coupled between the IC input and the transducer output port. The dividing element is configured to selectively attenuate one or more signals into the IC input to at least in part produce the IC input signal. Other implementations may couple a feedback loop to the ground of the transducer (similar to bootstrapping), or pick off voltages at specific portions of the transducer.

A MEMS transducer system has a transducer configured to convert a received signal into an output signal for forwarding by a transducer output port, and an integrated circuit having an IC input in communication with the transducer output port. The IC input is configured to receive an IC input signal produced as a function of the output signal. The system also has a dividing element coupled between the IC input and the transducer output port. The dividing element is configured to selectively attenuate one or more signals into the IC input to at least in part produce the IC input signal. Other implementations may couple a feedback loop to the ground of the transducer (similar to bootstrapping), or pick off voltages at specific portions of the transducer.

A piezoelectric microelectromechanical systems (MEMS) transducer that can operate as a microphone (e.g., contact microphone) or a speaker is presented herein. The piezoelectric MEMS transducer includes a substrate, a proof mass and folded displacement sensing structures. Each folded displacement sensing structure comprises a continuous beam, a first piezoelectric stress sensor coupled to a first portion of the continuous beam, and a second piezoelectric stress sensor coupled to a second portion of the continuous beam. The first portion of the continuous beam is coupled to a respective portion of the proof mass, and the second portion of the continuous beam is coupled to a respective portion of the substrate. The first and second portions of the continuous beam come together at an acute angle. The first and second piezoelectric stress sensors output stress information responsive to a stress induced in the continuous beam by displacement of the proof mass.