Knowles Electronics, Inc.

Weiwen Dai

Mark Niederberger

Jordan Schultz

Robert A Popper

Luca Bettini

Vezio Malandruccolo

Peter V Loeppert

Peter Van Kessel

The disclosure relates generally to microphone and vibration sensor assemblies () having a transducer (), like a microelectromechanical systems (MEMS) device, and an electrical circuit () disposed in a housing () configured for integration with a host device. The electrical circuit includes a transducer bias circuit that applies a bias to the transducer and a bias control circuit () that compensates for transducer sensitivity drift caused by variation in an environmental condition of the transducer, and electrical circuits therefor.

Microphone assembly with transducer sensitivity drift compensation and electrical circuit therefor

The disclosure relates generally to microphone and vibration sensor assemblies () having a transducer (), like a microelectromechanical systems (MEMS) device, and an electrical circuit () disposed in a housing () configured for integration with a host device. The electrical circuit includes a variable gain signal processing circuit () that processes an electrical signal from the transducer and a gain control circuit () that compensates for transducer sensitivity drift caused by variation in an environmental condition of the transducer, and electrical circuits therefor.

A microphone apparatus including a MEMS transducer, an acoustic activity detector, a local oscillator, and an external-device interface standardized for compatibility with devices from different manufacturers is disclosed. The microphone apparatus has a first mode of operation during which the apparatus is clocked by the internal clock signal when the acoustic activity detector processes digital data for acoustic activity, and a second mode of operation during which the microphone apparatus is clocked by an external clock signal received at the external-device interface after voice activity is detected by the acoustic activity detector.

Microphone and corresponding digital interface

Analog signals are received from a sound transducer. The analog signals are converted into digitized data. A determination is made as to whether voice activity exists within the digitized signal. Upon the detection of voice activity, an indication of voice activity is sent to a processing device. The indication is sent across a standard interface, and the standard interface is configured to be compatible to be coupled with a plurality of devices from potentially different manufacturers.

A microelectromechanical (MEMS) microphone includes a MEMS motor and a gain adjustment apparatus. The MEMS motor includes at least a diaphragm and a charge plate and is configured to receive sound energy and transform the sound energy into an electrical signal. The gain adjustment apparatus has an input and an output and is coupled to the MEMS motor. The gain adjustment apparatus is configured to receive the electrical signal from the MEMS motor at the input and adjust the gain of the electrical signal as measured from the output of the gain adjustment apparatus. The amount of gain is selected so as to obtain a favorable sensitivity for the microphone.

Sensitivity adjustment apparatus and method for MEMS devices

An the acoustic apparatus comprising a first MEMS motor that includes a first diaphragm and a first back plate, and a second MEMS motor that includes a second diaphragm and a second back plate. The first motor is biased with a first electrical polarity and a second motor is biased with a second electrical polarity such that the first electrical polarity and the second electrical polarity are opposite. At the first motor, a first signal is created that is representative of received sound energy. At the second motor, a second signal is created that is representative of the received sound energy. A differential output signal that is the representative of the difference between the first signal and the second signal is obtained. In obtaining the differential output signal, common mode noise between the first motor and the second motor is rejected.

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Elgin, IL, United States of America

Weiwen Dai