Abstract: The disclosure pertains to an audio signal processing system that offers low latency without sacrificing various desirable features such as large dynamic operating range and low power consumption. Low latency is achieved by generating a feed-forward signal that is based in part on performing high-pass filtering and threshold crossing detection upon an amplified transducer signal. The feed-forward signal is provided to a controller, which uses the feed-forward signal to produce a feedback signal that controls one or more operating parameters of one or more components of the audio signal processing system. The feedback signal produced in this manner avoids incurring a delay associated with propagating the amplified transducer signal to the controller via an analog-to-digital converter (ADC) for purposes of generating the feedback signal. Generation, and use, of the feed-forward signal also allows the audio amplifier to rapidly adjust to amplitude changes in audio signals received from the transducer.

Abstract: Aspects of transducers with feedback transduction are described. One aspect is a transducer system comprising an operational amplifier having an inverting input, a non-inverting input, and an output. The transducer system also includes a piezoelectric microelectromechanical system (MEMS) transducer having a first node and a second node, wherein the first node is coupled to the inverting input of the operational amplifier, and wherein the piezoelectric MEMS transducer is configured to generate an electrical signal across the first node and the second node in response to a signal incident upon the piezoelectric MEMS transducer. The transducer system also includes an attenuator having an input and an output, wherein the input of the attenuator is coupled to the output of the operational amplifier, and wherein the output of the attenuator is coupled to the second node of the piezoelectric MEMS transducer.

Abstract: The disclosure pertains to an audio signal processing system that offers low latency without sacrificing various desirable features such as large dynamic operating range and low power consumption. Low latency is achieved by generating a feed-forward signal that is based in part on performing high-pass filtering and threshold crossing detection upon an amplified transducer signal. The feed-forward signal is provided to a controller, which uses the feed-forward signal to produce a feedback signal that controls one or more operating parameters of one or more components of the audio signal processing system. The feedback signal produced in this manner avoids incurring a delay associated with propagating the amplified transducer signal to the controller via an analog-to-digital converter (ADC) for purposes of generating the feedback signal. Generation, and use, of the feed-forward signal also allows the audio amplifier to rapidly adjust to amplitude changes in audio signals received from the transducer.

Abstract: Illustrative embodiments enable a MEMS transducer to quickly recover from, acoustic overload events by quickly resetting signal processing circuitry downstream from a MEMS transducer. An acoustic overload sensor detects occurrence of an acoustic overload event, and triggers a reset circuit to operate a set of switches to rapidly drain charge from a corresponding set of capacitances within the transducer, or within the signal processing circuitry, thereby resetting the signal processing circuitry more rapidly than would occur if said transducer or circuitry were allowed to recover on its own.

Abstract: A device that includes an adaptive acoustic detection circuit and an acoustic sensor device such as a microphone is described. The device includes in addition to the sensor a circuit configured to detect when an input stimulus to the sensor satisfies an adaptive threshold, and further configured to produce a signal upon detection that causes adjustment of performance of the device, wherein the adaptive threshold is a threshold value that varies over time in accordance with detected changes to sound of an environment in which the device is located.

Abstract: An apparatus for testing a transducer module includes a test signal generator coupled to a common-mode terminal common to a plurality of transducers, and a signal processing circuit configured to receive output signal from each of said transducers and to produce an output signal. If the transducers are well matched to one another, the output signal will have little or no output amplitude. If there is a mismatch between the transducers, however, the output signal will have an amplitude proportional to the mismatch. The amplitude of the output signal may be compared to a predetermined threshold in order to produce a mismatch output signal indicating the existence of, and/or the degree of, mismatch between the transducers.

Abstract: Aspects of transducers with feedback transduction are described. One aspect is a transducer system comprising an operational amplifier having an inverting input, a non-inverting input, and an output. The transducer system also includes a piezoelectric microelectromechanical system (MEMS) transducer having a first node and a second node, wherein the first node is coupled to the inverting input of the operational amplifier, and wherein the piezoelectric MEMS transducer is configured to generate an electrical signal across the first node and the second node in response to a signal incident upon the piezoelectric MEMS transducer. The transducer system also includes an attenuator having an input and an output, wherein the input of the attenuator is coupled to the output of the operational amplifier, and wherein the output of the attenuator is coupled to the second node of the piezoelectric MEMS transducer.

Abstract: A device that includes an adaptive acoustic detection circuit and an acoustic sensor device such as a microphone is described. The device includes in addition to the sensor a circuit configured to detect when an input stimulus to the sensor satisfies an adaptive threshold, and further configured to produce a signal upon detection that causes adjustment of performance of the device, wherein the adaptive threshold is a threshold value that varies over time in accordance with detected changes to sound of an environment in which the device is located.

Abstract: An apparatus for testing a transducer module includes a test signal generator coupled to a common-mode terminal common to a plurality of transducers, and a signal processing circuit configured to receive output signal from each of said transducers and to produce an output signal. If the transducers are well matched to one another, the output signal will have little or no output amplitude. If there is a mismatch between the transducers, however, the output signal will have an amplitude proportional to the mismatch. The amplitude of the output signal may be compared to a predetermined threshold in order to produce a mismatch output signal indicating the existence of, and/or the degree of, mismatch between the transducers.

Abstract: Illustrative embodiments enable a MEMS transducer to quickly recover from, acoustic overload events by quickly resetting signal processing circuitry downstream from a MEMS transducer. An acoustic overload sensor detects occurrence of an acoustic overload event, and triggers a reset circuit to operate a set of switches to rapidly drain charge from a corresponding set of capacitances within the transducer, or within the signal processing circuitry, thereby resetting the signal processing circuitry more rapidly than would occur if said transducer or circuitry were allowed to recover on its own.

Abstract: A device that includes an adaptive acoustic detection circuit and an acoustic sensor device such as a microphone is described. The device includes in addition to the sensor a circuit configured to detect when an input stimulus to the sensor satisfies an adaptive threshold, and further configured to produce a signal upon detection that causes adjustment of performance of the device, wherein the adaptive threshold is a threshold value that varies over time in accordance with detected changes to sound of an environment in which the device is located.

Abstract: A device that includes an adaptive acoustic detection circuit and an acoustic sensor device such as a microphone is described. The device includes in addition to the sensor a circuit configured to detect when an input stimulus to the sensor satisfies an adaptive threshold, and further configured to produce a signal upon detection that causes adjustment of performance of the device, wherein the adaptive threshold is a threshold value that varies over time in accordance with detected changes to sound of an environment in which the device is located.