Abstract: The present disclosure relates to a transducer assembly including a transducer having a movable member, and a servo-loop controller configured to compensate for effects of a disturbance on the transducer assembly by adjusting a bias voltage applied to the transducer. A servo-loop controller having a smaller bandwidth for out-of-band disturbances than for in-band disturbances and configured to control the bias voltage based on a feedback signal generated by a sensor that detects an effect of the disturbance on the transducer assembly. The transducer assembly can be implemented as a microphone or a speaker among other sensors and actuators.

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 microphone assembly includes a transducer element and a processing circuit. The processing circuit includes an analog-to-digital converter (ADC) configured to receive, sample and quantize a microphone signal generated by the transducer element to generate a corresponding digital microphone signal. The processing circuit includes a feedback path including a digital loop filter configured to receive and filter the digital microphone signal to provide a first digital feedback signal and a digital-to-analog converter (DAC) configured to convert the first digital feedback signal into a corresponding analog feedback signal. The processing circuit additionally includes a summing node at the transducer output configured to combine the microphone signal and the analog feedback signal.

Abstract: A microphone assembly includes an acoustic filter with a first highpass cut-off frequency. The microphone assembly additionally includes a forward signal path and a feedback signal path. The forward signal path is configured to amplify or buffer an electrical signal generated by a transducer in response to sound and to convert the electrical signal to a digital signal. The feedback signal path is configured to generate a digital control signal based on the digital signal and to generate and output a sequence of variable current pulses based on the digital control signal. The variable current pulses suppress frequencies of the electrical signal below a second highpass cut-off frequency, higher than the first highpass cut-off frequency.

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: The present disclosure relates generally to a microphone assembly. The microphone assembly has an acoustic activity detection mode of operation when the electrical circuit is clocked using an internal clock signal generator in the absence of an external clock signal at a host interface, and an electrical circuit of the microphone assembly is configured to provide an interrupt signal to the host interface upon detection of acoustic activity by the electrical circuit. The electrical circuit is configured to control the operating mode of the microphone assembly based on a frequency of the external clock signal in response to providing the interrupt signal and is configured to provide data representing the electrical signal to the host interface using the external clock signal received at the host interface.

Abstract: A microphone assembly comprising: a housing including a base, a cover, and a sound port; a MEMS transducer element disposed in the housing, the transducer element configured to convert sound into a microphone signal voltage at a transducer output; and a processing circuit. The processing circuit comprising a transconductance amplifier comprising an input node connected to the transducer output for receipt of the microphone signal voltage, the transconductance amplifier being configured to generate an amplified current signal representative of the microphone signal voltage in accordance with a predetermined transconductance of the transconductance amplifier; and an analog-to-digital converter comprising an input node connected to receive the amplified current signal, said analog-to-digital converter being configured to sample and quantize the amplified current signal to generate a corresponding digital microphone signal.

Abstract: A microphone assembly includes an acoustic filter with a first highpass cut-off frequency. The microphone assembly additionally includes a forward signal path and a feedback signal path. The forward signal path is configured to amplify or buffer an electrical signal generated by a transducer in response to sound and to convert the electrical signal to a digital signal. The feedback signal path is configured to generate a digital control signal based on the digital signal and to generate and output a sequence of variable current pulses based on the digital control signal. The variable current pulses suppress frequencies of the electrical signal below a second highpass cut-off frequency, higher than the first highpass cut-off frequency.

Abstract: A microphone assembly includes an acoustic filter with a first highpass cut-off frequency. The microphone assembly additionally includes a forward signal path and a feedback signal path. The forward signal path is configured to amplify or buffer an electrical signal generated by a transducer in response to sound and to convert the electrical signal to a digital signal. The feedback signal path is configured to generate a digital control signal based on the digital signal and to generate and output a sequence of variable current pulses based on the digital control signal. The variable current pulses suppress frequencies of the electrical signal below a second highpass cut-off frequency, higher than the first highpass cut-off frequency.

Abstract: A microphone assembly includes a transducer element and a processing circuit. The processing circuit includes an analog-to-digital converter (ADC) configured to receive, sample and quantize a microphone signal generated by the transducer element to generate a corresponding digital microphone signal. The processing circuit includes a feedback path including a digital loop filter configured to receive and filter the digital microphone signal to provide a first digital feedback signal and a digital-to-analog converter (DAC) configured to convert the first digital feedback signal into a corresponding analog feedback signal. The processing circuit additionally includes a summing node at the transducer output configured to combine the microphone signal and the analog feedback signal.

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 microphone assembly includes a transducer element and a processing circuit. The processing circuit includes an analog-to-digital converter (ADC) configured to receive, sample and quantize a microphone signal generated by the transducer element to generate a corresponding digital microphone signal. The processing circuit includes a feedback path including a digital loop filter configured to receive and filter the digital microphone signal to provide a first digital feedback signal and a digital-to-analog converter (DAC) configured to convert the first digital feedback signal into a corresponding analog feedback signal. The processing circuit additionally includes a summing node at the transducer output configured to combine the microphone signal and the analog feedback signal.

Abstract: The present disclosure relates generally to a microphone assembly. The microphone assembly has an acoustic activity detection mode of operation when the electrical circuit is clocked using an internal clock signal generator in the absence of an external clock signal at a host interface, and an electrical circuit of the microphone assembly is configured to provide an interrupt signal to the host interface upon detection of acoustic activity by the electrical circuit. The electrical circuit is configured to control the operating mode of the microphone assembly based on a frequency of the external clock signal in response to providing the interrupt signal and is configured to provide data representing the electrical signal to the host interface using the external clock signal received at the host interface.

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 microphone assembly comprising: a housing including a base, a cover, and a sound port; a MEMS transducer element disposed in the housing, the transducer element configured to convert sound into a microphone signal voltage at a transducer output; and a processing circuit. The processing circuit comprising a transconductance amplifier comprising an input node connected to the transducer output for receipt of the microphone signal voltage, the transconductance amplifier being configured to generate an amplified current signal representative of the microphone signal voltage in accordance with a predetermined transconductance of the transconductance amplifier; and an analog-to-digital converter comprising an input node connected to receive the amplified current signal, said analog-to-digital converter being configured to sample and quantize the amplified current signal to generate a corresponding digital microphone signal.

Abstract: A microphone assembly includes a transducer and a processing circuit. The processing circuit includes an analog-to-digital converter (ADC) configured to receive, sample and quantize an electrical signal generated by the transducer to generate a corresponding digital signal. The processing circuit includes a feedback path including a digital loop filter configured to receive and filter the digital signal to provide a first digital feedback signal and a digital-to-analog converter (DAC) configured to convert the first digital feedback signal into a corresponding analog feedback signal. The processing circuit additionally includes a summing node configured to combine the electrical signal and the analog feedback signal.

Abstract: A microphone assembly includes an acoustic filter with a first highpass cut-off frequency. The microphone assembly additionally includes a forward signal path and a feedback signal path. The forward signal path is configured to amplify or buffer an electrical signal generated by a transducer in response to sound and to convert the electrical signal to a digital signal. The feedback signal path is configured to generate a digital control signal based on the digital signal and to generate and output a sequence of variable current pulses based on the digital control signal. The variable current pulses suppress frequencies of the electrical signal below a second highpass cut-off frequency, higher than the first highpass cut-off frequency.

Abstract: A microphone assembly includes an acoustic sensor configured to produce an electrical signal and an electrical circuit including a voice activity detector coupled to an output of the acoustic sensor. The microphone assembly further includes an internal clock signal generator and a host interface coupled to the electrical circuit. The host interface has external connections including an external clock signal and a data connection. The microphone assembly includes an acoustic activity detection mode of operation when the electrical circuit is clocked by the internal clock signal generator in the absence of an external clock signal at the host interface. The microphone assembly has a plurality of operating modes controlled by an external clock signal received in response to an interrupt signal provided by the electrical circuit. The electrical circuit is configured to provide data representing the electrical signal at the host interface when the external clock signal is received.

Abstract: A microphone assembly includes an acoustic transducer element configured to convert sound into a microphone signal in accordance with a transducer frequency response including a first highpass cut-off frequency. The microphone assembly additionally includes a processing circuit including a signal amplification path configured to receive, sample and digitize the microphone signal to provide a digital microphone signal. A frequency response of the signal amplification path includes a second highpass cut-off frequency which is higher than the first highpass cut-off frequency of the acoustic transducer element.

Abstract: The present disclosure relates to microphone apparatus. One microphone apparatus includes an acoustic sensor, an electrical circuit including an acoustic activity detector, a frequency detection circuit and a control block, an internal clock signal generator coupled to the electrical circuit, and a host interface with external connections including a connection for an external clock signal and data. The microphone assembly has an acoustic activity detection mode of operation when the electrical circuit is clocked using the internal clock signal generator in the absence of an external clock signal at the host interface, and the electrical circuit is configured to provide an interrupt signal to the host interface upon detection of acoustic activity by the electrical circuit.