Microphone assembly with disturbance compensation
AssigneeKnowles Electronics, LLC
InventorsJakob Kenn Toft, Mohammad Shajaan, Claus Erdmann Fürst
Life of this patent
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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.
Claims20
A transducer assembly comprising:
- a transduction element comprising a movable member, the transduction element configured to produce a mechanical output in response to an excitation signal or produce an electrical signal in response to actuation of the movable member;
- a bias circuit having an adjustable output voltage coupled to the transduction element;
- a sensor coupled to the transduction element and configured to generate a feedback signal in response to a disturbance on the transduction element;
- a servo-loop controller coupled to the sensor and to the bias circuit, the servo-loop controller configured to selectively suppresses frequency content associated with the disturbance by regulating the output voltage of the bias circuit based on the feedback signal;
- wherein the bias circuit comprises a bidirectional charge pump configured to increase or decrease the output voltage of the bias circuit.
A transducer assembly comprising:
- a housing having an external interface;
- a microelectromechanical systems (MEMS) motor disposed in the housing and comprising a movable member, the MEMS motor devoid of a barometric pressure relief vent and configured to produce a mechanical output in response to an excitation signal or produce an electrical signal in response to movement of the movable member;
- a bias circuit having an adjustable output voltage coupled to the MEMS motor;
- a sensor coupled to the MEMS motor and configured to generate a feedback signal based on an effect of a disturbance on the transducer assembly having frequency content inside or outside a desired bandwidth of the transducer assembly;
- a servo-loop controller coupled to the sensor and to the bias circuit, the servo-loop controller configured to compensate for the disturbance by adjusting the output voltage of the bias circuit based on the feedback signal;
- wherein the bias circuit comprises a multistage charge pump configured to provide bidirectional flow of charge to and from the MEMS motor, and wherein the output voltage of the bias circuit is increased or decreased based on the feedback signal.
A transducer assembly comprising:
- a transduction element comprising a movable member, the transduction element configured to produce a mechanical output in response to an excitation signal or produce an electrical signal in response to actuation of the movable member;
- a bias circuit having an adjustable output voltage coupled to the transduction element;
- a sensor coupled to the transduction element and configured to generate a feedback signal in response to a disturbance on the transduction element;
- a servo-loop controller coupled to the sensor and to the bias circuit, the servo-loop controller configured to selectively suppresses frequency content associated with the disturbance by regulating the output voltage of the bias circuit based on the feedback signal;
- a signal processing path configured to provide an output signal, based on the feedback signal, to an external interface wherein the servo-loop controller comprises a loop bandwidth greater than the desired bandwidth of the transducer assembly.
Dependencies are inferred from the claim text.