公开(公告)号：US11457312B1

公开(公告)日：2022-09-27

申请号：US17358485

申请日：2021-06-25

Applicant: Cirrus Logic International Semiconductor Ltd.

Inventor： Sandeep P. Sira

IPC: H04R3/02

Abstract: A device may include a housing, a transducer coupled to the housing for reproducing an audio signal including both a source audio signal for playback to a listener and an anti-noise signal for countering the effects of ambient audio sounds in an acoustic output of the transducer, an error microphone coupled to the housing in proximity to the transducer for providing an error microphone signal indicative of the acoustic output of the transducer and the ambient audio sounds at the transducer, and a processing circuit. The processing circuit may implement a feedback filter having a response that generates the anti-noise signal from a playback corrected error, the playback corrected error based on a difference between the error microphone signal and a secondary path estimate signal, an adaptive secondary path estimate filter configured to model an electro-acoustic path of the source audio signal and have a secondary path estimate response that generates the secondary path estimate signal from the source audio signal, and a coefficient control block that shapes the response of the secondary path estimate filter in conformity with a reference signal and an internal error signal in order to minimize the ambient audio sounds at the transducer, wherein the reference signal is equal to a sum of the source audio signal and the anti-noise signal.

公开(公告)号：US11664000B1

公开(公告)日：2023-05-30

申请号：US17496253

申请日：2021-10-07

Applicant: Cirrus Logic International Semiconductor Ltd.

Inventor： Ziyan Zou ,  K. Joshua Bodon ,  Sandeep P. Sira

IPC: G10K11/178

CPC classification number: G10K11/17823 ,  G10K11/17815 ,  G10K11/17854 ,  G10K11/17875 ,  G10K11/17885

Abstract: An integrated circuit may include an output for providing an output signal to a transducer including both a source audio signal for playback to a listener and an anti-noise signal for countering the effect of ambient audio sounds in an acoustic output of the transducer, an error microphone input for receiving an error microphone signal indicative of the output of the transducer and the ambient audio sounds at the transducer, and a processing circuit. The processing circuit may implement a feedback path comprising a feedback filter having a response that generates a feedback anti-noise signal based on the error microphone signal, the feedback filter comprising a plurality of biquad filters and wherein the anti-noise signal is generated from the feedback anti-noise signal and an event detection and oversight control that detects that an ambient audio event is occurring that could cause the feedback filter to generate an undesirable component in the anti-noise signal, and controls filter coefficients of one or more of the plurality of biquad filters to reduce the undesirable component.

公开(公告)号：US20240048903A1

公开(公告)日：2024-02-08

申请号：US17816489

申请日：2022-08-01

Applicant: Cirrus Logic International Semiconductor Ltd

Inventor： Sandeep P. Sira ,  Philip B. J. Clarkin ,  Roberto Napoli

IPC: H04R3/00 ,  H04R29/00

CPC classification number: H04R3/007 ,  H04R29/001

Abstract: This disclosure provides techniques for determining a reference resistance of a loudspeaker, such as in a mobile device. The reference resistance value may be used, among other applications, for speaker protection by reducing overdrive of the loudspeaker beyond safe temperature, which could damage the loudspeaker, while allowing driving of the loudspeaker closer to safety limits to improve performance of the loudspeaker. In a first aspect, a method of audio device monitoring includes applying a first signal to a loudspeaker; measuring a voltage and a current for the loudspeaker while applying the first signal to the loudspeaker; and determining a reference resistance for the loudspeaker based on the voltage and the current. Other aspects and features are also claimed and described.