Patents Assigned to Cirrus Logic, Inc.
  • Patent number: 10348275
    Abstract: There is disclosed configurable frequency-divider circuitry for generating a target signal of a frequency Fr/Di based on a reference signal of a frequency Fr, where Di is an integer divider ratio, the frequency-divider circuitry comprising: N divider stages organised into a ring, each stage configured to receive an input signal and generate an output signal, with the output signal of each successive stage in the ring being the input signal of the next stage in the ring, wherein: the ring of stages is controlled by the reference signal so that the output signals are governed by the reference signal; the target signal is one of the output signals or a signal derived therefrom; and at least one of the stages is a configurable stage, whose mode of operation is configurable based on a configuration signal to configure the value of Di.
    Type: Grant
    Filed: July 19, 2018
    Date of Patent: July 9, 2019
    Assignee: Cirrus Logic, Inc.
    Inventors: Dario San Martin Molina, Gordon James Bates
  • Patent number: 10343901
    Abstract: The application describes MEMS transducer having a flexible membrane and which seeks to alleviate and/or redistribute stresses within the membrane layer. A membrane having a first/active region and a second/inactive region is described.
    Type: Grant
    Filed: January 25, 2016
    Date of Patent: July 9, 2019
    Assignee: Cirrus Logic, Inc.
    Inventors: Scott Lyall Cargill, Colin Robert Jenkins, Euan James Boyd, Richard Ian Laming
  • Patent number: 10343894
    Abstract: The application describes a MEMS transducer comprising a layer of conductive material provided on a surface of a layer of membrane material. The layer of conductive material comprises first and second regions, wherein the thickness and/or the conductivity of the/each first and second regions is different.
    Type: Grant
    Filed: August 14, 2017
    Date of Patent: July 9, 2019
    Assignee: Cirrus Logic, Inc.
    Inventors: Stephen Duffy, Colin Robert Jenkins, Tsjerk Hans Hoekstra
  • Patent number: 10349173
    Abstract: A nonlinear control system and a loudspeaker protection system. In particular, a nonlinear control system including a controller, an audio system, and a model is disclosed. The controller is configured to accept one or more input signals, and one or more estimated states produced by the model to produce one or more control signals. The audio system includes one or more transducers configured to accept the control signals to produce a rendered audio stream therefrom. An active loudspeaker with an integrated amplifier is disclosed. A loudspeaker protection system and a quality control system are disclosed. More particularly, a system for clamping the input to a loudspeaker dependent upon a bank of representative models is disclosed.
    Type: Grant
    Filed: July 14, 2017
    Date of Patent: July 9, 2019
    Assignee: CIRRUS LOGIC, INC.
    Inventors: Pär Gunnars Risberg, Erik Lindahl, Marcus Arvidsson, Daniel Stahre, Landy Toth
  • Patent number: 10348282
    Abstract: This application relates to time-encoding modulators (TEMs). A TEM (100) receives an input signal (SIN) and outputs a time encoded signal (SPWM). A comparator (101) is located within a forward signal path of a feedback loop of the TEM. Also in the feedback loop are a filter (104) and a delay element (106) for applying a controlled delay. In some embodiments a latching element (101, 302; 106, 402) is located within the forward signal path to synchronize any signal transitions output from the latching element to a received first clock signal. Any signal transitions in the output (SOUT) from the modulator are thus synchronized to the first clock signal. In some embodiments the delay element (106) is a digital delay element which is synchronized to the first clock signal.
    Type: Grant
    Filed: July 31, 2018
    Date of Patent: July 9, 2019
    Assignee: Cirrus Logic, Inc.
    Inventor: John Paul Lesso
  • Patent number: 10340796
    Abstract: In accordance with embodiments of the present disclosure, a controller for controlling at least one switch of a switching converter may include a current estimator configured to determine an estimated inductor current through an inductor of the switching converter based on a previous sample of a current through the inductor and a switch control configured to control activation and deactivation of the at least one switch based on the estimated inductor current.
    Type: Grant
    Filed: May 9, 2016
    Date of Patent: July 2, 2019
    Assignee: Cirrus Logic, Inc.
    Inventor: Xiangcheng Wang
  • Patent number: 10338883
    Abstract: A nonlinear control system and a speaker protection system are disclosed. In particular, a control system for adapting an audio output from a speaker in the proximity of an object is disclosed. The controller is configured to accept one or more input signals, and one or more estimated states produced by the model to produce one or more control signals. A speaker protection system and a quality control system are disclosed. More particularly, a system for clamping the input to a speaker dependent upon an estimate of the proximity, acoustic volume, and/or acoustic coupling of the speaker to a nearby object is disclosed.
    Type: Grant
    Filed: May 20, 2016
    Date of Patent: July 2, 2019
    Assignee: Cirrus Logic, Inc.
    Inventors: Pär Gunnars Risberg, Carl Lennart Stahl, Landy Toth
  • Patent number: 10341767
    Abstract: Speaker protection may be based on multiple speaker models with oversight logic that controls the speaker protection based on the multiple speaker models. At least one of the speaker models may be based on a speaker excursion determined from feedback information from the speaker, such as a current or voltage measured at the speaker. Excursion based on the speaker feedback may be used to determine an error in an excursion prediction made from the audio signal. The excursion prediction may then be compensated for that error. In some embodiments, a direct displacement estimate of excursion generated from speaker monitor signals is used to correct a fixed excursion model applied to an input audio signal.
    Type: Grant
    Filed: October 24, 2017
    Date of Patent: July 2, 2019
    Assignee: Cirrus Logic, Inc.
    Inventors: Jason Lawrence, Roberto Napoli, Rong Hu
  • Patent number: 10341768
    Abstract: A speaker model may implement a direct voltage-to-excursion model in an adaptive filter for modeling the speaker without developing a first electrical-only model and then converting the model to a mechanical model. The voltage-to-excursion model may allow for modeling of different kinds of speakers, such as sealed, ported, or vented speakers. A transfer function may be developed in the adaptive filter for the voltage-to-excursion model, and that transfer function re-used for prediction of excursion values based on an audio signal. Speaker protection may be performed to take steps to prevent speaker damage when a predicted excursion value exceeds safe limits. The voltage-to-excursion model may operate in displacement or displacement-related domains (e.g., velocity and back emf).
    Type: Grant
    Filed: November 7, 2017
    Date of Patent: July 2, 2019
    Assignee: Cirrus Logic, Inc.
    Inventors: Rong Hu, Roberto Napoli, Jie Su
  • Patent number: 10332541
    Abstract: A method for estimating and minimizing a noise power level difference (NPLD) between a primary channel and a reference channel of an audio device, includes receiving, by a primary channel, an audio signal that has a speech signal level and a noise signal level; receiving, by a reference channel, the audio signal with another speech signal level and another noise signal level; using the reference channel to estimate the noise signal level in the primary channel by reducing the another speech signal level; and compensating for a difference between the noise signal level and the another noise signal level to minimize a noise power level difference NPLD between the primary channel and the reference channel.
    Type: Grant
    Filed: October 11, 2017
    Date of Patent: June 25, 2019
    Assignee: Cirrus Logic, Inc.
    Inventor: Jan S. Erkelens
  • Patent number: 10331400
    Abstract: A method of processing an audio signal comprising a plurality of audio samples, the method comprising: receiving an audio sample of the plurality of audio samples; on determining that a peak amplitude of the audio sample falls outside a threshold range: suppressing the audio sample to within the threshold range by applying a strictly increasing non-linear function to the audio sample; and outputting the suppressed audio sample; and on determining that the peak amplitude of the audio sample falls within the threshold range or is equal to an upper or lower limit of the threshold range: outputting the received audio sample.
    Type: Grant
    Filed: February 22, 2018
    Date of Patent: June 25, 2019
    Assignee: Cirrus Logic, Inc.
    Inventor: Henry Chen
  • Patent number: 10334339
    Abstract: A MEMS transducer package (1) comprises a semiconductor die element (3) and a cap element (23). The semiconductor die element (3) and cap element (23) have mating surfaces (9, 21). The semiconductor die element (3) and cap element (23) are configured such that when the semiconductor die element (3) and cap element (4) are conjoined, a first volume (7, 27) is formed through the semiconductor die element (3) and into the semiconductor cap element (23), and an acoustic channel is formed to provide an opening between a non-mating surface (11) of the semiconductor die element (3) and a side surface (10, 12) of the transducer package.
    Type: Grant
    Filed: December 4, 2015
    Date of Patent: June 25, 2019
    Assignee: Cirrus Logic, Inc.
    Inventors: John Laurence Pennock, Tsjerk Hoekstra, David Talmage Patten
  • Patent number: 10334378
    Abstract: The application describes MEMS transducers comprising a flexible membrane layer supported in a fixed relation relative to a substrate along at least one supporting edge, wherein a plurality of slits are provided through the membrane layer. The slits define a plurality of beams. Each beam defines a path between first and second endpoints of the beam, the path comprising at least one change in direction. Also described are transducers wherein the membrane layer is supported in a fixed relation relative to the substrate along a plurality of supporting edges which define a membrane region that is substantially bounded by the supporting edges.
    Type: Grant
    Filed: July 26, 2017
    Date of Patent: June 25, 2019
    Assignee: Cirrus Logic, Inc.
    Inventor: Euan James Boyd
  • Patent number: 10334361
    Abstract: A loudspeaker driver circuit, comprises: at least one input for receiving an input signal; a loudspeaker protection module coupled to the input for receiving the input signal and for generating a modified signal in response to the input signal; an amplifier coupled to receive the modified signal from the loudspeaker protection module and to generate an output signal; an output for outputting the output signal for driving a speaker; and an ultrasonic signal generator, for generating an ultrasonic signal, wherein the ultrasonic signal generator is coupled to the amplifier for applying the ultrasonic signal thereto.
    Type: Grant
    Filed: April 27, 2018
    Date of Patent: June 25, 2019
    Assignee: Cirrus Logic, Inc.
    Inventor: Cedric Andrieu
  • Patent number: 10333395
    Abstract: A bipolar output charge pump circuit having a network of switching paths for selectively connecting an input node and a reference node for connection to an input voltage, a first pair of output nodes and a second pair of output nodes, and two pairs of flying capacitor nodes, and a controller for controlling the switching of the network of switching paths. The controller is operable to control the network of switching paths when in use with two flying capacitors connected to the two pairs of flying capacitor nodes, to provide a first bipolar output voltage at the first pair of output nodes and a second bipolar output voltage at the second pair of bipolar output nodes.
    Type: Grant
    Filed: June 29, 2018
    Date of Patent: June 25, 2019
    Assignee: Cirrus Logic, Inc.
    Inventors: John P. Lesso, Peter J. Firth, John L. Pennock
  • Patent number: 10324113
    Abstract: The overall performance of a current sense amplifier system may be improved by increasing the common mode rejection of the system. In particular, improved current sense amplifiers may be configured to use a first signal path coupled to the amplifier and a first input terminal, wherein the first signal path is configured to measure the current through a device by generating a voltage proportional to the measured current, wherein the generated voltage includes a small signal voltage with a large common mode voltage, and a second signal path coupled to the amplifier and the first input terminal, wherein the second signal path is configured to reduce the common mode of the generated voltage by level shifting the generated voltage to reduce the common mode voltage.
    Type: Grant
    Filed: March 14, 2016
    Date of Patent: June 18, 2019
    Assignee: Cirrus Logic, Inc.
    Inventors: Vamsikrishna Parupalli, Itisha Tyagi
  • Patent number: 10319361
    Abstract: A digital circuit arrangement for an ambient noise-reduction system affording a higher degree of noise reduction than has hitherto been possible. The arrangement converts the analog signals into N-bit digital signals at sample rate f0, and then subjects the converted signals to digital filtering. The value of N in some embodiments is 1 but, in any event, is no greater than 8, and f0 may be 64 times the Nyquist sampling rate but, in any event, is substantially greater than the Nyquist sampling rate. This permits digital processing to be used without incurring group delay problems that rule out the use of conventional digital processing in this context. Furthermore, adjustment of the group delay can readily be achieved, in units of a fraction of a micro-second, providing the ability to fine tune the group delay for feed forward applications.
    Type: Grant
    Filed: December 19, 2016
    Date of Patent: June 11, 2019
    Assignee: Cirrus Logic, Inc.
    Inventor: Richard Clemow
  • Patent number: 10321230
    Abstract: In accordance with embodiments of the present disclosure, a system may include a playback path and a control circuit. The playback path may have a playback input for receiving an input signal and configured to generate at a playback path output an output signal based on the input signal, wherein the playback path is configured to operate in a plurality of operational modes. The control circuit may be configured to receive a first signal from within the playback path and indicative of the input signal, receive a second signal generated from the input signal externally to the playback path, and select a selected operational mode from the plurality of operational modes based on the first signal and the second signal.
    Type: Grant
    Filed: April 7, 2017
    Date of Patent: June 11, 2019
    Assignee: Cirrus Logic, Inc.
    Inventors: Tejasvi Das, Xin Zhao, Ku He, Xiaofan Fei
  • Patent number: 10320337
    Abstract: A dynamic common reference input (CMRI) signal may be provided to an operational amplifier, or “op-amp,” in an amplifier system to reduce the common mode ripple of the fully-differential op-amp, while adding little or no noise in the amplifier system. The dynamic CMRI signal may be controlled such that a common-mode component of two amplifier input nodes of the operational amplifier is made approximately independent of two input signals received at two system input nodes of the amplifier system. An amplifier system with the dynamic CMRI may be used in class-D amplifiers, such as amplifiers for audio systems that generate output for headphones or speakers.
    Type: Grant
    Filed: January 27, 2017
    Date of Patent: June 11, 2019
    Assignee: Cirrus Logic, Inc.
    Inventors: Xin Zhao, Tejasvi Das, Hossein Mirzaie, Lei Zhu, Xiaofan Fei
  • Patent number: 10319372
    Abstract: Received data representing speech is stored, and a trigger detection block detects a presence of data representing a trigger phrase in the received data. In response, a first part of the stored data representing at least a part of the trigger phrase is supplied to an adaptive speech enhancement block, which is trained on the first part of the stored data to derive adapted parameters for the speech enhancement block. A second part of the stored data, overlapping with the first part of the stored data, is supplied to the adaptive speech enhancement block operating with said adapted parameters, to form enhanced stored data. A second trigger phrase detection block detects the presence of data representing the trigger phrase in the enhanced stored data. In response, enhanced speech data are output from the speech enhancement block for further processing, such as speech recognition.
    Type: Grant
    Filed: August 28, 2017
    Date of Patent: June 11, 2019
    Assignee: Cirrus Logic, Inc.
    Inventors: Robert James Hatfield, Michael Page