Patents Assigned to Cirrus Logic, Inc.
  • Patent number: 10785567
    Abstract: A method of fabricating a piezoelectric transducer may include interleaving a plurality of layers of piezoelectric material with a plurality of conductive layers including a first conductive layer, one or more second conductive layers, and one or more third conductive layers, coupling the first conductive layer to a first electrode, wherein an electrical impedance of the first conductive layer varies as a function of a temperature internal to the piezoelectric transducer, and such that a measurement signal indicative of the electrical impedance is generated at the first electrode, coupling the one or more second conductive layers to a second electrode, and coupling the one or more third conductive layers to a third electrode, such that an electrical driving signal driven to the second electrode and the third electrode causes mechanical vibration of the piezoelectric transducer as a function of the electrical driving signal.
    Type: Grant
    Filed: June 16, 2020
    Date of Patent: September 22, 2020
    Assignee: Cirrus Logic, Inc.
    Inventors: Nicholas Roche, Anthony S. Doy, Itisha Tyagi
  • Patent number: 10785568
    Abstract: In accordance with embodiments of the present disclosure, an apparatus for providing an output signal to an audio transducer may include a control circuit. The control circuit may be configured to predict, based on a magnitude of a signal indicative of the output signal, an occurrence of an event for changing a selectable digital gain and a selectable analog gain and an audio signal path, and responsive to predicting the occurrence of the event, change, at an approximate time in which a zero crossing of the signal indicative of the output signal occurs, the selectable digital gain and the selectable analog gain.
    Type: Grant
    Filed: August 25, 2014
    Date of Patent: September 22, 2020
    Assignee: Cirrus Logic, Inc.
    Inventors: Tejasvi Das, Ku He, John L. Melanson
  • Patent number: 10782361
    Abstract: Circuits for monitoring a socket are disclosed, including a circuit comprising a first node arranged to be electrically connected to a first pole of an electrical plug when the electrical plug is inserted into a corresponding socket, a second node arranged to be connected to a first voltage, wherein the first node is arranged to be connected to the first pole when the electrical plug is inserted into the socket, a variable resistance connected between the first node and a third node, wherein the third node is arranged to receive a second voltage, detection circuit arranged to detect the presence of the electrical plug or moisture in the socket based on a voltage at the first node, and a control circuit arranged to control the variable resistance to a first resistance value and, in response to the detection circuit detecting the presence of the electrical plug or moisture in the socket when the variable resistance is at the first resistance value, to a second resistance value, whereby the detection circuit dis
    Type: Grant
    Filed: February 27, 2018
    Date of Patent: September 22, 2020
    Assignee: Cirrus Logic, Inc.
    Inventors: Jonathan Taylor, Robert Rand, Charles Keepax
  • Patent number: 10782785
    Abstract: A method for quantifying fidelity of a haptic signal may include receiving a response signal indicative of a vibrational response of a vibrational transducer to a haptic playback waveform driven to the vibrational transducer, perceptually filtering the response signal to obtain human haptic-perceptible components of the response signal, and quantifying fidelity of the haptic playback waveform based on at least one quantitative characteristic of the human haptic-perceptible components of the response signal.
    Type: Grant
    Filed: January 25, 2019
    Date of Patent: September 22, 2020
    Assignee: Cirrus Logic, Inc.
    Inventors: Rong Hu, Jie Su, Harsha Rao
  • Patent number: 10778173
    Abstract: A method for compensating for a change in back electric motive force in a transducer in a device, wherein the transducer is driven by an output signal output by an amplifier, and a back volume of the transducer is formed by an enclosure within the device. The method comprises: receiving an input signal; determining, based on a characteristic of the transducer that the transducer has moved from an equilibrium position within the device; and based on the determination, adjusting a gain applied to the input signal by the amplifier to generate the output signal.
    Type: Grant
    Filed: October 24, 2018
    Date of Patent: September 15, 2020
    Assignee: Cirrus Logic, Inc.
    Inventors: Hezi Zhu, Roberto Napoli, Jie Su, Waleed Eshmawy
  • Patent number: 10779097
    Abstract: A device (10) for connection to an audio accessory (20) comprising: a jack socket (14) for connection to a jack plug (25) of the audio accessory (20), a ground connection to a first socket contact (428) which is positioned to mate with a ground return pole of the plug (25). The jack socket (14) comprises a second contact (432) also positioned to mate with the ground return pole of the plug (25). Driver amplifiers (416, 418) comprise an input coupled to the second contact (432) and are configured to superimpose a signal present at the second contact (432) onto received speaker signal. It may achieve reducing the crosstalk which could distort or blur the stereo image.
    Type: Grant
    Filed: April 10, 2019
    Date of Patent: September 15, 2020
    Assignee: Cirrus Logic, Inc.
    Inventors: Jonathan Taylor, ChunFeng Gu
  • Patent number: 10771047
    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 synchronise 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 synchronised to the first clock signal. In some embodiments the delay element (106) is a digital delay element which is synchronised to the first clock signal.
    Type: Grant
    Filed: July 8, 2019
    Date of Patent: September 8, 2020
    Assignee: Cirrus Logic, Inc.
    Inventor: John Paul Lesso
  • Patent number: 10771021
    Abstract: A system for thermally protecting an amplifier driving a capacitive load may include a low-pass filter configured to filter, with a variable cutoff frequency, an input signal to generate a filtered input signal, wherein the amplifier is configured to receive the filtered input signal and amplify the filtered input signal to generate a driving signal to the capacitive load and a controller configured to receive a real-time estimate of a temperature associated with the amplifier and vary the variable cutoff frequency as a function of the temperature.
    Type: Grant
    Filed: February 6, 2019
    Date of Patent: September 8, 2020
    Assignee: Cirrus Logic, Inc.
    Inventor: Eric Lindemann
  • Patent number: 10770086
    Abstract: A method may include receiving a stream of serial pulse-density modulation (PDM) data representing a first channel of data synchronized with a rising edge of a clock associated with the serial PDM data and a second channel of data synchronized with a falling edge of the clock, wherein each of the first channel of data and the second channel of data include encoded datagrams wherein each encoded datagram comprises more than one digital bit, detecting an invalid state associated with the stream, and responsive to detecting the invalid state, determining boundaries of each encoded datagram of the stream based on where within the stream the invalid state occurred.
    Type: Grant
    Filed: October 25, 2018
    Date of Patent: September 8, 2020
    Assignee: Cirrus Logic, Inc.
    Inventors: Masoud Farshbaf Zinati, Arun Ramani, Amar Vellanki, Xiaofan Fei
  • Patent number: 10770076
    Abstract: A method of detecting a replay attack on a voice biometrics system comprises: receiving an audio signal representing speech; detecting a magnetic field; determining if there is a correlation between the audio signal and the magnetic field; and if there is a correlation between the audio signal and the magnetic field, determining that the audio signal may result from a replay attack.
    Type: Grant
    Filed: June 27, 2018
    Date of Patent: September 8, 2020
    Assignee: Cirrus Logic, Inc.
    Inventors: César Alonso, John Paul Lesso
  • Patent number: 10764681
    Abstract: A system may include an input configured to receive a digital audio input signal having at least four and fewer than 65,000 quantization levels and sampled at at least 500 kilohertz, a low-pass filter configured to receive the digital audio input signal and perform filtering on the digital audio input signal to generate a filtered digital audio input signal having a bandwidth of between approximately 100 hertz and 10 kilohertz, a digital-to-analog converter configured to receive the filtered digital audio input signal and convert the filtered digital audio input signal into an equivalent analog audio input signal, and a driver configured to receive the equivalent analog audio input signal and drive an analog audio output signal to a transducer, wherein a group delay from the input to an output of the driver is less than 50 microseconds.
    Type: Grant
    Filed: July 25, 2019
    Date of Patent: September 1, 2020
    Assignee: Cirrus Logic, Inc.
    Inventor: John L. Melanson
  • Patent number: 10762905
    Abstract: A method for use in speaker verification, comprises: receiving a sample of a person's speech; estimating a noise measure in the received sample of the person's speech; if the estimated noise measure does not meet a predetermined criterion, rejecting the received sample of the person's speech; and if the estimated noise measure meets the predetermined criterion: adding noise to the received sample to form a sample with increased noise; extracting features of the sample with increased noise; and forming a model of the person's speech from the extracted features.
    Type: Grant
    Filed: July 31, 2018
    Date of Patent: September 1, 2020
    Assignee: Cirrus Logic, Inc.
    Inventors: Carlos Vaquero Avilés-Casco, David Martínez González
  • Patent number: 10763811
    Abstract: A system may include a digital modulator configured to modulate an input signal received at an input of the digital modulator to generate a modulated input signal at an output of the digital modulator, a digital gain element having a digital gain and coupled to the digital modulator, an open-loop Class-D amplifier coupled to an output of the digital modulator and configured to amplify the modulated input signal, wherein the open-loop Class-D amplifier is powered from a variable power supply having a variable supply voltage which is variable in response to one or more characteristics of the input signal, and a control circuit configured to control the digital gain to approximately cancel changes in an analog gain of the open-loop Class-D amplifier due to variation in the variable supply voltage in response to the one or more characteristics of the input signal.
    Type: Grant
    Filed: November 6, 2018
    Date of Patent: September 1, 2020
    Assignee: Cirrus Logic, Inc.
    Inventors: Lei Zhu, Tejasvi Das, John L. Melanson, Wai-shun Wilson Shum, Jing Bai, Xin Zhao, Xiaofan Fei
  • Patent number: 10756709
    Abstract: A system may include a driver for driving an output signal to a load, a pre-driver for driving a pre-driver signal to the driver, the pre-driver having a variable drive strength, and a controller configured to control the variable drive strength based on at least one measured physical quantity to compensate for variation of an output signal edge rate due to variations in the at least one measured physical quantity.
    Type: Grant
    Filed: June 12, 2019
    Date of Patent: August 25, 2020
    Assignee: Cirrus Logic, Inc.
    Inventors: Mengde Wang, Akhilesh Persha, Eric B. Smith, Vamsikrishna Parupalli
  • Patent number: 10755697
    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: April 24, 2019
    Date of Patent: August 25, 2020
    Assignee: Cirrus Logic, Inc.
    Inventors: Robert James Hatfield, Michael Page
  • Patent number: 10756689
    Abstract: A system may include an input configured to receive a first signal representative of a second signal to be driven to an amplifier input of an amplifier, processing circuitry configured to process the first signal in order to generate the second signal from the first signal such that the processing circuitry limits a current driven by the amplifier to an output load of the amplifier, and an output configured to drive the second signal to the amplifier input.
    Type: Grant
    Filed: June 6, 2018
    Date of Patent: August 25, 2020
    Assignee: Cirrus Logic, Inc.
    Inventors: Eric Lindemann, John L. Melanson, Eric J. King
  • Patent number: 10749864
    Abstract: A speaker recognition system for authenticating a mobile device user includes an enrollment and learning software module, a voice biometric authentication software module, and a secure software application. Upon request by a user of the mobile device, the enrollment and learning software module displays text prompts to the user, receives speech utterances from the user, and produces a voice biometric print. The enrollment and training software module determines when a voice biometric print has met at least a quality threshold before storing it on the mobile device. The secure software application prompts a user requiring authentication to repeat an utterance based at least on an attribute of a selected voice biometric print, receives a corresponding utterance, requests the voice biometric authentication software module to verify the identity of the second user using the utterance, and, if the user is authenticated, imports the voice biometric print.
    Type: Grant
    Filed: January 25, 2018
    Date of Patent: August 18, 2020
    Assignee: Cirrus Logic, Inc.
    Inventor: Marta Garcia Gomar
  • Patent number: 10750291
    Abstract: The application describes MEMS transducers having a patterned membrane electrode which incorporates a plurality of openings or voids. A conductive element is provided on the surface of the underlying membrane within the opening.
    Type: Grant
    Filed: May 23, 2018
    Date of Patent: August 18, 2020
    Assignee: Cirrus Logic, Inc.
    Inventors: Marek Sebastian Piechocinski, Richard Ian Laming, Tsjerk Hans Hoekstra, Colin Robert Jenkins, Axel Thomsen
  • Patent number: 10749431
    Abstract: A DC-DC converter and corresponding method for transitioning between a discontinuous conduction mode, DCM, and a continuous conduction mode, CCM, wherein the DC-DC converter is configured to power a signal processing system within an integrated circuit, is provided. The method comprises receiving input data, wherein the input data is for inputting into the signal processing system; determining an amplitude of the input data; and transitioning between DCM and CCM based on the amplitude of the input data. A DC-DC converter and respective method for transitioning from CCM to DCM comprising determining an estimated current representative of an inductor current through an inductor of the DC-DC converter; and transitioning from CCM to DCM based on the estimated current, is provided.
    Type: Grant
    Filed: December 20, 2018
    Date of Patent: August 18, 2020
    Assignee: Cirrus Logic, Inc.
    Inventors: Ullas Pazhayaveetil, Sarang Vadnerkar, Theodore M. Burk, Jeffrey May
  • Patent number: 10730747
    Abstract: The present application relates to MEMS transducer comprising a membrane electrode and a backplate electrode. The membrane electrode comprises primary and secondary openings.
    Type: Grant
    Filed: November 2, 2018
    Date of Patent: August 4, 2020
    Assignee: Cirrus Logic, Inc.
    Inventor: Colin Robert Jenkins