Patents Assigned to Cirrus Logic, Inc.
  • Patent number: 11127390
    Abstract: A feedforward ambient noise reduction arrangement includes, within a housing, a loudspeaker device for directing sound energy into an ear of a listener. Disposed externally of the housing, and positioned to sense ambient noise on its way to the listener's ear, are plural microphone devices capable of converting the sensed ambient noise into electrical signals for application to the loudspeaker to generate an acoustic signal opposing the ambient noise. Importantly, the overall arrangement is such that the acoustic signal is generated by said loudspeaker means in substantial time alignment with the arrival of said ambient noise at the listener's ear.
    Type: Grant
    Filed: September 26, 2019
    Date of Patent: September 21, 2021
    Assignee: Cirrus Logic, Inc.
    Inventor: Alastair Sibbald
  • Patent number: 11119138
    Abstract: A method may include applying an excitation signal to a capacitor of the capacitive sensor which causes generation of a modulated signal from an input signal indicative of a variance in a capacitance of the capacitor, detecting the modulated signal with a detector to generate a detected modulated signal that has a phase shift relative to the excitation signal, demodulating the detected modulated signal into an in-phase component and a quadrature component using a reference signal, nullifying the quadrature component by setting a phase of the reference signal relative to the excitation signal to compensate for the phase shift, and outputting the in-phase component as an unmodulated output signal representative of the capacitance.
    Type: Grant
    Filed: April 2, 2020
    Date of Patent: September 14, 2021
    Assignee: Cirrus Logic, Inc.
    Inventors: Vikrant Arumugam, Amar Vellanki, Vamsikrishna Parupalli, Zhong You, Johann G. Gaboriau, John L. Melanson
  • Patent number: 11119134
    Abstract: A detector for measuring a resistance of a variable resistance sensor (VRS) that varies with respect to a time-varying stimulus (e.g., temperature) includes a voltage reference having variation with respect to operating conditions and a linearized digital-to-analog converter (LIDAC) having a known transconductance that uses the voltage reference to generate a current for pumping into the VRS to cause the VRS to generate a voltage sensed by the detector. The sensed voltage includes error due to the variation of the voltage reference. The detector also includes a programmable gain amplifier (PGA) that gains up the sensed voltage to generate an output signal, an ADC that converts the output signal to a digital value, and a digital processor that computes the resistance of the VRS using the digital value and the known transconductance. The PGA is non-varying with respect to the time-varying stimulus.
    Type: Grant
    Filed: August 2, 2019
    Date of Patent: September 14, 2021
    Assignee: Cirrus Logic, Inc.
    Inventors: Cory Jay Peterson, Chandra B. Prakash, Anand Ilango, Ramin Zanbaghi, Dejun Wang
  • Patent number: 11121690
    Abstract: This application relates to Class D amplifier circuits. A modulator controls a Class D output stage based on a modulator input signal (Dm) to generate an output signal (Vout) which is representative of an input signal (Din). An error block, which may comprise an ADC, generates an error signal (?) from the output signal and the input signal. In various embodiments the extent to which the error signal (?) contributes to the modulator input signal (Dm) is variable based on an indication of the amplitude of the input signal (Din). The error signal may be received at a first input of a signal selector block. The input signal may be received at a second input of the signal selector block. The signal selector block may be operable in first and second modes of operation, wherein in the first mode the modulator input signal is based at least in part on the error signal; and in the second mode the modulator input signal is based on the digital input signal and is independent of the error signal.
    Type: Grant
    Filed: August 27, 2019
    Date of Patent: September 14, 2021
    Assignee: Cirrus Logic, Inc.
    Inventors: John Paul Lesso, Toru Ido
  • Patent number: 11119524
    Abstract: A selectable output current mirror may include a reference leg configured to generate a reference current, an output leg electrically coupled to the reference leg in a manner such that the output leg is configured to generate at an output of the output leg an output current proportional to the reference current, wherein the output leg comprises an output leg transistor, a drain path switch coupled between a first non-gate terminal of the output leg transistor and the output of the output leg, and a series combination of a degeneration resistor and a degeneration path switch coupled between a second non-gate terminal of the output leg transistor and a voltage source to the selectable output current mirror.
    Type: Grant
    Filed: March 11, 2020
    Date of Patent: September 14, 2021
    Assignee: Cirrus Logic, Inc.
    Inventors: Christopher M. Dougherty, Anindya Bhattacharya, Vaibhav Pandey, Ying Ou
  • Patent number: 11121661
    Abstract: A method for minimizing settling of a moving mass of an electromagnetic load may include determining a polarity and a magnitude of a velocity of the moving mass based on real time measurements of one or more parameters associated with the electromagnetic load and based on the polarity and the magnitude of the velocity, generating a braking signal to be applied to the moving mass that opposes the polarity of the velocity.
    Type: Grant
    Filed: December 4, 2019
    Date of Patent: September 14, 2021
    Assignee: Cirrus Logic, Inc.
    Inventors: Marco Janko, Emmanuel Marchais, Carl Ståhl
  • Patent number: 11122350
    Abstract: A method for on ear detection for a headphone, the method comprising: receiving a first microphone signal derived from an first microphone of the headphone and determining, from the first microphone signal, a first resonance frequency associated with an acoustic port of the first microphone, the first resonance frequency dependent on a first temperature at the first microphone; receiving a second microphone signal derived from an second microphone of the headphone and determining, from the second microphone signal, a second resonance frequency associated with an acoustic port of the second microphone, the second resonance frequency dependent on a second temperature at the second microphone.
    Type: Grant
    Filed: August 18, 2020
    Date of Patent: September 14, 2021
    Assignee: Cirrus Logic, Inc.
    Inventor: John P. Lesso
  • Patent number: 11114108
    Abstract: A method includes extracting, from multiple microphone input, a hyperset of features of acoustic sources, using the extracted features to identify separable clusters associated with acoustic scenarios, and classifying subsequent input as one of the acoustic scenarios using the hyperset of features. The acoustic scenarios include a desired spatially moving/non-moving talker, and an undesired spatially moving/non-moving acoustic source. The hyperset of features includes both spatial and voice biometric features. The classified acoustic scenario may be used in a robotics application or voice assistant device desired speech enhancement or interference signal cancellation. Specifically, the classification of the acoustic scenarios can be used to adapt a beamformer, e.g., step size adjustment. The hyperset of features may also include visual biometric features extracted from one or more cameras viewing the acoustic sources.
    Type: Grant
    Filed: May 11, 2020
    Date of Patent: September 7, 2021
    Assignee: Cirrus Logic, Inc.
    Inventors: Ghassan Maalouli, Samuel P. Ebenezer
  • Patent number: 11112481
    Abstract: An apparatus for calibrating a differential circuit that includes a differential integrator having an input, a gain, and an output connected to a comparator. The differential integrator output is chargeable to a threshold prior to an integration period. The differential integrator integrates the input during the integration period such that the differential integrator output goes toward zero from the threshold. The comparator detects the output of the differential integrator reaching zero. The apparatus includes a closed-loop gain trim circuit to perform a coarse calibration to adjust and set the gain of the differential integrator and a reference generator that generates the threshold to which the differential integrator output is pre-charged. The reference generator is trimmable during a fine calibration to adjust and set the threshold to correct for residual gain error in the differential circuit remaining after the coarse calibration is performed.
    Type: Grant
    Filed: May 21, 2019
    Date of Patent: September 7, 2021
    Assignee: Cirrus Logic, Inc.
    Inventors: Sarang Vadnerkar, Vinod Jayakumar
  • Patent number: 11115046
    Abstract: A system may include an output stage for driving a load at an output of the output stage, a pulse-width modulation mode path configured to pre-drive the output stage in a first mode of operation, a linear mode path configured to pre-drive the output stage in a second mode of operation and a loop filter coupled at its input to the output of the output stage and coupled at its output to both of the pulse-width modulation mode path and the linear mode path. The pulse-width modulation mode path and the linear mode path may be configured such that a first transfer function between the output of the loop filter and the output of the output stage is substantially equivalent to a second transfer function between the output of the loop filter and the output of the output stage.
    Type: Grant
    Filed: June 4, 2019
    Date of Patent: September 7, 2021
    Assignee: Cirrus Logic, Inc.
    Inventors: Vamsikrishna Parupalli, Mark May, Saurabh Singh, Ramya Balasundaram, Mengde Wang, Eric B. Smith
  • Patent number: 11115775
    Abstract: An acoustic crosstalk canceller is determined for an asymmetric audio playback device, by determining a transfer function of an acoustic stereo playback path having asymmetries defined by speakers of the playback device. The transfer function is inverted to determine an inverse transfer function. The inverse transfer function is regularised by applying frequency dependent regularisation parameters to obtain an acoustic crosstalk canceller. Also, the inverse transfer function could be regularised for symmetric playback paths by applying aggregated frequency dependent regularisation parameters to obtain an acoustic crosstalk canceller without band branching.
    Type: Grant
    Filed: February 20, 2020
    Date of Patent: September 7, 2021
    Assignee: Cirrus Logic, Inc.
    Inventor: Vitaliy Sapozhnykov
  • Patent number: 11109155
    Abstract: A bass enhancement may be applied to improve the perception of low-frequency sounds by a user of an electronic device. A distortion function may be applied to the audio signal that results in creation of higher frequency content related to the low-frequency sounds. This higher frequency content may be interpreted by a listener's ear in a similar manner as the low-frequency sounds. The distortion function may be a Sigmoid function. Bass enhancements may also include scaling of the audio signal prior to distortion, adaptation of the distortion, or gap band filtering prior to the distortion.
    Type: Grant
    Filed: February 17, 2017
    Date of Patent: August 31, 2021
    Assignee: Cirrus Logic, Inc.
    Inventor: Eric Lindemann
  • Patent number: 11107493
    Abstract: An audio processing system is described for an audio event detection (AED) system. The system includes a feature extraction block configured to derive at least one feature which represents a spectral feature of the input signal.
    Type: Grant
    Filed: September 10, 2019
    Date of Patent: August 31, 2021
    Assignee: Cirrus Logic, Inc.
    Inventors: Sara Mainiero, Toby Stokes, Pablo Peso Parada, Rahim Saeidi
  • Patent number: 11107485
    Abstract: A single-bit audio stream can be converted to a modified single-bit audio stream with a constant edge rate while maintaining a modulation index of the original audio stream using direct mapping. With direct mapping, a pre-filter bank may be combined with a multi-bit symbol mapper to select symbols for the modified audio stream with a constant edge rate per symbol and the same modulation index as the original audio stream. The output of the pre-filter bank may be an audio stream with no consecutive full-scale symbols. Using the output of the pre-filter bank, a multi-bit symbol mapper may use the symbol selector to output a symbol with a constant edge rate per symbol and the same modulation index as the original signal. The symbols may be converted to an analog signal for reproduction of audio content using a transducer.
    Type: Grant
    Filed: August 2, 2019
    Date of Patent: August 31, 2021
    Assignee: Cirrus Logic, Inc.
    Inventors: Shafagh Kamkar, Dylan A. Hester, Bruce E. Duewer
  • Patent number: 11102583
    Abstract: An audio power output circuit provides a pair of output signals to an audio output transducer that has two different voice coils. Using a measured or predicted position of the voice coil assembly with respect to the transducer's magnetic field, a processing circuit generates the pair of signals such that a first relationship between a first one of the pair of output signals and an audio input signal and a second relationship between a second one of the pair of the output signals vary with the position of the voice coil. Offset in the Dynamic Mean Position (DMP) can be compensated for without adding low frequency or direct current components that compromise the dynamic range of the transducer. The efficiency, acoustic output power and/or linearity of the acoustic output of the transducer may be optimized by tailoring the first and second relationship to a particular target performance.
    Type: Grant
    Filed: March 25, 2020
    Date of Patent: August 24, 2021
    Assignee: CIRRUS LOGIC, INC.
    Inventors: Anthony S. Doy, Jeffrey A. May
  • Patent number: 11099949
    Abstract: A method and apparatus for programming a one-time programmable (OTP) memory device is disclosed that allows for resuming and recovering from an interrupted programming cycle (e.g. due to loss of power or user interaction). Upon re-initiation of a programming cycle with the same memory range, a programming controller may detect the memory address where interruption occurred, and resume programming from that address. If the programming interruption resulted in an incorrectly programmed word at the interrupted address, a word repair register may be mapped to the corrupted address to enable correction of that word. The remainder of the memory range may then be programmed normally.
    Type: Grant
    Filed: August 1, 2019
    Date of Patent: August 24, 2021
    Assignee: Cirrus Logic, Inc.
    Inventors: Michael A Kost, Bradley A Lambert, John P Tourish, Girish Subramaniam
  • Patent number: 11101778
    Abstract: The present disclosure relates to Class D amplifier circuitry comprising: an input for receiving an input signal; first and second output nodes for driving a load connected between the first and second output nodes. A first driver stage is provided for switching the first node between a first supply rail and a second supply rail, and a second driver stage is provided for switching the second node between the first supply rail and the second supply rail. The Class D amplifier circuitry also includes first driver control circuitry configured to receive a first carrier wave and control the switching of the first driver stage based in part on the first carrier wave; second driver control circuitry configured to receive a second carrier wave and control the switching of the second driver stage based in part on the second carrier wave; and a carrier wave generator configured to provide the first carrier wave and the second carrier wave.
    Type: Grant
    Filed: January 13, 2020
    Date of Patent: August 24, 2021
    Assignee: Cirrus Logic, Inc.
    Inventors: John Paul Lesso, Toru Ido
  • Patent number: 11093060
    Abstract: A system may include a resistive-inductive-capacitive sensor, a driver configured to drive the resistive-inductive-capacitive sensor at a driving frequency, a measurement circuit communicatively coupled to the resistive-inductive-capacitive sensor and configured to measure phase information and amplitude associated with the resistive-inductive-capacitive sensor, and a noise detection circuit communicatively coupled to the measurement circuit and configured to determine a presence of external interference in the system based on at least one of the phase information and the amplitude information.
    Type: Grant
    Filed: November 11, 2019
    Date of Patent: August 17, 2021
    Assignee: Cirrus Logic, Inc.
    Inventors: Gregory C. Yancey, Michael Kost, Tejasvi Das, Siddharth Maru, Matthew Beardsworth, Vadim Konradi
  • Patent number: 11092657
    Abstract: A system may include a resonant phase sensing system comprising a resistive-inductive-capacitive sensor and a measurement circuit communicatively coupled to the resistive-inductive-capacitive sensor, and a compensation circuit. The measurement circuit may be configured to use a phase detector to measure phase information associated with the resistive-inductive-capacitive sensor and based on the phase information, determine a displacement of a metal plate relative to the resistive-inductive-capacitive sensor. The compensation circuit may be configured to detect a change in a physical property associated with the resistive-inductive-capacitive sensor other than the displacement and compensate the phase information to correct for the change in the physical property.
    Type: Grant
    Filed: March 15, 2019
    Date of Patent: August 17, 2021
    Assignee: Cirrus Logic, Inc.
    Inventors: Siddharth Maru, Tejasvi Das, Zhong You
  • Patent number: 11089415
    Abstract: The disclosure relates in general to on-ear transition detection, and in particular to on-ear transition detection circuitry comprising: a monitoring unit operable to monitor a speaker current flowing through a speaker and/or a speaker voltage induced across the speaker, and to generate a monitor signal indicative of the speaker current and/or the speaker voltage; and an event detector operable to detect a qualifying disturbance in a sensor signal indicative of a qualifying pressure change incident on the speaker caused by the speaker transitioning from an on-ear state to an off-ear state or vice versa, wherein the sensor signal is, or is derived from, the monitor signal.
    Type: Grant
    Filed: March 25, 2020
    Date of Patent: August 10, 2021
    Assignee: Cirrus Logic, Inc.
    Inventor: John P. Lesso