Patents Assigned to Cirrus Logic International Semiconductor Ltd.
  • Publication number: 20210288807
    Abstract: There is described a system and method for performing biometric authentication, preferably voice biometric authentication. The system has a host device such as a mobile phone and a coupled headset device. The headset device is arranged to receive audio, and to cryptographically protect the audio before transmission to the host device for verification and biometric authentication.
    Type: Application
    Filed: October 1, 2018
    Publication date: September 16, 2021
    Applicant: Cirrus Logic International Semiconductor Ltd.
    Inventors: Michael PAGE, John Paul LESSO
  • Publication number: 20210286393
    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: Application
    Filed: March 11, 2020
    Publication date: September 16, 2021
    Applicant: Cirrus Logic International Semiconductor Ltd.
    Inventors: Christopher M. DOUGHERTY, Anindya BHATTACHARYA, Vaibhav PANDEY, Ying OU
  • Publication number: 20210279317
    Abstract: Embodiments of the invention relate to methods, apparatus and systems for biometric processes. The methods include updating stored ear model data for a user following successful authentication of the user. The ear model data may be acquired using a personal audio device that generates an acoustic stimulus and detects a measured response. The acquisition of the ear model data may be responsive to a determination that the personal audio device is inserted into or placed adjacent to the user's ear. The acquisition of the ear model data may also be responsive to the determination that the personal audio device has not been removed from or moved away from the user's ear.
    Type: Application
    Filed: March 3, 2021
    Publication date: September 9, 2021
    Applicant: Cirrus Logic International Semiconductor Ltd.
    Inventor: John Paul LESSO
  • Publication number: 20210281270
    Abstract: An analog-to-digital conversion system may include an analog-to-digital converter configured to convert an analog input signal into an equivalent digital input signal, a first filtering path configured to filter the equivalent digital input signal to generate a first filtered digital signal, wherein the first filtering path comprises a zero-overshoot monotonic step response filter, a second filtering path configured to filter the equivalent digital input signal to generate a second filtered digital signal, wherein the second filtering path comprises a frequency-selective filter; and a mixer configured to either: (i) select between the first filtered digital signal and the second filtered digital signal in order to generate an output digital signal; or (ii) combine selected proportions of each of the first filtered digital signal and the second filtered digital signal in order to generate the output digital signal.
    Type: Application
    Filed: February 4, 2021
    Publication date: September 9, 2021
    Applicant: Cirrus Logic International Semiconductor Ltd.
    Inventors: Sunder S. KIDAMBI, Mohit SOOD
  • Publication number: 20210273646
    Abstract: This application relates to ADC circuitry. An ADC circuit (200) has first and second conversion paths (201a, 201b) for converting analogue signals to digital and is operable in first and second modes. In the first mode, the first and second conversion paths are connected to respective first and second input nodes (202a, 202b) to receive and convert full scale first and second analogue input signals (Ain1, Ain2) to separate digital outputs (Dout1, Dout2). In the second mode, the first and second conversion paths are both connected to the first input node (202a), to convert the first analogue input signal (Ain1) to respective first and second digital signals, and the first and second conversion paths are configured for processing different signal levels of the first analogue input signal. A selector (207) select the first digital signal or the second digital to be output as an output signal based on an indication of amplitude of the first analogue input signal.
    Type: Application
    Filed: February 24, 2021
    Publication date: September 2, 2021
    Applicant: Cirrus Logic International Semiconductor Ltd.
    Inventors: Andrew J. HOWLETT, David P. SINGLETON, Aniruddha SATOSKAR
  • Publication number: 20210264923
    Abstract: An audio system receives an audio signal from a digital microphone, which has an analog-digital converter with a controllable sampling rate. In response to a determination that a predetermined trigger phrase is not detected in the decimated audio signal, the sampling rate of the analog-digital converter in the digital microphone is controlled such that the audio signal has a first sample rate. In response to a determination that the predetermined trigger phrase is detected in the decimated signal, the sampling rate of the analog-digital converter in the digital microphone is controlled such that the audio signal has a second sample rate higher than the first sample rate, and the audio signal is applied to a spoof detection circuit, to determine whether the received signal contains live speech or replayed speech.
    Type: Application
    Filed: February 1, 2021
    Publication date: August 26, 2021
    Applicant: Cirrus Logic International Semiconductor Ltd.
    Inventor: John P. LESSO
  • Publication number: 20210256971
    Abstract: A method of detecting a replay attack comprises: receiving an audio signal representing speech; identifying speech content present in at least a portion of the audio signal; obtaining information about a frequency spectrum of each portion of the audio signal for which speech content is identified; and, for each portion of the audio signal for which speech content is identified: retrieving information about an expected frequency spectrum of the audio signal; comparing the frequency spectrum of portions of the audio signal for which speech content is identified with the respective expected frequency spectrum; and determining that the audio signal may result from a replay attack if a measure of a difference between the frequency spectrum of the portions of the audio signal for which speech content is identified and the respective expected frequency spectrum exceeds a threshold level.
    Type: Application
    Filed: July 31, 2019
    Publication date: August 19, 2021
    Applicant: Cirrus Logic International Semiconductor Ltd.
    Inventors: John Paul LESSO, César ALONSO, Earl Corban VICKERS
  • Publication number: 20210257405
    Abstract: There is described a two-terminal multi-level memristor element synthesised from binary memristors, which is configured to implement a variable resistance based on unary or binary code words. There is further described a circuit such as a synapse circuit implemented using a multi-level memristor element.
    Type: Application
    Filed: May 5, 2021
    Publication date: August 19, 2021
    Applicant: Cirrus Logic International Semiconductor Ltd.
    Inventor: John Paul LESSO
  • Publication number: 20210248403
    Abstract: Described embodiments relate to a method operable in a biometric authentication system. The method comprises initiating generation of an acoustic stimulus for application to a user's ear; and determining a quality measure of a response signal to the acoustic stimulus. Responsive to determining that the quality measure is inadequate for performing a biometric process, the method comprises one or more of: (i) modifying one or more properties of the acoustic stimulus to improve a signal to noise ratio, SNR, of the response signal and (ii) cancelling the effect of noise from outside the ear on the response signal of the user's ear to the acoustic stimulus to improve the SNR of the response signal.
    Type: Application
    Filed: February 23, 2021
    Publication date: August 12, 2021
    Applicant: Cirrus Logic International Semiconductor Ltd.
    Inventors: Thomas Ivan HARVEY, Vitaliy SAPOZHNYKOV, Brenton POTTER
  • Publication number: 20210250685
    Abstract: This application relates to driver circuitry (200) for receiving a digital input signal (D) and outputting, at first and second output nodes (203p, 203n), first and second analogue driving signals respectively for driving a transducer (101), e.g. loudspeaker, in a bridge-tied-load configuration. The driver circuitry may particularly be suitable for driving low-impedance transducers. The driver circuitry has first and second digital-to-analogue converters (201p, 201n) configured to receive the digital input signal and the outputs of the first and second digital-to-analogue converters are coupled to the first and second output nodes respectively. A differential-output amplifier circuit (202) has outputs connected to the first and second output nodes and is configured to regulate the outputs of the digital-to-analogue converters at output nodes to provide the analogue driving signals.
    Type: Application
    Filed: January 26, 2021
    Publication date: August 12, 2021
    Applicant: Cirrus Logic International Semiconductor Ltd.
    Inventors: Andrew J. HOWLETT, Sharjeel RIAZ, John P. LESSO
  • Publication number: 20210242847
    Abstract: The present disclosure relates to circuitry comprising audio amplifier circuitry for receiving an audio signal to be amplified; and first and second output nodes for outputting first and second differential output signals. The circuitry further comprises common mode buffer circuitry configured to receive a common mode voltage and to selectively output the common mode voltage to the first and second output nodes.
    Type: Application
    Filed: January 6, 2021
    Publication date: August 5, 2021
    Applicant: Cirrus Logic International Semiconductor Ltd.
    Inventors: David P. SINGLETON, Andrew J. HOWLETT, John B. BOWLERWELL
  • Publication number: 20210242865
    Abstract: Circuitry for controlling current between a load and a power supply, the circuitry comprising: an output stage comprising: an input node configured to be coupled to the power supply; and an output node configured to be coupled to the load; and one or more control nodes for controlling a conduction path between the input node and the output node; and protection circuitry coupled to the one or more control nodes, the protection circuitry configured to break the conduction path between the input node and the output node when a load voltage at the output node exceeds a supply voltage at the input node, wherein the protection circuitry comprises: an active protection circuit configured to break the conduction path when the supply voltage exceeds an operational threshold of the active protection circuit; and a passive protection circuit configured to break the conduction path when the supply voltage is below an operation threshold of the active protection circuit.
    Type: Application
    Filed: January 27, 2021
    Publication date: August 5, 2021
    Applicant: Cirrus Logic International Semiconductor Ltd.
    Inventors: Andrew BUIST, Mark MCCLOY-STEVENS, Dave SMITH, Gordon RUSSELL, Huy Binh LE
  • Publication number: 20210243531
    Abstract: A system for driving a transducer having a plurality of coils, the system comprising: a modulator for outputting a digital output signal representative of a received analogue input signal at a modulator output; a clock controlled delay element for applying a delay to the digital output signal to generate a first delayed signal at a delay element output; wherein the modulator output is couplable to a first coil of the plurality of the coils of the transducer and the delay element output is couplable to a second coil of the plurality of coils of the transducer.
    Type: Application
    Filed: January 29, 2021
    Publication date: August 5, 2021
    Applicant: Cirrus Logic International Semiconductor Ltd.
    Inventor: John P. LESSO
  • Publication number: 20210241747
    Abstract: Embodiments generally relate to a signal processing device for on ear detection for a headset. The device comprises a first microphone input for receiving a microphone signal from a first microphone, the first microphone being configured to be positioned inside an ear of a user when the user is wearing the headset; a second microphone input for receiving a microphone signal from a second microphone, the second microphone being configured to be positioned outside the ear of the user when the user is wearing the headset; and a processor.
    Type: Application
    Filed: January 30, 2020
    Publication date: August 5, 2021
    Applicant: Cirrus Logic International Semiconductor Ltd.
    Inventor: Brenton STEELE
  • Publication number: 20210232165
    Abstract: The present disclosure relates to circuitry for selecting a bias voltage to output at a bias voltage output node of the circuitry. The circuitry comprises a first circuit node configured to receive a first voltage from a first, unregulated, voltage source and a second circuit node configured to receive a second voltage from a second, regulated, voltage source. A switch arrangement configured to selectively couple the bias voltage output node to the first circuit node or the second circuit node is also provided.
    Type: Application
    Filed: January 4, 2021
    Publication date: July 29, 2021
    Applicant: Cirrus Logic International Semiconductor Ltd.
    Inventors: John B. BOWLERWELL, Andrew J. HOWLETT, Graeme S. ANGUS, Andrei DUMITRIU
  • Publication number: 20210225352
    Abstract: An integrated circuit for implementing at least a portion of a personal audio device may include an output for providing an output signal to a transducer, wherein the output signal includes a pilot signal, a microphone input for receiving a microphone signal from a microphone indicative of an output of the transducer, and a processing circuit. The processing circuit may be configured to implement a pilot signal control to apply an adjustment to the pilot signal as necessary to maintain the pilot signal at a substantially constant magnitude regardless of proximity of the transducer to a pinna and implement a proximity determination block configured to determine proximity of the transducer to the pinna based on the adjustment.
    Type: Application
    Filed: January 7, 2021
    Publication date: July 22, 2021
    Applicant: Cirrus Logic International Semiconductor Ltd.
    Inventors: Viral PARIKH, Jon D. HENDRIX, Jeffrey D. ALDERSON, Vitaliy SAPOZHNYKOV, Nafiseh Erfanian SAEEDI, Thomas I. HARVEY, Robert LUKE
  • Publication number: 20210219396
    Abstract: The present disclosure relates to current control circuitry for controlling a current through a load. The current control circuitry comprises amplifier circuitry, reference voltage generator circuitry configured to supply a fixed reference voltage to a first input of the amplifier circuitry and an output stage comprising: a control terminal coupled to an output of the amplifier circuitry; a current input terminal configured to be coupled to the load; and a current output terminal. The current control circuitry further comprises a variable resistance coupled to the current output terminal of the output stage, and a feedback path between the current output terminal of the output stage and a second terminal of the amplifier circuitry for providing a feedback voltage to a second input of the amplifier circuitry.
    Type: Application
    Filed: December 16, 2020
    Publication date: July 15, 2021
    Applicant: Cirrus Logic International Semiconductor Ltd.
    Inventors: Dave SMITH, Saurabh SINGH, Andrew BUIST, Paulius CEREBIEJUS, Mark J. MCCLOY-STEVENS, Terence A. ORR
  • Publication number: 20210219055
    Abstract: The application describes techniques for howling detection. A howling detector is described that is configured to receive an input signal and to determine measure of the linearity of a logarithmic representation of the energy of the input signal. In some examples, this triggers gain adjustment (e.g. of a noise control unit) and, in some further examples, the amount of the gain adjustment may be based on an estimation of the maximum stable gain of a noise control unit.
    Type: Application
    Filed: May 29, 2019
    Publication date: July 15, 2021
    Applicant: Cirrus Logic International Semiconductor Ltd.
    Inventors: Pablo PESO PARADA, Rahim SAEIDI, John L. MELANSON
  • Publication number: 20210200316
    Abstract: Embodiments described herein relate to methods and apparatuses for controlling an operation of a vibrational output system and/or an operation of an input sensor system, wherein the controller is for use in a device comprising the vibrational output system and the input sensor system. A controller comprises an input configured to receive an indication of activation or de-activation of an output of the vibrational output system; and an adjustment module configured to adjust the operation of the vibrational output system and/or the operation of the input sensor system based on the indication to reduce an interference expected to be caused by the output of the vibrational output system on the input sensory system.
    Type: Application
    Filed: March 3, 2021
    Publication date: July 1, 2021
    Applicant: Cirrus Logic International Semiconductor Ltd.
    Inventors: Tejasvi DAS, Matthew BEARDSWORTH, Michael A. KOST, Gavin MCVEIGH, Hamid SEPEHR, Carl L. STÅHL
  • Publication number: 20210192033
    Abstract: Detecting a replay attack on a voice biometrics system comprises receiving a speech signal; forming an autocorrelation of at least a part of the speech signal; and identifying that the received speech signal may result from a replay attack based on said autocorrelation. Identifying that the received speech signal may result from a replay attack may be achieved by: comparing the autocorrelation with a reference value; and identifying that the received speech signal may result from a replay attack based on a result of the comparison of the autocorrelation with the reference value, or by: supplying the autocorrelation to a neural network trained to distinguish autocorrelations formed from speech signals resulting from replay attacks from autocorrelations formed from speech signals not resulting from replay attacks.
    Type: Application
    Filed: March 5, 2021
    Publication date: June 24, 2021
    Applicant: Cirrus Logic International Semiconductor Ltd.
    Inventor: John Paul LESSO