公开(公告)号：US11165436B2

公开(公告)日：2021-11-02

申请号：US17025014

申请日：2020-09-18

Applicant: Cirrus Logic International Semiconductor Ltd.

Inventor： John Paul Lesso

IPC: H03M1/60 ,  H03M1/50 ,  H03H11/12 ,  H03K17/687 ,  H04L27/06 ,  G04F10/00 ,  H03K7/08 ,  H03K7/02

Abstract: This application relates to time-encoding modulators (TEMs). A TEM receives an input signal (SIN) and outputs a time-encoded output signal (SOUT). A filter arrangement receives the input signal and also a feedback signal (SFB) from the TEM output, and generates a filtered signal (SFIL) based, at least in part, on the feedback signal. A comparator receives the filtered signal and outputs a time-encoded signal (SPWM) based at least in part on the filtered signal. The time encoding modulator is operable in a first mode with the filter arrangement configured as an active filter and in a second mode with the filter arrangement configured as a passive filter. The filter arrangement may include an op-amp, capacitance and switch network. In the first mode the op-amp is enabled, and coupled with the capacitance to provide the active filter. In the second mode the op-amp is disabled and the capacitance is coupled to a signal path for the feedback signal to provide a passive filter.

公开(公告)号：US11134324B2

公开(公告)日：2021-09-28

申请号：US16684925

申请日：2019-11-15

Applicant: Cirrus Logic International Semiconductor Ltd.

Inventor： John Paul Lesso

IPC: H04R1/08 ,  H04R3/04 ,  G10L25/78 ,  H03M1/12 ,  G10L17/00

Abstract: There is described a switchable microphone device which may be switched between a digital output mode and an analog output mode. There is further described a system for use of such a device, which allows for the switching between analog and digital computing modes.

公开(公告)号：US11101778B2

公开(公告)日：2021-08-24

申请号：US16740800

申请日：2020-01-13

Applicant: Cirrus Logic International Semiconductor Ltd.

Inventor： John Paul Lesso ,  Toru Ido

IPC: H03F3/21 ,  H04R3/00 ,  H03F3/217 ,  H04R29/00 ,  H03F3/185

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. A phase shift between the first carrier wave and the second carrier wave is adjustable responsive to a mode control signal.

公开(公告)号：US11051117B2

公开(公告)日：2021-06-29

申请号：US16805428

申请日：2020-02-28

Applicant: Cirrus Logic International Semiconductor Ltd.

Inventor： John Paul Lesso

IPC: H04R29/00 ,  G10L25/78 ,  G10L25/51 ,  G10L17/00 ,  G06F21/32 ,  H04R3/04 ,  G10L25/60 ,  G10L25/18

Abstract: A method of determining whether a sound has been generated by a loudspeaker comprises receiving an audio signal representing at least a part of the sound. The audio signal is separated into different frequency bands. The signal content of different frequency bands are compared. Based on said comparison, frequency-based variations in signal content indicative of use of a loudspeaker are identified.

公开(公告)号：US11017252B2

公开(公告)日：2021-05-25

申请号：US16157634

申请日：2018-10-11

Applicant: Cirrus Logic International Semiconductor Ltd.

Inventor： John Paul Lesso

IPC: G06K9/00 ,  G10L17/00 ,  G01S15/88 ,  G01S7/539 ,  G01S15/58 ,  G01S7/52 ,  G06K9/22 ,  G10L25/51 ,  G10L25/03 ,  G10L25/66

Abstract: Detecting a replay attack on a voice biometrics system comprises: receiving a speech signal; generating an ultrasound signal; detecting a reflection of the generated ultrasound signal; detecting Doppler shifts in the reflection of the generated ultrasound signal; and identifying whether the received speech signal is indicative of the liveness of a speaker based on the detected Doppler shifts. Identifying whether the received speech signal is indicative of liveness based on the detected Doppler shifts comprises determining whether the detected Doppler shifts correspond to a speech articulation rate.

公开(公告)号：US11003751B2

公开(公告)日：2021-05-11

申请号：US16028907

申请日：2018-07-06

Applicant: Cirrus Logic International Semiconductor Ltd.

Inventor： John Paul Lesso

IPC: G06F21/00 ,  G06F21/32 ,  G10K11/178

Abstract: Embodiments of the disclosure relate to methods, apparatus and systems for biometric processes. The invention relates to initiating generation of an acoustic stimulus for application to a user's ear and extracting features for use in a biometric process from a measured response signal. The measured response signal may be used to derive one or more quality metrics and the quality metrics may be used to validate features extracted from the measured response. The quality metrics may be used to provide feedback to the user seeking to carry out the biometric process.

公开(公告)号：US10935439B2

公开(公告)日：2021-03-02

申请号：US16105484

申请日：2018-08-20

Applicant: Cirrus Logic International Semiconductor Ltd.

Inventor： John Paul Lesso ,  Gordon James Bates

IPC: G01K11/22 ,  G01K15/00 ,  G01K7/00 ,  G01K7/32

Abstract: This application relates to methods and apparatus for temperature monitoring for integrated circuits, and in particular to temperature monitoring using a locked-loop circuits, e.g. FLLs, PLLs or DLLs. According to embodiments a locked-loop circuit (200, 600) includes a controlled signal timing module (201, 601), wherein the timing properties of an output signal (SOUT, SFB) are dependent on a value of a control signal and on temperature. A controller (201, 601) compares a feedback signal (SFB) output from the timing module to a reference signal (SREF) and generates a control signal (SC) to maintain a desired timing relationship. A temperature monitor (202) monitors temperature based on the value of the control signal. For FLLs and PLLs the signal timing module may be a controlled oscillator (201).

公开(公告)号：US10863284B2

公开(公告)日：2020-12-08

申请号：US15830358

申请日：2017-12-04

Applicant: Cirrus Logic International Semiconductor Ltd.

Inventor： John Paul Lesso ,  Cedric Andrieu ,  Calum Cuthill

IPC: H04R23/00 ,  H04B1/04 ,  H04B11/00 ,  H04R3/04 ,  H03G3/20 ,  H03G3/00 ,  G01S7/52 ,  G01S7/524 ,  G01S15/10

Abstract: Driver circuitry is disclosed for driving an electroacoustic transducer to provide an output comprising both ultrasonic and audio signal components. The driver circuitry comprises an adjustment module configured to reduce the level of said ultrasonic component signal in response to an increase in an operational variable indicative of a level of said audio signal component, while also increasing the pulse duration, duty cycle, repetition frequency or frequency span or bandwidth of the ultrasonic component.

公开(公告)号：US10853464B2

公开(公告)日：2020-12-01

申请号：US16018795

申请日：2018-06-26

Applicant: Cirrus Logic International Semiconductor Ltd.

Inventor： John Paul Lesso

IPC: G06F21/32 ,  H04L9/32 ,  G10L25/03 ,  G10L17/02 ,  H04K1/00 ,  H04L29/06 ,  G06F21/55 ,  H04W12/12 ,  G01R33/00 ,  G10L15/24 ,  G10L17/26 ,  H04R3/00

Abstract: In order to detect a replay attack in a speaker recognition system, at least one feature is identified in a detected magnetic field. It is then determined whether the at least one identified feature of the detected magnetic field is indicative of playback of speech through a loudspeaker. If so, it is determined that a replay attack may have taken place.

公开(公告)号：US10819363B2

公开(公告)日：2020-10-27

申请号：US16581953

申请日：2019-09-25

Applicant: Cirrus Logic International Semiconductor Ltd.

Inventor： John Paul Lesso

IPC: H03M1/12 ,  H03M1/50 ,  H03H11/12 ,  H03K17/687 ,  H04L27/06 ,  G04F10/00 ,  H03K7/08 ,  H03K7/02

Abstract: This application relates to time-encoding modulators (TEMs). A TEM receives an input signal (SIN) and outputs a time-encoded output signal (SOUT). A filter arrangement receives the input signal and also a feedback signal (SFB) from the TEM output, and generates a filtered signal (SFIL) based, at least in part, on the feedback signal. A comparator receives the filtered signal and outputs a time-encoded signal (SPWM) based at least in part on the filtered signal. The time encoding modulator is operable in a first mode with the filter arrangement configured as an active filter and in a second mode with the filter arrangement configured as a passive filter. The filter arrangement may include an op-amp, capacitance and switch network. In the first mode the op-amp is enabled, and coupled with the capacitance to provide the active filter. In the second mode the op-amp is disabled and the capacitance coupled to a signal path for the feedback signal to provide a passive filter.