公开(公告)号：US10720888B2

公开(公告)日：2020-07-21

申请号：US15336995

申请日：2016-10-28

Applicant: Cirrus Logic, Inc.

Inventor： Ramin Zanbaghi ,  Aaron J. Brennan ,  John L. Melanson ,  Mikel Ash

IPC: H03F3/185 ,  H03F3/217 ,  H03K7/08 ,  H03F1/02 ,  H03F1/30

Abstract: An integrated circuit may have two signal paths: an open-loop modulator (which may comprise a digital-input Class-D amplifier) and a closed-loop modulator (which may comprise an analog-input Class-D amplifier). A control subsystem may be capable of selecting either of the open-loop modulator or the closed-loop modulator as a selected path based on one or more characteristics (e.g., signal magnitude) of an input audio signal. For example, for higher-magnitude signals, the closed-loop modulator may be selected while the open-loop modulator may be selected for lower-magnitude signals. In some instances, when the open-loop modulator is selected as the selected path, the closed-loop modulator may power off, which may reduce power consumption. In addition, one or more techniques may be applied to reduce or eliminate user-perceptible audio artifacts caused by switching between the open-loop modulator and the closed-loop modulator, and vice versa.

公开(公告)号：US10219071B2

公开(公告)日：2019-02-26

申请号：US14101955

申请日：2013-12-10

Applicant: Cirrus Logic, Inc.

Inventor： Jeffrey D. Alderson

IPC: H04R3/00 ,  G10K11/178

Abstract: A method may include adaptively generating an anti-noise signal from filtering a reference microphone signal with an adaptive filter in conformity with an error microphone signal and the reference microphone signal. The method may also include adjusting the response of the adaptive filter by combining injected noise with the reference microphone signal and receiving the injected noise by a copy of the adaptive filter so that the response of the copy is controlled by the adaptive filter adapting to cancel a combination of the ambient audio sounds and the injected noise and controlling the response of the adaptive filter with the coefficients adapted in the copy, whereby the injected noise is not present in the anti-noise signal and wherein each of a sample rate of the copy and a rate of adapting of the adaptive filter is significantly less than a sample rate of the adaptive filter.

公开(公告)号：US10181315B2

公开(公告)日：2019-01-15

申请号：US14304208

申请日：2014-06-13

Applicant: Cirrus Logic, Inc.

Inventor： Jeffrey D. Alderson ,  Jon D. Hendrix ,  Dayong Zhou

IPC: G10K11/178 ,  H04R1/10 ,  H04R3/00 ,  H04R5/033

Abstract: In accordance with the present disclosure, an adaptive noise cancellation system may include a controller. The controller may be configured to determine a degree of convergence of an adaptive coefficient control block for controlling an adaptive response of the adaptive noise cancellation system. The controller may enable adaptation of the adaptive coefficient control block if the degree of convergence of the adaptive response is below a particular threshold and disable adaptation of the adaptive coefficient control block if the degree of convergence of the adaptive response is above a particular threshold, such that when the adaptive noise cancellation system is adequately converged, the adaptive noise cancellation system may conserve power by disabling one or more of its components.

公开(公告)号：US10126351B2

公开(公告)日：2018-11-13

申请号：US14720304

申请日：2015-05-22

Applicant: Cirrus Logic, Inc.

Inventor： Martin Joseph Gabriel, III ,  Jason Hwang

IPC: G01R31/26 ,  G01R31/02 ,  G01R1/073 ,  G01R31/28

Abstract: Systems and methods for multi-site placement of singulated semiconductor devices are presented. The systems and methods for multi-site placement may facilitate multi-site testing of the singulated semiconductor devices. A method may include determining a quantity of singulated semiconductor devices to be arranged in a test configuration. The method may also include determining, using a data processing device, a test configuration in response to the quantity. In further embodiments, the method may include placing the singulated semiconductor devices in a test frame according to the test configuration.

公开(公告)号：US10013997B2

公开(公告)日：2018-07-03

申请号：US14938816

申请日：2015-11-11

Applicant: Cirrus Logic Inc.

Inventor： Erik Sherwood ,  Carl Grundstrom

IPC: G10L21/0232 ,  G10L21/0208 ,  G10L21/0216 ,  G10L25/84

CPC classification number: G10L21/0232 ,  G10L21/0208 ,  G10L25/84 ,  G10L2021/02165

Abstract: A method for adjusting a degree of filtering applied to an audio signal includes modeling a probability density function (PDF) of a fast Fourier transform (FFT) coefficient of a primary channel and reference channel of the audio signal; maximizing at least one of PDFs to provide a discriminative relevance difference (DRD) between a noise magnitude estimate of the reference channel and a noise magnitude estimate of the primary channel. The method further includes emphasizing the primary channel when the spectral magnitude of the primary channel is stronger than the spectral magnitude of the reference channel; and deemphasizing the primary channel when the spectral magnitude of the reference channel is stronger than the spectral magnitude of the primary channel. The emphasizing and deemphasizing includes computing a multiplicative rescaling factor and applying the multiplicative rescaling factor to a gain computed in a prior stage of a speech enhancement filter chain when there is a prior stage, and directly applying a gain when there is no prior stage.

公开(公告)号：US09955250B2

公开(公告)日：2018-04-24

申请号：US15202644

申请日：2016-07-06

Applicant: CIRRUS LOGIC, INC.

Inventor： Jon D. Hendrix ,  Jeffrey Alderson ,  Ali Abdollahzadeh Milani ,  Dayong Zhou ,  Yang Lu

IPC: G10K11/16 ,  H04R1/10 ,  G10K11/178 ,  H04R3/12 ,  H04R1/24 ,  H04R3/00

CPC classification number: H04R1/1083 ,  G10K11/178 ,  G10K2210/1081 ,  G10K2210/3019 ,  G10K2210/3028 ,  H04R1/24 ,  H04R3/005 ,  H04R3/12 ,  H04R2410/05 ,  H04R2460/01

Abstract: A personal audio device including multiple output transducers for reproducing different frequency bands of a source audio signal, includes an adaptive noise canceling (ANC) circuit that adaptively generates an anti-noise signal for each of the transducers from at least one microphone signal that measures the ambient audio to generate anti-noise signals. The anti-noise signals are generated by separate adaptive filters such that the anti-noise signals cause substantial cancelation of the ambient audio at their corresponding transducers. The use of separate adaptive filters provides low-latency operation, since a crossover is not needed to split the anti-noise into the appropriate frequency bands. The adaptive filters can be implemented or biased to generate anti-noise only in the frequency band corresponding to the particular adaptive filter. The anti-noise signals are combined with source audio of the appropriate frequency band to provide outputs for the corresponding transducers.

公开(公告)号：US09919913B2

公开(公告)日：2018-03-20

申请号：US14942824

申请日：2015-11-16

Applicant: Cirrus Logic, Inc.

Inventor： Shanjen Pan ,  Marc L. Tarabbia

IPC: B81C1/00 ,  H04R19/04 ,  B81B3/00 ,  H04R19/00

CPC classification number: B81B3/0086 ,  B81B2201/0257 ,  B81C1/00698 ,  H04R19/005 ,  H04R19/04 ,  H04R2307/025

Abstract: A fully depleted region may be used to reduce poly-to-substrate parasitic capacitance in an electronic device with poly-silicon layer. When the fully depleted region is located at least partially beneath the electronic device, an additional parasitic capacitance is formed between the fully depleted region and the substrate region. This additional parasitic capacitance is coupled in series with a first parasitic capacitance between a poly-silicon layer of the electronic device and the doped region. The series combination of the first parasitic capacitance and the additional parasitic capacitance results in an overall reduction of parasitic capacitance experience by an electronic device. The structure may include two doped regions on sides of the electronic device to form a fully depleted region based on lateral interaction of dopant in the doped regions and the substrate region.

公开(公告)号：US09912238B1

公开(公告)日：2018-03-06

申请号：US14182939

申请日：2014-02-18

Applicant: Cirrus Logic, Inc.

Inventor： Ullas Pazhayaveetil ,  Jeffrey May ,  Gautham D. Kamath ,  John Christopher Tucker ,  Christian Larsen

IPC: G05F1/00 ,  H02M3/158 ,  H02M3/156

CPC classification number: H02M3/158 ,  G01R21/06 ,  G01R27/2611 ,  G06F1/3203 ,  H02M3/156 ,  H03F3/187 ,  H03F3/2175 ,  H03G3/004

Abstract: During operation of a boost converter conditions may exist that result in a reverse current through the boost converter, such as when a load drop from the boost converter occurs. During the reverse current period, inductance value determinations made during a forward current period may be used to estimate a magnitude of the reverse current and this estimate used by a controller to control the boost converter and return the boost converter to normal operation. The controller may control the boost converter by changing a ratio of charging and discharging time for an inductor of the boost converter, decreasing a bandwidth of the boost converter, and/or increasing a resistance of the boost converter.

公开(公告)号：US20180048295A1

公开(公告)日：2018-02-15

申请号：US15790863

申请日：2017-10-23

Applicant: Cirrus Logic, Inc.

Inventor： John L. Melanson ,  Paul Lesso

IPC: H03K3/011

CPC classification number: H03K3/011 ,  H03F1/303 ,  H03F3/2171 ,  H03K7/08 ,  H03M1/822

Abstract: Noise introduced in an output signal of a pulse-width modulator (PWM) may be reduced by changing the time duration that a switch is driving the output node. Because the power supplies coupled to the switches are the source of noise in the output signal of the PWM, the time duration that the power supplies are driving the output may be reduced to obtain a subsequent reduction in noise in the output signal. For example, when a small signal is desired to be output by the PWM, the switches may be operated for shorter time durations. Thus, the switches couple the noise sources to ground for a duration of a cycle to reduce contribution of noise to the output. But, when a larger signal is desired to be output by the PWM, the switches may be operated for longer time durations or the conventional time durations described above.

公开(公告)号：US20180047412A1

公开(公告)日：2018-02-15

申请号：US15730152

申请日：2017-10-11

Applicant: Cirrus Logic, Inc.

Inventor： Jan S. Erkelens

IPC: G10L25/21 ,  G10L21/0232 ,  H04R29/00 ,  G10L25/12

CPC classification number: G10L25/21 ,  G10L21/0232 ,  G10L25/12 ,  G10L2021/02165 ,  H04R3/005 ,  H04R29/004 ,  H04R29/006 ,  H04R2410/05

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.