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公开(公告)号：US10701486B1
公开(公告)日：2020-06-30
申请号：US16522439
申请日：2019-07-25
发明人： John L. Melanson , Xiaofan Fei , Lei Zhu , Xin Zhao , Wei-Shun Shum , Leyi Yin , Ku He , Johann G. Gaboriau
IPC分类号： H04R3/04
摘要： A system may include a filter configured to receive a digital audio input signal quantized at between two and 257 quantization levels and sampled at at least 500 kilohertz, the filter further configured to perform filtering on the digital audio input signal to generate a filtered digital audio input signal, the filter having a selectable variable group delay, 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.
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公开(公告)号：US10680640B2
公开(公告)日：2020-06-09
申请号：US15386213
申请日：2016-12-21
发明人： Cory J. Peterson , Anand Ilango
摘要： A digital-to-analog converter (DAC) for an audio system in a media device, such as a portable media device or smart phone, may be operated to turn off portions of the DAC to reduce power consumption. Segments of a segment-able DAC may be powered off when the output level of the DAC is lower than the full scale output of the DAC. For example, DAC elements within a finite impulse response (FIR) DAC may be turned off when a desired output level can be obtained with less than all DAC elements of the FIR DAC.
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公开(公告)号：US10658988B1
公开(公告)日：2020-05-19
申请号：US15943125
申请日：2018-04-02
发明人： Miao Song , Xiaofan Franky Fei , Xin Zhao , Tejasvi Das , Lei Zhu , Jing Bai , Alan Mark Morton
摘要： A signal processing system may include a modulation stage configured to generate a modulated input signal, an open-loop switched mode driver coupled to the modulation stage and configured to generate an output signal from the modulated input signal, a voltage regulator configured to generate a supply voltage that supplies electrical energy to the open-loop switched mode driver, and a control subsystem configured to, when a magnitude of the modulated input signal falls below a threshold magnitude, control the voltage regulator to control the supply voltage such that the output signal varies non-linearly with the modulated input signal for magnitudes of the modulated input signal below the threshold magnitude.
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公开(公告)号：US10651868B2
公开(公告)日：2020-05-12
申请号：US16233581
申请日：2018-12-27
发明人： Sri Ram Gupta
摘要： This application relates to modulators for providing time-encoded signals and in particular PWM signals. A modulator (200) has a first controlled oscillator (201P) configured to receive a first oscillator driving signal and output a first oscillation signal (S1). An accumulator (204) is configured to provide an accumulator value (VAL) based on a number of pulses of the first oscillation signal and a hysteretic comparator (205) alternates between first and second output states based on a hysteretic comparison of the accumulator value with a defined reference (REF). The first oscillator driving signal is based on a combination of an input signal and a feedback signal derived from an output of the hysteretic comparator. A second controlled oscillator (201N) may be configured to receive a second oscillator driving signal and output a second oscillation signal (S2) and the accumulator may provide the accumulator value based on a difference in the number of pulses of the first oscillation signal and the second oscillation signal.
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公开(公告)号：US10649015B1
公开(公告)日：2020-05-12
申请号：US15943154
申请日：2018-04-02
发明人： Vikrant Arumugam , Amar Vellanki , Vamsikrishna Parupalli , Zhong You , Johann G. Gaboriau , John L. Melanson
IPC分类号： G01R27/26
摘要： 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.
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公开(公告)号：US10599389B2
公开(公告)日：2020-03-24
申请号：US16202834
申请日：2018-11-28
摘要： A nonlinear control system and a speaker protection system are disclosed. In particular, a control system for adapting an audio output from a speaker in the proximity of an object is disclosed. The controller is configured to accept one or more input signals, and one or more estimated states produced by the model to produce one or more control signals. A speaker protection system and a quality control system are disclosed. More particularly, a system for clamping the input to a speaker dependent upon an estimate of the proximity, acoustic volume, and/or acoustic coupling of the speaker to a nearby object is disclosed.
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公开(公告)号：US10595150B2
公开(公告)日：2020-03-17
申请号：US15447944
申请日：2017-03-02
发明人： Vitaliy Sapozhnykov
摘要： 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.
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公开(公告)号：US10582309B2
公开(公告)日：2020-03-03
申请号：US16549625
申请日：2019-08-23
发明人： Hynek Saman , James Thomas Deas
摘要： This applications relates to methods and apparatus for amplifying signals from capacitive transducers, in particular MEMS transducers such as MEMS capacitive microphones. An amplifier circuit has a signal node for receiving the input signal, a transducer biasing node for outputting a transducer bias voltage for biasing the capacitive transducer, and a voltage buffer configured to generate a buffered bias voltage at a buffer node. An amplifier arrangement is configured to receive the input signal from the signal node and the buffered bias voltage. The amplifier circuit comprises a signal path for supplying the buffered bias voltage to the transducer biasing node via a first capacitance, and the amplifier arrangement comprises a feedback resistor network configured such that: a change in input signal with respect to the buffered bias voltage results in a change in the output signal with respect to the buffered bias voltage with a gain greater than one; and a change in the buffered bias voltage results in a change in the output signal with a gain equal to one.
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公开(公告)号：US10579119B2
公开(公告)日：2020-03-03
申请号：US15937152
申请日：2018-03-27
摘要： A method for port policy management for active charge through of a peripheral device that has a first communication port and a second communication port may include detecting whether a valid power connection exists at the peripheral device, in response to detecting the valid power connection, determining a relationship between the first communication port and the second communication port, based on the relationship, determining, by the peripheral device, a power relationship among the peripheral device, the first communication port, and the second communication port, selectively configuring the first communication port, the second communication port, and the peripheral device to match the power relationship, and enabling active charging through of the peripheral device if active charging through is supported by the power relationship.
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公开(公告)号：US10574256B1
公开(公告)日：2020-02-25
申请号：US16141555
申请日：2018-09-25
发明人： John Paul Lesso
摘要： This application relates to time-encoding modulators (TEMs). A TEM (100) receives an input signal (SIN) and outputs a time-encoded output signal (SOUT). A filter arrangement (102) 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 (101) 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 (103), capacitance (104) and switch network (105). In the first mode the op-amp (103) is enabled, and coupled with the capacitance (104) to provide the active filter. In the second mode the op-amp (103) is disabled and the capacitance coupled to a signal path for the feedback signal to provide a passive filter.
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