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公开(公告)号：US11277129B2
公开(公告)日：2022-03-15
申请号：US17314917
申请日：2021-05-07
Inventor： Axel Thomsen , Eric J. King , Anthony S. Doy , Thomas H. Hoff , John L. Melanson
IPC: H03B1/00 , H03K3/00 , H03K17/687 , H02N2/00 , H02M3/158
Abstract: This application relates to methods and apparatus for driving a transducer with switching drivers. A switching driver has first and second supply node for receiving supply voltages and includes an output bridge stage, a capacitor and a network of switches. The network of switches is operable in different switch states to provide different switching voltages to the output bridge stage. A controller is configured to control the switch state of the network of switches and a duty cycle of output switches of the output bridge stage based on an input signal to generate an output signal for driving the transducer.
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公开(公告)号：US11228840B2
公开(公告)日：2022-01-18
申请号：US16040853
申请日：2018-07-20
Inventor： Eric Lindemann , Itisha Tyagi , John L. Melanson
IPC: H04R7/04
Abstract: Embodiments described herein provide an audio device and a method of operating the audio device. The audio device comprises at least one surface, a first surface transducer positioned to excite first modes of oscillation in a first surface of the at least one surface, and a second surface transducer positioned to excite second modes of oscillation in a second surface of the at least one surface, wherein the first modes of oscillation are of a higher frequency than the second modes of oscillation.
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公开(公告)号：US20210249998A1
公开(公告)日：2021-08-12
申请号：US16786956
申请日：2020-02-10
Inventor： Vamsikrishna Parupalli , John L. Melanson
IPC: H03F1/34
Abstract: A dynamically stabilizable amplifier drives an output current into an RLC load. A driver stage generates the output current, and a control circuit compares a current level of the amplifier output with a threshold and selectively enables a stabilizing resistor (to selectively shunt the load or dampen in series with the load, depending on RLC load type) at the driver stage output based on the comparison so that the amplifier is stable across a range of the output current level. The control circuit disables the resistor when the output current is above the highest threshold and enables it when below. The control circuit may control the resistor to have one of multiple resistance values based on a comparison with multiple thresholds. The output current level may be determined by replicating the output current level or by an input current level that sets the output current level independent of the load.
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公开(公告)号：US11050433B1
公开(公告)日：2021-06-29
申请号：US16945520
申请日：2020-07-31
Inventor： John L. Melanson , Johann G. Gaboriau , Lei Zhu , Wai-Shun Shum , Xiaofan Fei , Leyi Yin
Abstract: A system may include a current digital-to-analog converter (IDAC) configured to convert a digital input signal into an output current signal and a switched-mode power supply configured to provide electrical energy in the form of a supply voltage to the IDAC for operation of the IDAC, the switched-mode power supply configured to track a voltage signal derived from the digital input current signal and generate the supply voltage based on the voltage signal and a voltage headroom above the voltage signal.
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15.发明授权公开(公告)号：US11043959B1
公开(公告)日：2021-06-22
申请号：US16942062
申请日：2020-07-29
Inventor： John L. Melanson , Johann G. Gaboriau , Lei Zhu , Wai-Shun Shum , Xiaofan Fei , Leyi Yin
Abstract: A differential output current digital-to-analog (IDAC) circuit may include a delta-sigma modulator configured to receive a digital input signal, a control circuit responsive to the delta-sigma modulator configured to perform a DAC decode operation, a plurality of DAC elements responsive to the DAC decode operation, the plurality of DAC elements configured to, in concert, generate a differential output current signal based on the digital input signal to a load coupled to a pair of output terminals of the IDAC, and a plurality of warming switches, each warming switch coupled to a respective bias transistor of a respective DAC element of the plurality of DAC elements, wherein the control circuit may further be configured to selectively control each such warming switch in order to selectively de-bias and bias a respective bias transistor of such warming switch when a respective DAC element of the respective bias transistor is output-disabled from generating the differential output current signal.
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Patent Agency Ranking
公开(公告)号：US10897268B2
公开(公告)日：2021-01-19
申请号：US16795045
申请日：2020-02-19
Inventor： Leyi YiN , John L. Melanson
Abstract: A system may include a modulator configured to generate a modulated data stream of samples from an input signal wherein each value of data in the modulated data stream when encoded is represented by a multi-bit code, wherein the modulator comprises a quantizer configured to quantize the modulated data stream from the input signal and feed back the modulated data stream as a feedback signal to an input of the modulator and a memory configured to store one or more samples of the modulated data stream. The system may also include an encoder configured to generate a synchronized serialized code stream from the modulated data stream. The quantizer may be configured to, based on the one or more samples of the modulated data stream stored in the memory, constrain the modulated data stream such that a synchronization state of the synchronized serialized code stream generated by the encoder is determinable based on the synchronized serialized code stream.
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公开(公告)号：US10828672B2
公开(公告)日：2020-11-10
申请号：US16369556
申请日：2019-03-29
Inventor： Carl Lennart Ståhl , Emmanuel Marchais , Anthony Stephen Doy , John L. Melanson
Abstract: Driver circuitry for driving an electromechanical load with a drive output signal based on a digital reference signal at a first sample rate, the drive output signal inducing a first electrical quantity at the electromechanical load, the driver circuitry comprising: a function block configured, based on said first electrical quantity, to digitally determine at a second sample rate higher than the first sample rate an adjustment signal indicative of a second electrical quantity which would be induced at a target output impedance of the driver circuitry due to said first electrical quantity; and a driver configured to generate the drive output signal based on the reference signal and the adjustment signal to cause the drive output signal to behave as if an output impedance of the driver circuitry has been adjusted to comprise the target output impedance, wherein the first electrical quantity is a current and the second electrical quantity is a voltage, or vice versa.
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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
Inventor： John L. Melanson , Xiaofan Fei , Lei Zhu , Xin Zhao , Wei-Shun Shum , Leyi Yin , Ku He , Johann G. Gaboriau
IPC: H04R3/04
Abstract: 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：US10649015B1
公开(公告)日：2020-05-12
申请号：US15943154
申请日：2018-04-02
Inventor： Vikrant Arumugam , Amar Vellanki , Vamsikrishna Parupalli , Zhong You , Johann G. Gaboriau , John L. Melanson
IPC: G01R27/26
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.
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公开(公告)号：US10181845B1
公开(公告)日：2019-01-15
申请号：US15927691
申请日：2018-03-21
Inventor： Tejasvi Das , Alan Mark Morton , Xin Zhao , Lei Zhu , Xiaofan Fei , Johann G. Gaboriau , John L. Melanson , Amar Vellanki
Abstract: A system may include a digital pulse width modulator subsystem, a first path coupled to an output of the digital pulse width modulator subsystem and configured to drive an open-loop driver stage, a second path coupled to the output of the digital pulse width modulator subsystem and configured to drive a closed-loop analog pulse width modulator, a controller to select between the first path and the second path for processing a signal based on one or more characteristics of the signal, and a calibration subsystem configured to calibrate at least one of a first gain of the first path and a second gain of the second path in order that the first gain and the second gain are at least approximately equal at the time of switching selection between the first path and the second path or vice versa, in order to minimize artifacts due to the switching.
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