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81.发明申请公开(公告)号：US20210044285A1
公开(公告)日：2021-02-11
申请号：US16996779
申请日：2020-08-18
Inventor： Ramin Zanbaghi , Anuradha Parsi , Kyehyung Lee , John L. Melanson
Abstract: A PWM modulator has a quantizer that generates a PWM output signal to speaker driver. When a first voltage swing range is supplied to the speaker driver, the quantizer analog gain is controlled to be a first gain value. When a second PWM drive voltage swing range is supplied to the speaker driver, the analog gain is controlled to be a second gain value. The first and second gain values of the analog gain of the quantizer cause the combined gain of the quantizer and driver to be approximately equal in the two modes. The quantizer has at least two gain-affecting measurable non-ideal characteristics. The quantizer is adjustable using measured first and second values to correct for first and second of the at least two non-ideal characteristics. The gain of the quantizer is calibratable while the quantizer is adjusted using the measured first and second measured values.
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公开(公告)号：US10819328B2
公开(公告)日：2020-10-27
申请号：US16163766
申请日：2018-10-18
Inventor： Ramin Zanbaghi , Anuradha Parsi , Kyehyung Lee , John L. Melanson
Abstract: A PWM modulator has a quantizer that generates a PWM output signal to speaker driver. When a first voltage swing range is supplied to the speaker driver, the quantizer analog gain is controlled to be a first gain value. When a second PWM drive voltage swing range is supplied to the speaker driver, the analog gain is controlled to be a second gain value. The first and second gain values of the analog gain of the quantizer cause the combined gain of the quantizer and driver to be approximately equal in the two modes. The quantizer has at least two gain-affecting measurable non-ideal characteristics. The quantizer is adjustable using measured first and second values to correct for first and second of the at least two non-ideal characteristics. The gain of the quantizer is calibratable while the quantizer is adjusted using the measured first and second measured values.
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公开(公告)号：US10764681B1
公开(公告)日：2020-09-01
申请号：US16522474
申请日：2019-07-25
Inventor： John L. Melanson
Abstract: A system may include an input configured to receive a digital audio input signal having at least four and fewer than 65,000 quantization levels and sampled at at least 500 kilohertz, a low-pass filter configured to receive the digital audio input signal and perform filtering on the digital audio input signal to generate a filtered digital audio input signal having a bandwidth of between approximately 100 hertz and 10 kilohertz, 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, wherein a group delay from the input to an output of the driver is less than 50 microseconds.
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公开(公告)号：US10763811B2
公开(公告)日：2020-09-01
申请号：US16181762
申请日：2018-11-06
Inventor： Lei Zhu , Tejasvi Das , John L. Melanson , Wai-shun Wilson Shum , Jing Bai , Xin Zhao , Xiaofan Fei
Abstract: A system may include a digital modulator configured to modulate an input signal received at an input of the digital modulator to generate a modulated input signal at an output of the digital modulator, a digital gain element having a digital gain and coupled to the digital modulator, an open-loop Class-D amplifier coupled to an output of the digital modulator and configured to amplify the modulated input signal, wherein the open-loop Class-D amplifier is powered from a variable power supply having a variable supply voltage which is variable in response to one or more characteristics of the input signal, and a control circuit configured to control the digital gain to approximately cancel changes in an analog gain of the open-loop Class-D amplifier due to variation in the variable supply voltage in response to the one or more characteristics of the input signal.
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公开(公告)号：US10681458B2
公开(公告)日：2020-06-09
申请号：US16004900
申请日：2018-06-11
Inventor： Pablo Peso Parada , Rahim Saeidi , John L. Melanson
IPC: H04R3/02 , H04M1/20 , G10K11/178
Abstract: A processing module for a noise control circuit may include a howling detector configured to receive an input signal and to determine a linearity metric based on the input signal, the linearity metric comprising a measure of the linearity of a logarithmic representation of the energy of the input signal. The processing module may also include a gain adjuster configured to adjust the gain of a noise control unit.
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Patent Agency Ranking
公开(公告)号：US10651800B2
公开(公告)日：2020-05-12
申请号：US15887644
申请日：2018-02-02
Inventor： Eric J. King , John L. Melanson
Abstract: A boosted amplifier system may include a boost stage configured to boost an input voltage of the boost stage to an output voltage greater than the input voltage and an amplifier stage powered by the output voltage of the charge pump and configured to amplify an input signal to generate an output signal. The boost stage may have input current limiting circuitry for ensuring that an input current of the boost stage is maintained below a current limit and the amplifier stage may have an input for receiving an indication of whether the current-limiting circuitry of the boost stage is activated to maintain the input current of the boost stage below the current limit.
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87.发明申请公开(公告)号：US20190199215A1
公开(公告)日：2019-06-27
申请号：US16226454
申请日：2018-12-19
Inventor： Xin Zhao , John L. Melanson , Eric King , Xiaofan Fei
CPC classification number: H02M3/1582 , G05F1/62 , H02M3/157
Abstract: The overall performance of single input multiple output (SIMO) switching DC-DC power converters may be improved by controlling power and output switches to adjust inductor current delivered to one output while maintaining substantially constant the current delivered to other outputs, thereby reducing cross regulation interference across outputs. Power converter systems of this disclosure may be configured to calculate an inductor current value and a duty cycle value based on voltages at each of the voltage outputs. The power converter systems may be configured to control at least one main power switch to increase or decrease the current in the inductor based on the calculated inductor current value. Additionally, the power converter systems may be configured to control at least one output power switch to divert current from the inductor to one of the plurality of output nodes based on the calculated duty cycle value.
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公开(公告)号：US20190149096A1
公开(公告)日：2019-05-16
申请号：US16249619
申请日：2019-01-16
Inventor： Lei Zhu , Xin Zhao , John L. Melanson
Abstract: Resistor mismatch may be digitally compensated based on a known resistor mismatch, power supply information, and/or other operating parameters of the amplifier. The digital compensation may be applied to the digital input signal before conversion for processing and amplification in the analog domain. An amplifier with digital compensation for resistor mismatch may be used in a class-D amplifier with a closed loop and feedforward feedback. A class-D or other amplifier with digital compensation may be integrated with electronic devices such as mobile phones.
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公开(公告)号：US10263584B1
公开(公告)日：2019-04-16
申请号：US16133045
申请日：2018-09-17
Inventor： Tejasvi Das , Alan Mark Morton , Xin Zhao , Lei Zhu , Xiaofan Fei , Johann G. Gaboriau , John L. Melanson , Amar Vellanki
IPC: H03G3/30 , H03F3/187 , H04R3/00 , H03K17/687
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, 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, wherein a first gain of the first path and a second gain of the second path are 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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公开(公告)号：US10224877B2
公开(公告)日：2019-03-05
申请号：US15581057
申请日：2017-04-28
Inventor： Lei Zhu , Xin Zhao , John L. Melanson
IPC: H03F3/38 , H03F1/02 , H03F1/56 , H03F3/183 , H03F3/217 , H03G3/30 , H03F1/30 , H03F1/32 , H03F3/187 , H03M1/66
Abstract: Resistor mismatch may be digitally compensated based on a known resistor mismatch, power supply information, and/or other operating parameters of the amplifier. The digital compensation may be applied to the digital input signal before conversion for processing and amplification in the analog domain. An amplifier with digital compensation for resistor mismatch may be used in a class-D amplifier with a closed loop and feedforward feedback. A class-D or other amplifier with digital compensation may be integrated with electronic devices such as mobile phones.
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