Patents by Inventor Wai-shun Wilson SHUM

Wai-shun Wilson SHUM has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Gain control in a class-D open-loop amplifier
    Patent number: 10763811
    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.
    Type: Grant
    Filed: November 6, 2018
    Date of Patent: September 1, 2020
    Assignee: Cirrus Logic, Inc.
    Inventors: Lei Zhu, Tejasvi Das, John L. Melanson, Wai-shun Wilson Shum, Jing Bai, Xin Zhao, Xiaofan Fei
  • GAIN CONTROL IN A CLASS-D OPEN-LOOP AMPLIFIER
    Publication number: 20200036352
    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.
    Type: Application
    Filed: November 6, 2018
    Publication date: January 30, 2020
    Applicant: Cirrus Logic International Semiconductor Ltd.
    Inventors: Lei ZHU, Tejasvi DAS, John L. MELANSON, Wai-shun Wilson SHUM, Jing BAI, Xin ZHAO, Xiaofan FEI