Patents by Inventor Ru Feng Du

Ru Feng Du 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).

  • Publication number: 20240056046
    Abstract: An audio amplifier includes: a buck controller configured to control an output voltage at a first supply terminal, the output voltage selected from a set including a plurality of output voltages, where the output voltage takes a settling time to settle; a first audio bridge including: a class-AB driver stage coupled to the first supply terminal, and a delay insertion circuit configured to receive a processed digital stream and provide the processed digital stream to the class-AB driver stage a delay time after receiving the processed digital stream, where the delay time is based on the settling time; and an audio amplitude detector configured to detect a first peak amplitude in the first digital audio stream, where the buck controller is configured to select a lowest output voltage from the set that is higher than the first peak amplitude plus a headroom voltage.
    Type: Application
    Filed: October 24, 2023
    Publication date: February 15, 2024
    Inventors: XiangSheng Li, Ru Feng Du
  • Patent number: 11831286
    Abstract: An audio amplifier includes: a buck controller configured to control an output voltage at a first supply terminal, the output voltage selected from a set including a plurality of output voltages, where the output voltage takes a settling time to settle; a first audio bridge including: a class-AB driver stage coupled to the first supply terminal, and a delay insertion circuit configured to receive a processed digital stream and provide the processed digital stream to the class-AB driver stage a delay time after receiving the processed digital stream, where the delay time is based on the settling time; and an audio amplitude detector configured to detect a first peak amplitude in the first digital audio stream, where the buck controller is configured to select a lowest output voltage from the set that is higher than the first peak amplitude plus a headroom voltage.
    Type: Grant
    Filed: April 27, 2021
    Date of Patent: November 28, 2023
    Assignee: STMicroelectronics (Shenzhen) R&D Co. Ltd.
    Inventors: XiangSheng Li, Ru Feng Du
  • Patent number: 11750163
    Abstract: In an embodiment, a class-D amplifier includes an input terminal configured to receive an input signal; a comparator having an input coupled to the input terminal; a deglitching circuit having an input coupled to an output of the comparator; and a driving circuit having an input coupled to an output of the deglitching circuit. The deglitching circuit includes a logic circuit coupled between the input of the deglitching circuit and the output of the deglitching circuit. The logic circuit is configured to receive a clock signal having the same frequency as the switching frequency of the class-D amplifier.
    Type: Grant
    Filed: March 12, 2021
    Date of Patent: September 5, 2023
    Assignee: STMicroelectronics (Shenzhen) R&D Co. Ltd.
    Inventors: Ru Feng Du, Qi Yu Liu
  • Publication number: 20210250010
    Abstract: An audio amplifier includes: a buck controller configured to control an output voltage at a first supply terminal, the output voltage selected from a set including a plurality of output voltages, where the output voltage takes a settling time to settle; a first audio bridge including: a class-AB driver stage coupled to the first supply terminal, and a delay insertion circuit configured to receive a processed digital stream and provide the processed digital stream to the class-AB driver stage a delay time after receiving the processed digital stream, where the delay time is based on the settling time; and an audio amplitude detector configured to detect a first peak amplitude in the first digital audio stream, where the buck controller is configured to select a lowest output voltage from the set that is higher than the first peak amplitude plus a headroom voltage.
    Type: Application
    Filed: April 27, 2021
    Publication date: August 12, 2021
    Inventors: XiangSheng Li, Ru Feng Du
  • Publication number: 20210203293
    Abstract: In an embodiment, a class-D amplifier includes an input terminal configured to receive an input signal; a comparator having an input coupled to the input terminal; a deglitching circuit having an input coupled to an output of the comparator; and a driving circuit having an input coupled to an output of the deglitching circuit. The deglitching circuit includes a logic circuit coupled between the input of the deglitching circuit and the output of the deglitching circuit. The logic circuit is configured to receive a clock signal having the same frequency as the switching frequency of the class-D amplifier.
    Type: Application
    Filed: March 12, 2021
    Publication date: July 1, 2021
    Inventors: Ru Feng Du, Qi Yu Liu
  • Patent number: 11018644
    Abstract: An audio amplifier includes: a buck controller configured to control an output voltage at a first supply terminal, the output voltage selected from a set including a plurality of output voltages, where the output voltage takes a settling time to settle; a first audio bridge including: a class-AB driver stage coupled to the first supply terminal, and a delay insertion circuit configured to receive a processed digital stream and provide the processed digital stream to the class-AB driver stage a delay time after receiving the processed digital stream, where the delay time is based on the settling time; and an audio amplitude detector configured to detect a first peak amplitude in the first digital audio stream, where the buck controller is configured to select a lowest output voltage from the set that is higher than the first peak amplitude plus a headroom voltage.
    Type: Grant
    Filed: November 25, 2019
    Date of Patent: May 25, 2021
    Assignee: STMicroelectronics (Shenzen) R&D Co. Ltd.
    Inventors: XiangSheng Li, Ru Feng Du
  • Patent number: 10965263
    Abstract: In an embodiment, a class-D amplifier includes an input terminal configured to receive an input signal; a comparator having an input coupled to the input terminal; a deglitching circuit having an input coupled to an output of the comparator; and a driving circuit having an input coupled to an output of the deglitching circuit. The deglitching circuit includes a logic circuit coupled between the input of the deglitching circuit and the output of the deglitching circuit. The logic circuit is configured to receive a clock signal having the same frequency as the switching frequency of the class-D amplifier.
    Type: Grant
    Filed: March 15, 2019
    Date of Patent: March 30, 2021
    Assignee: STMICROELECTRONICS (SHENZHEN) R&D CO. LTD.
    Inventors: Ru Feng Du, Qi Yu Liu
  • Patent number: 10944366
    Abstract: In an embodiment, a class-AB amplifier includes: an output stage that includes a pair of half-bridges configured to be coupled to a load; and a current sensing circuit coupled to a first half-bridge of the pair of half-bridges. The current sensing circuit includes a resistive element and is configured to sense a load current flowing through the load by: mirroring a current flowing through a first transistor of the first half-bridge to generate a mirrored current, flowing the mirrored current through the resistive element, and sensing the load current based on a voltage of the resistive element.
    Type: Grant
    Filed: March 4, 2019
    Date of Patent: March 9, 2021
    Assignee: STMICROELECTRONICS (SHENZHEN) R&D CO. LTD
    Inventors: Ru Feng Du, XiangSheng Li
  • Publication number: 20200295723
    Abstract: In an embodiment, a class-D amplifier includes an input terminal configured to receive an input signal; a comparator having an input coupled to the input terminal; a deglitching circuit having an input coupled to an output of the comparator; and a driving circuit having an input coupled to an output of the deglitching circuit. The deglitching circuit includes a logic circuit coupled between the input of the deglitching circuit and the output of the deglitching circuit. The logic circuit is configured to receive a clock signal having the same frequency as the switching frequency of the class-D amplifier.
    Type: Application
    Filed: March 15, 2019
    Publication date: September 17, 2020
    Inventors: Ru Feng Du, Qi Yu Liu
  • Publication number: 20200287507
    Abstract: In an embodiment, a class-AB amplifier includes: an output stage that includes a pair of half-bridges configured to be coupled to a load; and a current sensing circuit coupled to a first half-bridge of the pair of half-bridges. The current sensing circuit includes a resistive element and is configured to sense a load current flowing through the load by: mirroring a current flowing through a first transistor of the first half-bridge to generate a mirrored current, flowing the mirrored current through the resistive element, and sensing the load current based on a voltage of the resistive element.
    Type: Application
    Filed: March 4, 2019
    Publication date: September 10, 2020
    Inventors: Ru Feng Du, XiangSheng Li
  • Publication number: 20200169234
    Abstract: An audio amplifier includes: a buck controller configured to control an output voltage at a first supply terminal, the output voltage selected from a set including a plurality of output voltages, where the output voltage takes a settling time to settle; a first audio bridge including: a class-AB driver stage coupled to the first supply terminal, and a delay insertion circuit configured to receive a processed digital stream and provide the processed digital stream to the class-AB driver stage a delay time after receiving the processed digital stream, where the delay time is based on the settling time; and an audio amplitude detector configured to detect a first peak amplitude in the first digital audio stream, where the buck controller is configured to select a lowest output voltage from the set that is higher than the first peak amplitude plus a headroom voltage.
    Type: Application
    Filed: November 25, 2019
    Publication date: May 28, 2020
    Inventors: XiangSheng Li, Ru Feng Du
  • Patent number: 10530309
    Abstract: A class D amplifier receives and amplifies a differential analog signal which is then differentially integrated. Two pulse width modulators generate pulse signals corresponding to the differentially integrated analog signal and two power units generate output pulse signals. The outputs the power units are coupled to input terminals of integrators via a resistor feedback network. An analog output unit converts the pulse signals to an output analog signal. The differential integration circuitry implements a soft transition between mute/un-mute. In mute, the integrator output is fixed. During the soft transition, the PWM outputs change slowly from a fixed 50% duty cycle to a final value to ensure that no pop noise is present in the output as a result of mode change.
    Type: Grant
    Filed: December 17, 2018
    Date of Patent: January 7, 2020
    Assignee: STMicroelectronics (Shenzhen) R&D Co. Ltd
    Inventors: Ru Feng Du, Qi Yu Liu
  • Publication number: 20190123694
    Abstract: A class D amplifier receives and amplifies a differential analog signal which is then differentially integrated. Two pulse width modulators generate pulse signals corresponding to the differentially integrated analog signal and two power units generate output pulse signals. The outputs the power units are coupled to input terminals of integrators via a resistor feedback network. An analog output unit converts the pulse signals to an output analog signal. The differential integration circuitry implements a soft transition between mute/un-mute. In mute, the integrator output is fixed. During the soft transition, the PWM outputs change slowly from a fixed 50% duty cycle to a final value to ensure that no pop noise is present in the output as a result of mode change.
    Type: Application
    Filed: December 17, 2018
    Publication date: April 25, 2019
    Applicant: STMicroelectronics (Shenzhen) R&D Co. Ltd
    Inventors: Ru Feng DU, Qi Yu LIU
  • Patent number: 10193506
    Abstract: A class D amplifier receives and amplifies a differential analog signal which is then differentially integrated. Two pulse width modulators generate pulse signals corresponding to the differentially integrated analog signal and two power units generate output pulse signals. The outputs the power units are coupled to input terminals of integrators via a resistor feedback network. An analog output unit converts the pulse signals to an output analog signal. The differential integration circuitry implements a soft transition between mute/un-mute. In mute, the integrator output is fixed. During the soft transition, the PWM outputs change slowly from a fixed 50% duty cycle to a final value to ensure that no pop noise is present in the output as a result of mode change.
    Type: Grant
    Filed: December 13, 2016
    Date of Patent: January 29, 2019
    Assignee: STMicroelectronics (Shenzhen) R&D Co. Ltd
    Inventors: Ru Feng Du, Qi Yu Liu
  • Patent number: 9667201
    Abstract: A class-D audio amplifier incorporates an overcurrent protection scheme implementing two overcurrent thresholds to avoid a dynamic impedance drop. When output current reaches the first threshold as a result of an impedance drop across the speaker, the overcurrent protection circuitry limits the output current to the value of the first threshold, but does not shut down the circuit. The second threshold is used to detect an overcurrent condition to shut down the circuit. Current limiting logic of a first channel monitors the overcurrent condition of a second channel and controls the first channel output in response thereto. This permits the second channel output current to reach the second threshold if the circuit is experiencing a short-circuit condition. This scheme also allows the output current to drop below the first threshold if the overcurrent condition of the second channel is caused by an impedance drop across the output speaker.
    Type: Grant
    Filed: January 21, 2016
    Date of Patent: May 30, 2017
    Assignee: STMicroelectronics (Shenzhen) R&D Co. Ltd
    Inventors: Ru Feng Du, Qi Yu Liu
  • Publication number: 20170093348
    Abstract: A class D amplifier receives and amplifies a differential analog signal which is then differentially integrated. Two pulse width modulators generate pulse signals corresponding to the differentially integrated analog signal and two power units generate output pulse signals. The outputs the power units are coupled to input terminals of integrators via a resistor feedback network. An analog output unit converts the pulse signals to an output analog signal. The differential integration circuitry implements a soft transition between mute/un-mute. In mute, the integrator output is fixed. During the soft transition, the PWM outputs change slowly from a fixed 50% duty cycle to a final value to ensure that no pop noise is present in the output as a result of mode change.
    Type: Application
    Filed: December 13, 2016
    Publication date: March 30, 2017
    Applicant: STMicroelectronics (Shenzhen) R&D Co. Ltd
    Inventors: Ru Feng Du, Qi Yu Liu
  • Patent number: 9577579
    Abstract: A class D amplifier receives and amplifies a differential analog signal which is then differentially integrated. Two pulse width modulators generate pulse signals corresponding to the differentially integrated analog signal and two power units generate output pulse signals. The outputs the power units are coupled to input terminals of integrators via a resistor feedback network. An analog output unit converts the pulse signals to an output analog signal. The differential integration circuitry implements a soft transition between mute/un-mute. In mute, the integrator output is fixed. During the soft transition, the PWM outputs change slowly from a fixed 50% duty cycle to a final value to ensure that no pop noise is present in the output as a result of mode change.
    Type: Grant
    Filed: March 1, 2016
    Date of Patent: February 21, 2017
    Assignee: STMicroelectronics (Shenzhen) R&D Co. Ltd
    Inventors: Ru Feng Du, Qi Yu Liu
  • Publication number: 20160181988
    Abstract: A class D amplifier receives and amplifies a differential analog signal which is then differentially integrated. Two pulse width modulators generate pulse signals corresponding to the differentially integrated analog signal and two power units generate output pulse signals. The outputs the power units are coupled to input terminals of integrators via a resistor feedback network. An analog output unit converts the pulse signals to an output analog signal. The differential integration circuitry implements a soft transition between mute/un-mute. In mute, the integrator output is fixed. During the soft transition, the PWM outputs change slowly from a fixed 50% duty cycle to a final value to ensure that no pop noise is present in the output as a result of mode change.
    Type: Application
    Filed: March 1, 2016
    Publication date: June 23, 2016
    Applicant: STMicroelectronics (Shenzhen) R&D Co. Ltd
    Inventors: Ru Feng Du, Qi Yu Liu
  • Publication number: 20160142024
    Abstract: A class-D audio amplifier incorporates an overcurrent protection scheme implementing two overcurrent thresholds to avoid a dynamic impedance drop. When output current reaches the first threshold as a result of an impedance drop across the speaker, the overcurrent protection circuitry limits the output current to the value of the first threshold, but does not shut down the circuit. The second threshold is used to detect an overcurrent condition to shut down the circuit. Current limiting logic of a first channel monitors the overcurrent condition of a second channel and controls the first channel output in response thereto. This permits the second channel output current to reach the second threshold if the circuit is experiencing a short-circuit condition. This scheme also allows the output current to drop below the first threshold if the overcurrent condition of the second channel is caused by an impedance drop across the output speaker.
    Type: Application
    Filed: January 21, 2016
    Publication date: May 19, 2016
    Applicant: STMicroelectronics (Shenzhen) R&D Co. Ltd
    Inventors: Ru Feng Du, Qi Yu Liu
  • Patent number: 9306523
    Abstract: A class D amplifier receives and amplifies a differential analog signal which is then differentially integrated. Two pulse width modulators generate pulse signals corresponding to the differentially integrated analog signal and two power units generate output pulse signals. The outputs the power units are coupled to input terminals of integrators via a resistor feedback network. An analog output unit converts the pulse signals to an output analog signal. The differential integration circuitry implements a soft transition between mute/un-mute. In mute, the integrator output is fixed. During the soft transition, the PWM outputs change slowly from a fixed 50% duty cycle to a final value to ensure that no pop noise is present in the output as a result of mode change.
    Type: Grant
    Filed: September 5, 2014
    Date of Patent: April 5, 2016
    Assignee: STMicroelectronics (Shenzhen) R&D Co. Ltd
    Inventors: Ru Feng Du, Qi Yu Liu