Patents by Inventor KWANG M. YI

KWANG M. YI 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).

  • Patent number: 9653982
    Abstract: Aspects include a power supply system. The system includes an oscillator system configured to generate a clock signal at a clock node. The oscillator system includes a comparator configured to compare a first variable voltage at a first comparator node and a second variable voltage at a second comparator node. The first and second variable voltages can have respective magnitudes that are based on a state of the clock signal. The system also includes a pulse-width modulation (PWM) generator configured to generate a PWM signal based on an error voltage and the clock signal. The system further includes a power stage configured to generate an output voltage based on the PWM signal.
    Type: Grant
    Filed: October 17, 2014
    Date of Patent: May 16, 2017
    Assignee: Northrop Grumman Systems Corporation
    Inventors: F. Dong Tan, Kwang M. Yi
  • Patent number: 9413220
    Abstract: One aspect includes power supply systems. The system includes an error amplifier system configured to generate an error voltage based on a feedback voltage of the power supply system relative to a reference voltage. The system also includes a PWM generator comprising a comparator configured to generate a PWM signal based on the error voltage and a ramp signal. The system further includes a power stage configured to generate the output voltage based on the PWM signal, the power stage comprising a transconductance amplifier configured to generate a temperature-compensated sense current associated with a magnitude of an output current associated with power stage. The ramp signal being generated based on the temperature-compensated sense current.
    Type: Grant
    Filed: October 17, 2014
    Date of Patent: August 9, 2016
    Assignee: Northrop Grumman Systems Corporation
    Inventors: F. Dong Tan, Kwang M. Yi
  • Patent number: 9281749
    Abstract: Aspects of the present invention include a power supply system comprising a plurality of power supplies. Each of the power supplies can include an oscillator system configured to generate a clock signal at a clock node. Each of the power supplies can include an error amplifier configured to generate an error voltage at an error amplifier output node. Each of the power supplies can also include a pulse-width modulation (PWM) generator configured to generate a PWM switching signal based on an error voltage and the clock signal. Each of the power supplies can further include a power stage configured to generate an output voltage based on the PWM switching signal.
    Type: Grant
    Filed: August 13, 2012
    Date of Patent: March 8, 2016
    Assignee: Northrop Grumman Systems Corporation
    Inventors: F. Dong Tan, Kwang M. Yi
  • Patent number: 9143028
    Abstract: One example of generating a clock signal via an oscillator system includes increasing a first comparison voltage at a first comparison node from a first magnitude to a second magnitude in response to a clock signal. A second comparison voltage is increased at a second comparison node from the first magnitude to the second magnitude in response to the clock signal. The clock signal changes state in response to the second comparison voltage increasing to a magnitude that is greater than the first comparison voltage. The first comparison voltage decreases from the second magnitude to the first magnitude in response to the clock signal. The second comparison voltage decreases from the second magnitude to the first magnitude in response to the clock signal. The clock signal changes state in response to the second comparison voltage decreasing to a magnitude that is less than the first comparison voltage.
    Type: Grant
    Filed: October 17, 2014
    Date of Patent: September 22, 2015
    Assignee: NORTHROP GRUMMAN SYSTEMS CORPORATION
    Inventors: F. Dong Tan, Kwang M. Yi
  • Publication number: 20150069987
    Abstract: One example of generating a clock signal via an oscillator system includes increasing a first comparison voltage at a first comparison node from a first magnitude to a second magnitude in response to a clock signal. A second comparison voltage is increased at a second comparison node from the first magnitude to the second magnitude in response to the clock signal. The clock signal changes state in response to the second comparison voltage increasing to a magnitude that is greater than the first comparison voltage. The first comparison voltage decreases from the second magnitude to the first magnitude in response to the clock signal. The second comparison voltage decreases from the second magnitude to the first magnitude in response to the clock signal. The clock signal changes state in response to the second comparison voltage decreasing to a magnitude that is less than the first comparison voltage.
    Type: Application
    Filed: October 17, 2014
    Publication date: March 12, 2015
    Applicant: NORTHROP GRUMMAN SYSTEMS CORPORATION
    Inventors: F. Dong Tan, Kwang M. Yi
  • Publication number: 20150035503
    Abstract: One aspect includes power supply systems. The system includes an error amplifier system configured to generate an error voltage based on a feedback voltage of the power supply system relative to a reference voltage. The system also includes a PWM generator comprising a comparator configured to generate a PWM signal based on the error voltage and a ramp signal. The system further includes a power stage configured to generate the output voltage based on the PWM signal, the power stage comprising a transconductance amplifier configured to generate a temperature-compensated sense current associated with a magnitude of an output current associated with power stage. The ramp signal being generated based on the temperature-compensated sense current.
    Type: Application
    Filed: October 17, 2014
    Publication date: February 5, 2015
    Applicant: NORTHROP GRUMMAN SYSTEMS CORPORATION
    Inventors: F. DONG TAN, Kwang M. Yi
  • Publication number: 20150035502
    Abstract: Aspects include a power supply system. The system includes an oscillator system configured to generate a clock signal at a clock node. The oscillator system includes a comparator configured to compare a first variable voltage at a first comparator node and a second variable voltage at a second comparator node. The first and second variable voltages can have respective magnitudes that are based on a state of the clock signal. The system also includes a pulse-width modulation (PWM) generator configured to generate a PWM signal based on an error voltage and the clock signal. The system further includes a power stage configured to generate an output voltage based on the PWM signal.
    Type: Application
    Filed: October 17, 2014
    Publication date: February 5, 2015
    Applicant: NORTHROP GRUMMAN SYSTEMS CORPORATION
    Inventors: F. Dong TAN, Kwang M. YI
  • Patent number: 8937468
    Abstract: Aspects include power supply systems. An error amplifier can generate an error voltage based on feedback associated with an output voltage to a reference voltage. A PWM generator can generate a PWM signal based on the error voltage. A power stage can generate the output voltage based on the PWM signal. The power stage can include a transconductance amplifier that generates a temperature-compensated sense current associated with a magnitude of an output current. An output voltage tuning circuit sets a desired magnitude of the output voltage based on at least one digital signal to adjust the reference voltage and the feedback voltage. An oscillator system generates a clock signal based on repeatedly charging and discharging a capacitor based on the clock signal and a comparator that compares the capacitor voltage and a second voltage having a magnitude that changes based on the state of the clock signal.
    Type: Grant
    Filed: August 13, 2012
    Date of Patent: January 20, 2015
    Assignee: Northrop Grumman Systems Corporation
    Inventors: F. Dong Tan, Kwang M. Yi
  • Publication number: 20140043006
    Abstract: Aspects include power supply systems. An error amplifier can generate an error voltage based on feedback associated with an output voltage to a reference voltage. A PWM generator can generate a PWM signal based on the error voltage. A power stage can generate the output voltage based on the PWM signal. The power stage can include a transconductance amplifier that generates a temperature-compensated sense current associated with a magnitude of an output current. An output voltage tuning circuit sets a desired magnitude of the output voltage based on at least one digital signal to adjust the reference voltage and the feedback voltage. An oscillator system generates a clock signal based on repeatedly charging and discharging a capacitor based on the clock signal and a comparator that compares the capacitor voltage and a second voltage having a magnitude that changes based on the state of the clock signal.
    Type: Application
    Filed: August 13, 2012
    Publication date: February 13, 2014
    Applicant: NORTHROP GRUMMAN SYSTEMS CORPORATION
    Inventors: F. DONG TAN, Kwang M. Yi
  • Publication number: 20140042812
    Abstract: Aspects of the present invention include a power supply system comprising a plurality of power supplies. Each of the power supplies can include an oscillator system configured to generate a clock signal at a clock node. Each of the power supplies can include an error amplifier configured to generate an error voltage at an error amplifier output node. Each of the power supplies can also include a pulse-width modulation (PWM) generator configured to generate a PWM switching signal based on an error voltage and the clock signal. Each of the power supplies can further include a power stage configured to generate an output voltage based on the PWM switching signal.
    Type: Application
    Filed: August 13, 2012
    Publication date: February 13, 2014
    Applicant: NORTHROP GRUMMAN SYSTEMS CORPORATION
    Inventors: F. DONG TAN, KWANG M. YI