Patents by Inventor Kuang-Yao Cheng

Kuang-Yao Cheng 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: 20140266112
    Abstract: One embodiment includes a power regulator system. The system includes a switch control stage configured to generate at least one activation signal based on a pulse-width modulation (PWM) signal and to control a respective at least one switch to generate an output voltage. The system also includes a feedback stage configured to generate the PWM signal based on a ramp signal and a feedback voltage that is based on the output voltage. The system further includes a ramp generator stage configured to adaptively generate the ramp signal based on the output voltage and based on the at least one activation signal.
    Type: Application
    Filed: May 31, 2013
    Publication date: September 18, 2014
    Inventors: KUANG-YAO CHENG, HAL CHEN, WENKAI WU, WEIDONG ZHU
  • Patent number: 8575911
    Abstract: Stabilization of a switching voltage regulator employing V2 control against ripple oscillation instability when the equivalent series resistance (ESR) of an output capacitor is small is provided by providing both an external ramp and an internal ramp (only the latter of which requires an approximation of inductor current) in the control feedback path, preferably including both inner and outer feedback loops. Approximation of inductor current using such an arrangement is non-critical and may be estimated based on power input voltage. Drift of a circuit providing such an inductor current estimation is preferably avoided by adjusting control duty cycle or slew rate of the positive-going ramp portion of the estimated inductor current triangular waveform.
    Type: Grant
    Filed: August 12, 2010
    Date of Patent: November 5, 2013
    Assignee: Virginia Tech Intellectual Properties, Inc.
    Inventors: Kuang-Yao Cheng, Feng Yu, Paolo Mattavelli, Fred C. Lee
  • Patent number: 8400086
    Abstract: An apparatus and method for use with a PMSM detect the fall time or the rise time and the fall time of a motor current in the PMSM under different voltage vectors when the PMSM is in start-up to determine an initial rotor position for the PMSM at standstill.
    Type: Grant
    Filed: January 19, 2010
    Date of Patent: March 19, 2013
    Assignee: Richtek Technology Corp.
    Inventor: Kuang-Yao Cheng
  • Publication number: 20110316508
    Abstract: Stabilization of a switching voltage regulator employing V2 control against ripple oscillation instability when the equivalent series resistance (ESR) of an output capacitor is small is provided by providing both an external ramp and an internal ramp (only the latter of which requires an approximation of inductor current) in the control feedback path, preferably including both inner and outer feedback loops. Approximation of inductor current using such an arrangement is non-critical and may be estimated based on power input voltage. Drift of a circuit providing such an inductor current estimation is preferably avoided by adjusting control duty cycle or slew rate of the positive-going ramp portion of the estimated inductor current triangular waveform.
    Type: Application
    Filed: August 12, 2010
    Publication date: December 29, 2011
    Inventors: Kuang-Yao Cheng, Feng Yu, Paolo Mattavelli, Fred C. Lee
  • Patent number: 8030911
    Abstract: A hybrid control circuit and method combine analog circuit and digital circuit to generate digital PWM signals for a multiphase DC-DC converter to generate an output voltage. For current balance control, analog current error signals are generated by the analog circuit from analog phase current signals of the multiphase DC-DC converter and then converted into digital current error signals for calculating the duties of each phase of the multiphase DC-DC converter. Therefore, fewer bit devices can be used to achieve precise current balance control and the size and cost of the circuit can be reduced.
    Type: Grant
    Filed: March 11, 2010
    Date of Patent: October 4, 2011
    Assignee: Richtek Technology Corp.
    Inventors: Hung-Shou Nien, Kuang-Yao Cheng, Yi-Chiang Fu, Wei-Hsu Chang
  • Patent number: 7898210
    Abstract: After an AC motor generates a three-phase current, modulate the three-phase current to generate an original voltage space vector, and add three detecting vectors with a sum of zero after the original voltage space vector. While adding the three detecting vectors, sample the current to generate a sampling result. Then adjust the width of pulses generated by a pulse width modulator according to the sampling result.
    Type: Grant
    Filed: August 15, 2008
    Date of Patent: March 1, 2011
    Assignee: Prolific Technology Inc.
    Inventors: Tung-Chin Hsieh, Kuang-Yao Cheng
  • Publication number: 20100238060
    Abstract: A hybrid control circuit and method combine analog circuit and digital circuit to generate digital PWM signals for a multiphase DC-DC converter to generate an output voltage. For current balance control, analog current error signals are generated by the analog circuit from analog phase current signals of the multiphase DC-DC converter and then converted into digital current error signals for calculating the duties of each phase of the multiphase DC-DC converter. Therefore, fewer bit devices can be used to achieve precise current balance control and the size and cost of the circuit can be reduced.
    Type: Application
    Filed: March 11, 2010
    Publication date: September 23, 2010
    Applicant: RICHTEK TECHNOLOGY CORP.
    Inventors: HUNG-SHOU NIEN, KUANG-YAO CHENG, YI-CHIANG FU, WEI-HSU CHANG
  • Publication number: 20100181952
    Abstract: An apparatus and method for use with a PMSM detect the fall time or the rise time and the fall time of a motor current in the PMSM under different voltage vectors when the PMSM is in start-up to determine an initial rotor position for the PMSM at standstill.
    Type: Application
    Filed: January 19, 2010
    Publication date: July 22, 2010
    Applicant: RICHTEK TECHNOLOGY CORP.
    Inventor: KUANG-YAO CHENG
  • Patent number: 7649329
    Abstract: A method and a circuit for controlling a motor and a brushless motor using the same are provided. The brushless motor includes three phase coils, wherein the first terminals of all the phase coils are coupled to a common node. The method includes following steps: among the above-mentioned three phase coils, when there is no current flowing through the first phase coil of the above-mentioned three phase coils and a current flows from the second terminal of the second coil to the second terminal of the third phase coil, detecting the voltage at the second terminal of the first phase coil to be a first specific voltage; detecting the voltage drop of a DC sensing resistor to be a second specific voltage; and utilizing the first specific voltage, the second specific voltage and the DC voltage supplied to the motor to estimate zero crossing points for controlling the motor.
    Type: Grant
    Filed: May 23, 2007
    Date of Patent: January 19, 2010
    Assignee: Prolific Technology Inc.
    Inventor: Kuang-Yao Cheng
  • Publication number: 20090212733
    Abstract: After an AC motor generates a three-phase current, modulate the three-phase current to generate an original voltage space vector, and add three detecting vectors with a sum of zero after the original voltage space vector. While adding the three detecting vectors, sample the current to generate a sampling result. Then adjust the width of pulses generated by a pulse width modulator according to the sampling result.
    Type: Application
    Filed: August 15, 2008
    Publication date: August 27, 2009
    Inventors: Tung-Chin Hsieh, Kuang-Yao Cheng
  • Publication number: 20080238349
    Abstract: A method and a circuit for controlling a motor and a brushless motor using the same are provided. The brushless motor includes three phase coils, wherein the first terminals of all the phase coils are coupled to a common node. The method includes following steps: among the above-mentioned three phase coils, when there is no current flowing through the first phase coil of the above-mentioned three phase coils and a current flows from the second terminal of the second coil to the second terminal of the third phase coil, detecting the voltage at the second terminal of the first phase coil to be a first specific voltage; detecting the voltage drop of a DC sensing resistor to be a second specific voltage; and utilizing the first specific voltage, the second specific voltage and the DC voltage supplied to the motor to estimate zero crossing points for controlling the motor.
    Type: Application
    Filed: May 23, 2007
    Publication date: October 2, 2008
    Applicant: PROLIFIC TECHNOLOGY INC.
    Inventor: Kuang-Yao Cheng
  • Patent number: 7075267
    Abstract: A motor driver has a plurality of output circuits each having an upper side switch and a lower side switch connected in series for supplying a current to a motor. The motor driver includes a current detection resistor connected in series with the plurality of output circuits in common for detecting a current supplied to the plurality of output circuits, a position detection circuit for outputting a position signal corresponding to a position of a rotor of the motor, a current command generation circuit for generating a target current command signal based on the position signal and a predetermined phase angle in which a phase angle of the target current command signal is determined by the predetermined phase angle, and a space vector modulation based logic control circuit for commanding a plurality of output circuits that are set in a plurality of switches states for control of an electric motor.
    Type: Grant
    Filed: December 29, 2004
    Date of Patent: July 11, 2006
    Assignee: Prolific Technology Inc.
    Inventor: Kuang-Yao Cheng
  • Publication number: 20060138994
    Abstract: A motor driver has a plurality of output circuits each having an upper side switch and a lower side switch connected in series for supplying a current to a motor. The motor driver includes a current detection resistor connected in series with the plurality of output circuits in common for detecting a current supplied to the plurality of output circuits, a position detection circuit for outputting a position signal corresponding to a position of a rotor of the motor, a current command generation circuit for generating a target current command signal based on the position signal and a predetermined phase angle in which a phase angle of the target current command signal is determined by the predetermined phase angle, and a space vector modulation based logic control circuit for commanding a plurality of output circuits that are set in a plurality of switches states for control of an electric motor.
    Type: Application
    Filed: December 29, 2004
    Publication date: June 29, 2006
    Inventor: Kuang-Yao Cheng