Patents by Inventor Chongming Qiao

Chongming Qiao 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: 20090079408
    Abstract: A voltage controller and method providing multiple modes of operation. Embodiments include pulse-width modulation (PWM), feed-forward (FF), pulse-frequency modulation (PFM) and skip operation (PWM-FF-PFM/SKIP). Controller embodiments have integrated MOSFET components, comparator hysteresis, oscillator feed-forward, fixed gain, and error amplifier (EA) limits thereby providing improved efficiency and noise immunity.
    Type: Application
    Filed: April 23, 2008
    Publication date: March 26, 2009
    Applicant: NEXEM, INC.
    Inventors: Chongming Qiao, Reza Amirani, Vincent Condito, Amir Asvadi
  • Patent number: 7489119
    Abstract: A controller for a DC to DC converter with reference voltage loop disturbance compensation. The controller may include an error amplifier configured to receive a first signal representative of an actual output voltage of the DC to DC converter and a reference signal representative of a desired output voltage of the DC to DC converter and to provide an error signal representative of a difference between the first signal and the reference signal. The controller may also include a PWM modulator with reference voltage compensation circuitry configured to receive the error signal and compensate for a change in the reference signal in order to control overshoot and undershoot of the actual output voltage from a desired voltage due to the change of the reference signal. An electronic device and method are also provided.
    Type: Grant
    Filed: August 17, 2005
    Date of Patent: February 10, 2009
    Assignee: Nexem, Inc.
    Inventors: Mark Smith, Jr., Chongming Qiao, Reza Amirani
  • Patent number: 7254000
    Abstract: An over voltage protection circuit for single phase and multiphase buck converters. According to one embodiment, upon the occurrence of an over voltage condition, the high side switch is turned Off and the low side switch is On. As the output voltage drops below a lower threshold, the low side switch is turned Off thereby reducing or eliminating negative spikes on the voltage output.
    Type: Grant
    Filed: June 20, 2005
    Date of Patent: August 7, 2007
    Assignee: Nexem, Inc.
    Inventors: Mark Smith, Chongming Qiao, Vincent Condido, Reza Amironi, Amir Asvadi
  • Publication number: 20070040536
    Abstract: A controller for a DC to DC converter with reference voltage loop disturbance compensation. The controller may include an error amplifier configured to receive a first signal representative of an actual output voltage of the DC to DC converter and a reference signal representative of a desired output voltage of the DC to DC converter and to provide an error signal representative of a difference between the first signal and the reference signal. The controller may also include a PWM modulator with reference voltage compensation circuitry configured to receive the error signal and compensate for a change in the reference signal in order to control overshoot and undershoot of the actual output voltage from a desired voltage due to the change of the reference signal. An electronic device and method are also provided.
    Type: Application
    Filed: August 17, 2005
    Publication date: February 22, 2007
    Inventors: Mark Smith, Chongming Qiao, Reza Amirani
  • Patent number: 6751104
    Abstract: A DC-to-DC converter is coupled to an AC source comprising a rectifier bridge. An input inductor is coupled to the output of the rectifier stage. An auxiliary winding is coupled to the input inductor. The auxiliary winding is characterized by a first number of turns. A storage capacitor is coupled to the auxiliary winding. An output transformer is coupled to the auxiliary winding. A first switch is coupled in series with the primary of the output transformer. The first switch and primary are coupled in parallel with the storage capacitor to the auxiliary winding. The number of turns of the auxiliary is less than the number of turns of the primary so that voltage across the storage capacitor is reduced without load carrying capacity of the DC-to-DC converter.
    Type: Grant
    Filed: November 14, 2002
    Date of Patent: June 15, 2004
    Assignee: The Regents of the University of California
    Inventors: Chongming Qiao, Keyue M. Smedley, Thomas A. Brooks, Tetsuhiko Shimpo
  • Publication number: 20030227784
    Abstract: A DC-to-DC converter is coupled to an AC source (12) including a rectifier bridge (20). An input inductor (24) is coupled to the output of the rectifier stage. An auxiliary winding is coupled to the input inductor (24). The auxiliary winding (26) is characterized by a first number of turns. A storage capacitor (34) is coupled to the auxiliary winding (26). An output transformer (38) is coupled to the auxiliary winding (26). A first switch (46) is coupled in series with the primary (36) of the output transformer (38). The first switch (46) and primary (36) are coupled in parallel with the storage capacitor (34) to the auxiliary winding (26). The number of turns of the auxiliary (26) is less than the number of turns of the primary (36) so that voltage across the storage capacitor (34) is reduced without load carrying capacity of the DC-to-DC converter.
    Type: Application
    Filed: November 14, 2002
    Publication date: December 11, 2003
    Inventors: Chongming Qiao, Keyue M Smedley, Thomas A Brooks, Tetsuhiko Shimpo
  • Patent number: 6545887
    Abstract: An unified constant-frequency integration (UCI) control method based on one-cycle control employs an integrator with reset as its core component along with a few logic and linear components to control the pulse width of a three-phase recitifier, active power filter, or grid-connected inverter so that the all three phase current draw from or the current output to the utility line is sinusoidal. No multipliers and reference calculation circuitry are needed for controlling active power filters. The UCI control employs constant switching frequency and operates in continuous conduction mode (CCM). If in some cases a DSP is desired for some other purposes, the Unified Constant-frequency Control function can be realized by a low cost DSP with a high reliability, because no high speed calcutation, high speed A/D converter, and mutipliers are required.
    Type: Grant
    Filed: August 10, 2001
    Date of Patent: April 8, 2003
    Assignee: The Regents of the University of California
    Inventors: Keyue M. Smedley, Chongming Qiao
  • Publication number: 20020149953
    Abstract: An unified constant-frequency integration (UCI) control method based on one-cycle control employs an integrator with reset as its core component along with a few logic and linear components to control the pulse width of a three-phase recitifier, active power filter, or grid-connected inverter so that the all three phase current draw from or the current output to the utility line is sinusoidal. No multipliers and reference calculation circuitry are needed for controlling active power filters. The UCI control employs constant switching frequency and operates in continuous conduction mode (CCM). If in some cases a DSP is desired for some other purposes, the Unified Constant-frequency Control function can be realized by a low cost DSP with a high reliability, because no high speed calcutation, high speed A/D converter, and mutipliers are required.
    Type: Application
    Filed: August 10, 2001
    Publication date: October 17, 2002
    Inventors: Keyue M. Smedley, Chongming Qiao
  • Patent number: 6297980
    Abstract: The unified constant-frequency integration (UCI) control method of the invention is based on one-cycle control. It employs an integrator with reset as its core component along with a few logic and linear components to control the pulse width of a three-phase rectifier, active power filter, or grid-connected inverter so that the three phase current draw from, or the current output to, the utility line is sinusoidal. The UCI control employs constant switching frequency and operates in continuous conduction mode (CCM) that is desirable for industrial applications.
    Type: Grant
    Filed: August 4, 2000
    Date of Patent: October 2, 2001
    Assignee: The Regents of the University of California
    Inventors: Keyue M. Smedley, Chongming Qiao