Patents by Inventor Kaiwei Yao

Kaiwei Yao 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: 7443330
    Abstract: The present invention introduces methods to eliminate 1-bit jitter problem in the N-bit A/D conversion applications. The methods do not require any increase in the total bit of A/D conversion.
    Type: Grant
    Filed: June 8, 2006
    Date of Patent: October 28, 2008
    Assignee: Monolithic Power Systems, Inc.
    Inventors: Kaiwei Yao, Zhou Lu
  • Publication number: 20080258651
    Abstract: A detector circuit monitors the phase relationship between the lamp voltage and the excitation voltage, and if one or more conditions are met, triggers the open lamp protection process in a discharge lamp system. The detection circuit can be incorporated into a lamp voltage feedback circuit and implemented on the integrated circuit level with less cost and circuit complexity.
    Type: Application
    Filed: June 24, 2008
    Publication date: October 23, 2008
    Applicant: Monolithic Power Systems, Inc.
    Inventors: Yuancheng Ren, Kaiwei Yao, Wei Chen
  • Patent number: 7423384
    Abstract: A circuit comprises a detector circuit and a protection triggering circuit in a discharge lamp system. The detector circuit detects both open lamp and shorted lamp conditions and is coupled with detecting devices, such as sensing capacitors. A DC bias is added to the sensing capacitors so that capacitor voltages are always greater than zero volts. The output voltage of the detector circuit is coupled to the protection triggering circuit, which triggers an open lamp protection when open lamp condition occurs and a shorted lamp protection when shorted lamp condition occurs.
    Type: Grant
    Filed: November 8, 2005
    Date of Patent: September 9, 2008
    Assignee: Monolithic Power Systems, Inc.
    Inventors: Yuancheng Ren, Kaiwei Yao, Wei Chen
  • Patent number: 7420337
    Abstract: A method for responding to an open lamp condition in a discharge lamp system is disclosed. The method monitors a current feedback signal flowing through a lamp and a voltage feedback signal indicative of a voltage across said lamp. A switch is used to switch between the current feedback signal to the voltage feedback signal upon detection of an open lamp condition.
    Type: Grant
    Filed: May 31, 2006
    Date of Patent: September 2, 2008
    Assignee: Monolithic Power Systems, Inc.
    Inventors: Yuancheng Ren, Peng Xu, Kaiwei Yao, Wei Chen
  • Patent number: 7420829
    Abstract: Control methods and apparatus are disclosed for operating an inverter at resonant mode, where the inverter adapts its frequency to the resonant tank characteristics before a lamp is struck, and operates at fixed frequency after the lamp is struck. Disclosed embodiments combine the advantages of operation in fixed mode as well as the variable mode.
    Type: Grant
    Filed: August 25, 2005
    Date of Patent: September 2, 2008
    Assignee: Monolithic Power Systems, Inc.
    Inventors: Kaiwei Yao, Wei Chen, David Meng
  • Patent number: 7394203
    Abstract: A detector circuit monitors the phase relationship between the lamp voltage and the excitation voltage, and if one or more conditions are met, triggers the open lamp protection process in a discharge lamp system. The detection circuit can be incorporated into a lamp voltage feedback circuit and implemented on the integrated circuit level with less cost and circuit complexity.
    Type: Grant
    Filed: December 15, 2005
    Date of Patent: July 1, 2008
    Assignee: Monolithic Power Systems, Inc.
    Inventors: Yuancheng Ren, Kaiwei Yao, Wei Chen
  • Publication number: 20080068230
    Abstract: The present invention introduces methods to eliminate 1-bit jitter problem in the N-bit A/D conversion applications. The methods do not require any increase in the total bit of A/D conversion.
    Type: Application
    Filed: June 8, 2006
    Publication date: March 20, 2008
    Inventors: Kaiwei Yao, Zhou Lu
  • Publication number: 20070278971
    Abstract: A method for responding to an open lamp condition in a discharge lamp system is disclosed. The method monitors a current feedback signal flowing through a lamp and a voltage feedback signal indicative of a voltage across said lamp. A switch is used to switch between the current feedback signal to the voltage feedback signal upon detection of an open lamp condition.
    Type: Application
    Filed: May 31, 2006
    Publication date: December 6, 2007
    Applicant: Monolithic Power Systems, Inc.
    Inventors: Yuancheng Ren, Peng Xu, Kaiwei Yao, Wei Chen
  • Publication number: 20070247085
    Abstract: The method and circuit of the present invention provides short-circuit detection and protection in a discharge lamp system. The transformer's primary current is sensed and used to provide short-circuit protection of the secondary winding side or high voltage side. The system and method with the present invention provides short-circuit detection and protection even when the transformer's secondary winding is shorted.
    Type: Application
    Filed: April 19, 2006
    Publication date: October 25, 2007
    Applicant: Monolithic Power Systems, Inc.
    Inventors: Kaiwei Yao, James Moyer, Wei Chen
  • Publication number: 20070242022
    Abstract: The present invention introduces methods to modify the burst frequency of an inverter in a given LCD panel without any component change on the inverter board. The present invention also introduces methods to adjust the setting of a sensing system for duty cycles and accept Display Power Saving Technology (DPST) input signals with different frequencies. The universal inverter module with the present invention can be applied for different DPST technologies.
    Type: Application
    Filed: April 13, 2007
    Publication date: October 18, 2007
    Applicant: Monolithic Power Systems, Inc.
    Inventor: Kaiwei Yao
  • Publication number: 20070138977
    Abstract: A detector circuit monitors the phase relationship between the lamp voltage and the excitation voltage, and if one or more conditions are met, triggers the open lamp protection process in a discharge lamp system. The detection circuit can be incorporated into a lamp voltage feedback circuit and implemented on the integrated circuit level with less cost and circuit complexity.
    Type: Application
    Filed: December 15, 2005
    Publication date: June 21, 2007
    Applicant: Monolithic Power Systems, Inc.
    Inventors: Yuancheng Ren, Kaiwei Yao, Wei Chen
  • Publication number: 20070103096
    Abstract: A circuit comprises a detector circuit and a protection triggering circuit in a discharge lamp system. The detector circuit detects both open lamp and shorted lamp conditions and is coupled with detecting devices, such as sensing capacitors. A DC bias is added to the sensing capacitors so that capacitor voltages are always greater than zero volts. The output voltage of the detector circuit is coupled to the protection triggering circuit, which triggers an open lamp protection when open lamp condition occurs and a shorted lamp protection when shorted lamp condition occurs.
    Type: Application
    Filed: November 8, 2005
    Publication date: May 10, 2007
    Applicant: Monolithic Power Systems, Inc.
    Inventors: Yuancheng Ren, Kaiwei Yao, Wei Chen
  • Publication number: 20070046353
    Abstract: Control methods and apparatus are disclosed for operating an inverter at resonant mode, where the inverter adapts its frequency to the resonant tank characteristics before a lamp is struck, and operates at fixed frequency after the lamp is struck. Disclosed embodiments combine the advantages of operation in fixed mode as well as the variable mode.
    Type: Application
    Filed: August 25, 2005
    Publication date: March 1, 2007
    Inventors: Kaiwei Yao, Wei Chen, David Meng
  • Patent number: 6784644
    Abstract: Voltage regulation, transient response and efficiency of a voltage regulator module (VRM) is improved where short duty cycles are necessitated by large differentials of input and output voltage by including at least one clamping of a tap of an inductance in series with an output of each of a plurality of parallel branches or phases which are switched in a complementary fashion or providing coupling between inductors of respective phases. Such coupling between inductors is achieved in a small module with an integrated magnetic structure. Reduced component counts are achieved while deriving built-in input and output filters. Principals of the invention can be extended to isolation applications and push-pull forward converts, in particular. A lossless clamping circuit is also provided allowing spike currents to be suppressed while returning power to the output of the VRM.
    Type: Grant
    Filed: February 22, 2002
    Date of Patent: August 31, 2004
    Assignee: Virginia Tech Intellectual Properties, Inc.
    Inventors: Peng Xu, Kaiwei Yao, Fred C. Lee, Mao Ye, Jia Wei
  • Publication number: 20020118000
    Abstract: Voltage regulation, transient response and efficiency of a voltage regulator module (VRM) is improved where short duty cycles are necessitated by large differentials of input and output voltage by including at least one clamping of a tap of an inductance in series with an output of each of a plurality of parallel branches or phases which are switched in a complementary fashion or providing coupling between inductors of respective phases. Such coupling between inductors is achieved in a small module with an integrated magnetic structure. Reduced component counts are achieved while deriving built-in input and output filters. Principals of the invention can be extended to isolation applications and push-pull forward converts, in particular. A lossless clamping circuit is also provided allowing spike currents to be suppressed while returning power to the output of the VRM.
    Type: Application
    Filed: February 22, 2002
    Publication date: August 29, 2002
    Inventors: Peng Xu, Kaiwei Yao, Fred C. Lee, Mao Ye, Jia Wei