Patents by Inventor Yu-Fan Liao

Yu-Fan Liao 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: 7233134
    Abstract: A DC-to-DC converter comprises a sense circuit to sense the output voltage of the converter to generate a feedback signal, a transconductive amplifier to amplify a difference between the feedback signal and a threshold signal to generate a first current and to generate a second current in response to a load transient, a charging circuit connected with the first current to generate a charging voltage, a driver to compare the charging voltage with two reference signals to generate a pair of low-side and high-side driving signals, and a fast response circuit to compare a load transient signal corresponding to the second current with a third reference signal to generate a bypass signal to drive the output stage of the converter in the load transient.
    Type: Grant
    Filed: May 17, 2004
    Date of Patent: June 19, 2007
    Assignee: Richtek Technology Corp.
    Inventors: Kent Huang, Liang-Pin Tai, Hung-I Wang, Jian-Rong Huang, Kuo-Ping Liu, Yu-Fan Liao
  • Patent number: 6969980
    Abstract: A pulse width modulator includes an amplifier module, a comparator module, and a filter module. The amplifier module receives a feedback voltage signal from a passive network, and generates first and second non-inverted voltage signals and first and second inverted voltage signals in response to the feedback voltage signal. The comparator module receives the first and second non-inverted voltage signals and the first and second inverted voltage signals, and provides first and second differential voltage signals corresponding to the first and second non-inverted voltage signals and the first and second inverted voltage signals. The filter module is coupled between the amplifier module and the comparator module, and is operable so as to attenuate high frequency components of the first and second non-inverted voltage signals. As such, the presence of noise in the feedback voltage signal does not affect differential operation of the comparator module.
    Type: Grant
    Filed: May 21, 2004
    Date of Patent: November 29, 2005
    Assignee: Richtek Technology Corp.
    Inventors: Liang-Pin Tai, Kent Hwang, Jian-Rong Huang, Kuo-Ping Liu, Cheng-Hsuan Fan, Ko-Cheng Wang, Yu-Fan Liao
  • Publication number: 20050258813
    Abstract: A pulse width modulator includes an amplifier module, a comparator module, and a filter module. The amplifier module receives a feedback voltage signal from a passive network, and generates first and second non-inverted voltage signals and first and second inverted voltage signals in response to the feedback voltage signal. The comparator module receives the first and second non-inverted voltage signals and the first and second inverted voltage signals, and provides first and second differential voltage signals corresponding to the first and second non-inverted voltage signals and the first and second inverted voltage signals. The filter module is coupled between the amplifier module and the comparator module, and is operable so as to attenuate high frequency components of the first and second non-inverted voltage signals. As such, the presence of noise in the feedback voltage signal does not affect differential operation of the comparator module.
    Type: Application
    Filed: May 21, 2004
    Publication date: November 24, 2005
    Inventors: Liang-Pin Tai, Kent Hwang, Jian-Rong Huang, Kuo-Ping Liu, Cheng-Hsuan Fan, Ko-Cheng Wang, Yu-Fan Liao
  • Patent number: 6946823
    Abstract: A delta-sigma DC-to-DC converter comprises a pair of high-side and low-side switches switched to convert an input voltage to an output voltage, a sense circuit to sense the output voltage of the converter to generate a feedback signal, a transconductive amplifier to amplify a difference between the feedback signal and a threshold signal to generate a differential current, a charging circuit connected with the differential current to generate a charging voltage, and a driver to compare the charging voltage with two reference signals to generate the pair of low-side and high-side driving signals.
    Type: Grant
    Filed: May 17, 2004
    Date of Patent: September 20, 2005
    Assignee: Richtek Technology Corp.
    Inventors: Kent Huang, Liang-Pin Tai, Hung-I Wang, Jian-Rong Huang, Kuo-Ping Liu, Yu-Fan Liao
  • Publication number: 20040232901
    Abstract: A delta-sigma DC-to-DC converter comprises a pair of high-side and low-side switches switched to convert an input voltage to an output voltage, a sense circuit to sense the output voltage of the converter to generate a feedback signal, a transconductive amplifier to amplify a difference between the feedback signal and a threshold signal to generate a differential current, a charging circuit connected with the differential current to generate a charging voltage, and a driver to compare the charging voltage with two reference signals to generate the pair of low-side and high-side driving signals.
    Type: Application
    Filed: May 17, 2004
    Publication date: November 25, 2004
    Inventors: Kent Huang, Liang-Pin Tai, Hung-I Wang, Jian-Rong Huang, Kuo-Ping Liu, Yu-Fan Liao
  • Publication number: 20040232900
    Abstract: A DC-to-DC converter comprises a sense circuit to sense the output voltage of the converter to generate a feedback signal, a transconductive amplifier to amplify a difference between the feedback signal and a threshold signal to generate a first current and to generate a second current in response to a load transient, a charging circuit connected with the first current to generate a charging voltage, a driver to compare the charging voltage with two reference signals to generate a pair of low-side and high-side driving signals, and a fast response circuit to compare a load transient signal corresponding to the second current with a third reference signal to generate a bypass signal to drive the output stage of the converter in the load transient.
    Type: Application
    Filed: May 17, 2004
    Publication date: November 25, 2004
    Inventors: Kent Huang, Liang-Pin Tai, Hung-I Wang, Jian-Rong Huang, Kuo-Ping Liu, Yu-Fan Liao