Patents by Inventor Cheng Wan

Cheng Wan 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: 9805047
    Abstract: A disclosed computer-implemented method for retrieving data may include (1) receiving a request to retrieve data segments from a storage system that stores data segments in a plurality of data containers, (2) obtaining, for each data segment, information that indicates which data container stores the data segment, (3) determining, based on the information that indicates which data container stores each data segment, that using an initial access order to retrieve the data segments would result in visiting one or more data containers more than one time, (4) rearranging access to one or more data segments such that retrieving the data segments results in visiting the data containers at least one fewer times than using the initial access order, and (5) retrieving the data segments from the storage system based on the rearranged access order. Various other methods, systems, and computer-readable media are also disclosed.
    Type: Grant
    Filed: May 21, 2014
    Date of Patent: October 31, 2017
    Assignee: Veritas Technologies LLC
    Inventors: Lei Hu Zhang, Cheng Wan
  • Publication number: 20170279352
    Abstract: A duty cycle estimation circuit includes a latch circuit that receives a clock signal for a voltage regulator. The latch circuit outputs a duty cycle estimate. The duty cycle estimation circuit also includes a low pass filter coupled to an output of the latch circuit to receive the duty cycle estimate. The duty cycle estimation circuit further includes a comparator that receives, as input, an output of the low pass filter and a voltage regulator output. The comparator feeds back a feedback signal to the latch circuit.
    Type: Application
    Filed: November 10, 2016
    Publication date: September 28, 2017
    Inventors: Ajay Kumar KOSARAJU, Guolei YU, Yi-Cheng WAN, Sugato MUKHERJEE
  • Patent number: 8917072
    Abstract: A control circuit and method for a PWM voltage regulator combine a high frequency feedback technique with a constant on-time or constant off-time topology to improve the transient performance of the PWM voltage regulator. The PWM voltage regulator generates a constant on-time or constant off-time depending on a current for generating a PWM signal, and dynamically adjusts the current according to the droop-voltage at its output during a transient period. Therefore, the PWM voltage regulator boosts its transient response without any threshold for load step detection.
    Type: Grant
    Filed: June 1, 2012
    Date of Patent: December 23, 2014
    Assignee: Richtek Technology Corp.
    Inventors: Yi-Cheng Wan, Jian-Rong Huang, Wen-Wei Chen
  • Patent number: 8917077
    Abstract: The present invention provides a multi-phase switching regulator and a droop circuit for use in the multi-phase switching regulator. The multi-phase switching regulator generates pulse width modulation (PWM) signals according to an output voltage and a droop signal, to drive a plurality of switching sets to convert an input voltage to the output voltage. The droop circuit detects the sum of the currents generated by the plurality of switching sets and provides the droop signal which is related to the sum of the currents to the multi-phase switching regulator. The droop signal can be used for over current protection (OCP) or for the droop control.
    Type: Grant
    Filed: July 9, 2013
    Date of Patent: December 23, 2014
    Assignee: Richtek Technology Corporation
    Inventors: Yu-Ta Lin, Jian-Rong Huang, Yi-Cheng Wan, Chien-Hui Wang, Yuan-Wen Hsiao
  • Patent number: 8836307
    Abstract: In a PWM signal generation method of a voltage regulator, an output sense signal, a first ramp signal and a second ramp signal are provided. A first time point of the first ramp signal crossing with the output sense signal is used to determine a start point of an ON-time of a PWM signal, and a second time point of the second ramp signal crossing with the output sense signal is used to determine an end point of the ON-time of the PWM signal. Moreover, the first ramp signal is reset to a reference voltage at the first time point and then maintained at the reference voltage, and further ramps down starting from the end point of the ON-time. The second ramp signal ramps up starting from the start point of the ON-time, and then is reset to a preset voltage at the second time point.
    Type: Grant
    Filed: March 2, 2011
    Date of Patent: September 16, 2014
    Assignee: Richtek Technology Corp.
    Inventors: Yi-Cheng Wan, Jian-Rong Huang, Chien-Hui Wang, Cheng-Feng Chung
  • Patent number: 8766617
    Abstract: An exemplary method for improving voltage identification (VID) transient response is adapted to a voltage regulator and includes steps of: continuously sensing an inductor current of the voltage regulator to thereby output a current sense signal; during a steady state operation period, sampling the current sense signal to thereby obtain a sampling result for providing a droop control signal; after entering a VID transient period from the steady state operation period, holding the sampling result for providing the droop control signal; and taking the droop control signal as a consideration factor of producing a pulse width modulation signal to regulate an output voltage of the voltage regulator.
    Type: Grant
    Filed: February 11, 2011
    Date of Patent: July 1, 2014
    Assignee: Richtek Technology Corp
    Inventors: Yi-Cheng Wan, Jian-Rong Huang, Cheng-Feng Chung, Hung-Chun Peng
  • Publication number: 20140021929
    Abstract: The present invention provides a multi-phase switching regulator and a droop circuit for use in the multi-phase switching regulator. The multi-phase switching regulator generates pulse width modulation (PWM) signals according to an output voltage and a droop signal, to drive a plurality of switching sets to convert an input voltage to the output voltage. The droop circuit detects the sum of the currents generated by the plurality of switching sets and provides the droop signal which is related to the sum of the currents to the multi-phase switching regulator. The droop signal can be used for over current protection (OCP) or for the droop control.
    Type: Application
    Filed: July 9, 2013
    Publication date: January 23, 2014
    Applicant: RICHTEK TECHNOLOGY CORPORATION
    Inventors: Yu-Ta Lin, Jian-Rong Huang, Yi-Cheng Wan, Chien-Hui Wang, Yuan-Wen Hsiao
  • Patent number: 8508206
    Abstract: The present invention discloses an adaptive constant ON time adjustment circuit, which generates a square wave signal having a constant normal ON time during normal operation, for controlling a power stage circuit to convert an input voltage to an output voltage. When the output voltage is shifted from low to high, during the transient period, the ON time is adjusted longer; and when the output voltage is shifted from high to low, during the transient period, the ON time is adjusted shorter.
    Type: Grant
    Filed: December 3, 2010
    Date of Patent: August 13, 2013
    Assignee: Richteck Technology Corporation
    Inventors: Yi-Cheng Wan, Hung-Chun Peng, Jian-Rong Huang, Kuo-Lung Tseng
  • Patent number: 8502515
    Abstract: A multiphase DC-DC converting circuit for providing power to a load is disclosed, having power stage circuits, channel current converting circuits, current detecting circuits, a transconductance amplifier circuit, a comparator circuit, and a channel current balance circuit. The current detecting circuits detect current signals of current channels, and the transconductance amplifier circuit and the comparator circuit are coupled with the current detecting circuits to receive the voltage difference across a resistor, and to generate a total current detecting signal provided to the load. The channel current converting circuit is coupled with the current detecting circuits to generate channel current detecting signals. The channel current balance circuit is coupled with the comparator circuit, the transconductance amplifier circuit and the channel current converting circuit to balance the current signals of the current channels.
    Type: Grant
    Filed: February 26, 2013
    Date of Patent: August 6, 2013
    Assignee: Richtek Technology Corporation
    Inventors: Yi-Cheng Wan, Jian-Rong Huang, Hung-Chun Peng
  • Publication number: 20130057237
    Abstract: The present invention discloses a multi-phase switching regulator and a droop circuit therefor. The droop circuit includes: multiple first resistors, which are coupled to corresponding phase nodes respectively to sense current through the phase nodes; a second resistor, which is coupled to the multiple first resistors; an error amplifier circuit, which has an inverting input end and a non-inverting input end, wherein the inverting input end is coupled to the second resistor and an output end of the error amplifier circuit, and the non-inverting input end is coupled to an output node; and a droop capacitor, which is coupled between the second resistor and the output node; wherein the droop circuit provides the droop signal according to a voltage drop across the second resistor or current through the second resistor.
    Type: Application
    Filed: September 6, 2011
    Publication date: March 7, 2013
    Inventors: An-Tung Chen, Yuan-Wen Hsiao, Yi-Cheng Wan
  • Publication number: 20120306586
    Abstract: A control circuit and method for a PWM voltage regulator combine a high frequency feedback technique with a constant on-time or constant off-time topology to improve the transient performance of the PWM voltage regulator. The PWM voltage regulator generates a constant on-time or constant off-time depending on a current for generating a PWM signal, and dynamically adjusts the current according to the droop-voltage at its output during a transient period. Therefore, the PWM voltage regulator boosts its transient response without any threshold for load step detection.
    Type: Application
    Filed: June 1, 2012
    Publication date: December 6, 2012
    Inventors: Yi-Cheng WAN, Jian-Rong Huang, Wen-Wei Chen
  • Publication number: 20120183805
    Abstract: A coated article includes a substrate and a color layer formed on the substrate. The substrate is made of aluminum or aluminum alloy. The color layer includes an aluminum layer formed on the substrate and an aluminum oxide layer formed on the aluminum layer. In the CIE LAB color system, L* coordinate of the color layer is between 75 and 100, a* coordinate of the color layer is between ?1 and 1, b* coordinate of the color layer is between ?1 and 1. The coated article has a white color.
    Type: Application
    Filed: September 15, 2011
    Publication date: July 19, 2012
    Applicants: HON HAI PRECISION INDUSTRY CO., LTD., HONG FU JIN PRECISION INDUSTRY (ShenZhen) CO., LTD .
    Inventors: HSIN-PEI CHANG, WEN-RONG CHEN, HUANN-WU CHIANG, CHENG-SHI CHEN, ZI-CHENG WAN
  • Publication number: 20120153913
    Abstract: An exemplary method for improving voltage identification (VID) transient response is adapted to a voltage regulator and includes steps of: continuously sensing an inductor current of the voltage regulator to thereby output a current sense signal; during a steady state operation period, sampling the current sense signal to thereby obtain a sampling result for providing a droop control signal; after entering a VID transient period from the steady state operation period, holding the sampling result for providing the droop control signal; and taking the droop control signal as a consideration factor of producing a pulse width modulation signal to regulate an output voltage of the voltage regulator.
    Type: Application
    Filed: February 11, 2011
    Publication date: June 21, 2012
    Applicant: RICHTEK TECHNOLOGY CORP
    Inventors: Yi-Cheng Wan, Jian-Rong Huang, Cheng-Feng Chung, Hung-Chun Peng
  • Publication number: 20120146608
    Abstract: In a PWM signal generation method of a voltage regulator, an output sense signal, a first ramp signal and a second ramp signal are provided. A first time point of the first ramp signal crossing with the output sense signal is used to determine a start point of an ON-time of a PWM signal, and a second time point of the second ramp signal crossing with the output sense signal is used to determine an end point of the ON-time of the PWM signal. Moreover, the first ramp signal is reset to a reference voltage at the first time point and then maintained at the reference voltage, and further ramps down starting from the end point of the ON-time. The second ramp signal ramps up starting from the start point of the ON-time, and then is reset to a preset voltage at the second time point.
    Type: Application
    Filed: March 2, 2011
    Publication date: June 14, 2012
    Applicant: RICHTEK TECHNOLOGY CORP
    Inventors: Yi-Cheng WAN, Jian-Rong HUANG, Chien-Hui WANG, Cheng-Feng CHUNG
  • Publication number: 20110304308
    Abstract: The present invention discloses an adaptive constant ON time adjustment circuit, which generates a square wave signal having a constant normal ON time during normal operation, for controlling a power stage circuit to convert an input voltage to an output voltage. When the output voltage is shifted from low to high, during the transient period, the ON time is adjusted longer; and when the output voltage is shifted from high to low, during the transient period, the ON time is adjusted shorter.
    Type: Application
    Filed: December 3, 2010
    Publication date: December 15, 2011
    Inventors: Yi-Cheng Wan, Hung-Chun Peng, Jian-Rong Huang, Kuo-Lung Tseng
  • Patent number: 7839668
    Abstract: A multiple output AC/DC power adapter is provided. The adapter includes an adapter body with an output connector and more than one output plugs configured for connecting with the output connector. The adapter body includes a DC-DC converting circuit having an input terminal, an output terminal, a first adjustment terminal. The output connector includes a positive terminal, a second adjustment terminal and a negative terminal configured for connecting to the output terminal and the first adjustment terminal of the DC-DC converting circuit and ground correspondingly. The output plugs each includes an adjustment resistor having a resistance value different from the other output plugs. Therefore, when equipped with a plurality of output plugs each of the plurality of plugs having different resistor R0, the adapter can supply different output DC voltages for different electronic device.
    Type: Grant
    Filed: June 5, 2008
    Date of Patent: November 23, 2010
    Assignees: Hong Fu Jin Precision Industry (ShenZhen) Co., Ltd., Hon Hai Precision Industry Co., Ltd.
    Inventors: Shih-Fang Wong, Tsung-Jen Chuang, Xiang-Cheng Wan
  • Publication number: 20090009153
    Abstract: A multiple output AC/DC power adapter is provided. The adapter includes an adapter body with an output connector and more than one output plugs configured for connecting with the output connector. The adapter body includes a DC-DC converting circuit having an input terminal, an output terminal, a first adjustment terminal. The output connector includes a positive terminal, a second adjustment terminal and a negative terminal configured for connecting to the output terminal and the first adjustment terminal of the DC-DC converting circuit and ground correspondingly. The output plugs each includes an adjustment resistor having a resistance value different from the other output plugs. Therefore, when equipped with a plurality of output plugs each of the plurality of plugs having different resistor R0, the adapter can supply different output DC voltages for different electronic device.
    Type: Application
    Filed: June 5, 2008
    Publication date: January 8, 2009
    Applicants: HONG FU JIN PRECISION INDUSTRY (ShenZhen) CO., LTD, HON HAI PRECISION INDUSTRY CO., LTD.
    Inventors: Shih-Fang Wong, Tsung-Jen Chuang, Xiang-Cheng Wan
  • Publication number: 20080309757
    Abstract: An audio-video playing system capable of detecting a remote control distance includes a remote control device and an audio-video playing device. The remote control device has a transmitting unit, a first control unit, and an input interface. When the input interface is enabled, the first control unit controls the transmitting unit to transmit a signal. The audio-video playing device has a receiving unit and a second control unit electrically connected to the receiving unit. The receiving unit receives the signal. The second control unit calculates a distance value of a distance between the remote control device and the audio-video playing device according to the signal. In addition, an audio-video playing method capable of detecting a remote control distance is also provided.
    Type: Application
    Filed: May 29, 2008
    Publication date: December 18, 2008
    Inventors: Chih-Cheng WAN, Jing-Rung Wang