Patents by Inventor Xinqing Chen

Xinqing Chen 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: 10367494
    Abstract: An apparatus includes a first circuit and a second circuit. The first circuit may be configured to generate a waveform in response to a frequency of an input clock signal and a threshold frequency. The second circuit may be configured to generate a control signal in response to a type of the waveform. The type of the waveform may comprise at least one of pulses and a steady state. The control signal may have a first state when the type of the waveform is the pulses and a second state when the type of the waveform is the steady state. A width of the pulses may be based on the threshold frequency.
    Type: Grant
    Filed: October 9, 2018
    Date of Patent: July 30, 2019
    Assignee: INTEGRATED DEVICE TECHNOLOGY, INC.
    Inventors: Xinqing Chen, HaiQi Liu, Yuan Zhang
  • Patent number: 10211843
    Abstract: An apparatus comprising an analog circuit and a digital circuit. The analog circuit may be configured to (i) receive pulses generated in response to a comparison of a feedback signal and a reference signal, (ii) filter the pulses when a frequency of the feedback signal is close to a frequency of the reference signal and (iii) generate an enable signal in response to the filtered pulses. The digital circuit may be configured to generate an output signal representing a lock status between (i) the feedback signal and (ii) the reference signal. The lock status may be determined (a) during a decision window based on a number of pulses of the reference signal and (b) when the enable signal is active (B) the decision window may be repeated periodically until the enable signal is not active.
    Type: Grant
    Filed: October 31, 2017
    Date of Patent: February 19, 2019
    Assignee: INTEGRATED DEVICE TECHNOLOGY, INC.
    Inventors: Xinqing Chen, HaiQi Liu, Yuan Zhang
  • Publication number: 20190044504
    Abstract: An apparatus includes a first circuit and a second circuit. The first circuit may be configured to generate a waveform in response to a frequency of an input clock signal and a threshold frequency. The second circuit may be configured to generate a control signal in response to a type of the waveform. The type of the waveform may comprise at least one of pulses and a steady state. The control signal may have a first state when the type of the waveform is the pulses and a second state when the type of the waveform is the steady state. A width of the pulses may be based on the threshold frequency.
    Type: Application
    Filed: October 9, 2018
    Publication date: February 7, 2019
    Inventors: Xinqing Chen, HaiQi Liu, Yuan Zhang
  • Patent number: 10135431
    Abstract: An apparatus comprising a first circuit and a second circuit. The first circuit may be configured to generate an intermediate signal in response to an input clock signal operating at a frequency. The first circuit may modify the input clock signal according to a threshold frequency to generate a waveform for the intermediate signal. The waveform of the intermediate signal may have at least one of (i) pulses and (ii) a steady state. The second circuit may be configured to generate a control signal in response to the intermediate signal. The second circuit may modify the intermediate signal to generate the control signal. The control signal may have a first state when the intermediate signal has pulses. The control signal may have a second state when the intermediate signal has the steady state.
    Type: Grant
    Filed: March 24, 2017
    Date of Patent: November 20, 2018
    Assignee: INTEGRATED DEVICE TECHNOLOGY, INC.
    Inventors: Xinqing Chen, HaiQi Liu, Yuan Zhang
  • Publication number: 20180212598
    Abstract: An apparatus comprising a first circuit and a second circuit. The first circuit may be configured to generate an intermediate signal in response to an input clock signal operating at a frequency. The first circuit may modify the input clock signal according to a threshold frequency to generate a waveform for the intermediate signal. The waveform of the intermediate signal may have at least one of (i) pulses and (ii) a steady state. The second circuit may be configured to generate a control signal in response to the intermediate signal. The second circuit may modify the intermediate signal to generate the control signal. The control signal may have a first state when the intermediate signal has pulses. The control signal may have a second state when the intermediate signal has the steady state.
    Type: Application
    Filed: March 24, 2017
    Publication date: July 26, 2018
    Inventors: Xinqing Chen, HaiQi Liu, Yuan Zhang
  • Publication number: 20180054208
    Abstract: An apparatus comprising an analog circuit and a digital circuit. The analog circuit may be configured to (i) receive pulses generated in response to a comparison of a feedback signal and a reference signal, (ii) filter the pulses when a frequency of the feedback signal is close to a frequency of the reference signal and (iii) generate an enable signal in response to the filtered pulses. The digital circuit may be configured to generate an output signal representing a lock status between (i) the feedback signal and (ii) the reference signal. The lock status may be determined (a) during a decision window based on a number of pulses of the reference signal and (b) when the enable signal is active (B) the decision window may be repeated periodically until the enable signal is not active.
    Type: Application
    Filed: October 31, 2017
    Publication date: February 22, 2018
    Inventors: Xinqing Chen, HaiQi Liu, Yuan Zhang
  • Patent number: 9831882
    Abstract: The invention concerns an apparatus comprising an analog circuit and a digital circuit. The analog circuit may be configured to generate an enable signal in response to (i) a comparison of a width of an up pulse and a pre-determined width and (ii) a comparison of a width of a down pulse and the pre-determined width. The up pulse and the down pulse may be generated in response to a comparison of a feedback signal and a reference signal. The enable signal may be active when both the comparisons are within a pre-determined threshold. The digital circuit may be configured to generate an output signal representing a lock status between (i) the feedback signal and (ii) the reference signal. The lock status may be determined (a) during a decision window based on a number of pulses of the reference signal and (b) when the enable signal is active.
    Type: Grant
    Filed: August 2, 2016
    Date of Patent: November 28, 2017
    Assignee: INTEGRATED DEVICE TECHNOLOGY, INC.
    Inventors: Xinqing Chen, HaiQi Liu, Yuan Zhang
  • Patent number: 9166835
    Abstract: Methods and systems for peak detection as part of automatic gain control in high-speed communications are provided. A peak detection system uses a portion of an input signal to generate a reference signal for comparison with the input signal. The comparison produces a differential error signal that is in turn used to produce one or more full swing pulses based on the comparison. A pulse counter counts the pulses, and if the count in a single clock cycle is above a determined threshold, a binary error signal is set to indicate a need for correction.
    Type: Grant
    Filed: March 9, 2012
    Date of Patent: October 20, 2015
    Assignee: INTEGRATED DEVICE TECHNOLOGY, INC
    Inventors: ChangXi Xu, XinQing Chen, YanBo Wang
  • Publication number: 20130235955
    Abstract: Methods and systems for peak detection as part of automatic gain control in high-speed communications are provided. A peak detection system uses a portion of an input signal to generate a reference signal for comparison with the input signal. The comparison produces a differential error signal that is in turn used to produce one or more full swing pulses based on the comparison. A pulse counter counts the pulses, and if the count in a single clock cycle is above a determined threshold, a binary error signal is set to indicate a need for correction.
    Type: Application
    Filed: March 9, 2012
    Publication date: September 12, 2013
    Applicant: INTERGRATED DEVICE TECHNOLOGY, INC.
    Inventors: ChangXi XU, XinQing CHEN, YanBo WANG
  • Publication number: 20110155669
    Abstract: The invention discloses a novel method for trace phosphate removal from water by using a composite resin. Firstly, adjusting the pH value of the raw water to 5.0˜9.0 and prefiltering the water, then leading the filtrate through an absorption tower packed with the composite resin, the trace phosphate in the water is therefore absorbed onto the composite resin; stopping the absorption run when it reaches the leakage point, using a binary NaOH-NaCl solution as the regenerant of the exhausted sorbent, followed by rinsing the composite resin-filled absorption tower with saturated carbon dioxide solution to regenerate the resin. In this invention, a composite resin with nanosized hydrated ferric oxide (HFO) or hydrous manganese dioxide (HMO) particles loaded on its surface is adopted as the absorbent for enhanced phosphate removal from water. A significant decrease of phosphate content in the effluent from this treatment system is found from 0.
    Type: Application
    Filed: August 10, 2009
    Publication date: June 30, 2011
    Applicant: NANJING UNIVERSITY
    Inventors: Bingcai Pan, Bingjun Pan, Qingjian Zhang, Hui Qiu, Weiming Zhang, Qing Su, Xinqing Chen, Quanxing Zhang