Patents by Inventor Junqiang Shang

Junqiang Shang 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: 8548773
    Abstract: A voltage controlled delay line (VCDL) for measuring the maximum speed of a chip includes a first input configured to receive a reference clock signal, a first output configured to output an output clock signal, and a second input configured to receive a phase error signal representing a phase delay between the reference and output clock signals. A register stores a delay code applied by the VCDL to the reference clock signal to delay the reference clock signal to generate the output clock signal. The delay code is adjusted according to the phase error signal until the phase delay is equal to a predetermined value. A second output is coupled to an interface that reads the delay code from the register and outputs the delay code to automated testing equipment when the phase delay is equal to the predetermined value. The outputted delay code corresponds to the maximum chip speed.
    Type: Grant
    Filed: October 28, 2009
    Date of Patent: October 1, 2013
    Assignee: Integrated Device Technology, Inc.
    Inventors: Junqiang Shang, Liang Zhang, Yong Wang, Xin Liu
  • Patent number: 8254515
    Abstract: A method for measuring a phase locked loop bandwidth parameter for a high-speed serial link includes the steps of initiating a jitter frequency of a clock input of a phase locked loop equal to a reference frequency with a frequency generator; determining a reference jitter amplitude value of a clock output of the phase locked loop with a waveform analyzer at the reference frequency, the reference jitter amplitude value being a function of a time interval error jitter trend of the clock output at the reference frequency; and adjusting the jitter frequency of the clock input with the frequency generator until an adjusted jitter amplitude value of the clock output reaches a goal value as determined by the waveform analyzer, the adjusted jitter amplitude being a function of a time interval error trend of the clock output at the adjusted frequency.
    Type: Grant
    Filed: March 24, 2009
    Date of Patent: August 28, 2012
    Assignee: Integrated Device Technology, Inc.
    Inventors: Dongming Lou, Pengfei Hu, Junqiang Shang, Xin Liu
  • Publication number: 20110098977
    Abstract: A voltage controlled delay line (VCDL) for measuring the maximum speed of a chip includes a first input configured to receive a reference clock signal, a first output configured to output an output clock signal, and a second input configured to receive a phase error signal representing a phase delay between the reference and output clock signals. A register stores a delay code applied by the VCDL to the reference clock signal to delay the reference clock signal to generate the output clock signal. The delay code is adjusted according to the phase error signal until the phase delay is equal to a predetermined value. A second output is coupled to an interface that reads the delay code from the register and outputs the delay code to automated testing equipment when the phase delay is equal to the predetermined value. The outputted delay code corresponds to the maximum chip speed.
    Type: Application
    Filed: October 28, 2009
    Publication date: April 28, 2011
    Applicant: INTEGRATED DEVICE TECHNOLOGY, INC.
    Inventors: Junqiang SHANG, Liang ZHANG, Yong WANG, Xin LIU
  • Publication number: 20100246739
    Abstract: A method for measuring a phase locked loop bandwidth parameter for a high-speed serial link includes the steps of initiating a jitter frequency of a clock input of a phase locked loop equal to a reference frequency with a frequency generator, determining a reference jitter amplitude value of a clock output of the phase locked loop with a waveform analyzer at the reference frequency, the reference jitter amplitude value being a function of a time interval error jitter trend of the clock output at the reference frequency; and adjusting the jitter frequency of the clock input with the frequency generator until an adjusted jitter amplitude value of the clock output reaches a goal value as determined by the waveform analyzer, the adjusted jitter amplitude being a function of a time interval error trend of the clock output at the adjusted frequency.
    Type: Application
    Filed: March 24, 2009
    Publication date: September 30, 2010
    Inventors: Dongming Lou, Pengfei Hu, Junqiang Shang, Xin Liu