Patents by Inventor Khai Nguyen

Khai Nguyen 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: 9048823
    Abstract: Integrated circuits with clock generation and distribution circuitry are provided. Integrated circuits may include phase-locked loops configured to generate multiple clock signals that are delayed versions of one another. The clocks signal may be distributed to various regions on an integrated circuit using serially connected clock buffer blocks. Each buffer block may include bidirectional pairs of buffer circuits coupled in parallel. Each buffer circuit may have a first input configured to receive an input clock signal, an output at which a corrected version of the input clock signal is provided (e.g., an output at which an output clock signal with desired duty cycle is provided), a second input that receives a first delayed clock signal for setting the desired duty cycle for the output clock signal, and a third input that receives a second delayed clock signal that is high at least when the first delayed clock signal rises high.
    Type: Grant
    Filed: June 28, 2013
    Date of Patent: June 2, 2015
    Assignee: Altera Corporation
    Inventors: John Henry Bui, Lay Hock Khoo, Khai Nguyen, Chiakang Sung, Ket Chiew Sia
  • Patent number: 9001595
    Abstract: An integrated circuit may include memory interface circuitry that is used to communicate with off-chip memory. The memory interface circuitry may include data strobe (DQS) enable circuitry that receives DQS signals from the off-chip memory and that outputs a gated version of the DQS signals. The DQS enable circuitry may include an input buffer, a comparator, a latch, a flip-flop, a counter, and a gating circuit. The input buffer may receive an incoming DQS signal. The comparator may be used to determine when the incoming DQS signal starts to toggle. The latch may be used to control when a gating signal is asserted. The flip-flop controls the counter, which limits the duration that the gating signal is asserted. The gating circuit receives the DQS signal from the buffer and the gating signal and passes the DQS signal through to its output only when the gating signal is asserted.
    Type: Grant
    Filed: January 6, 2014
    Date of Patent: April 7, 2015
    Assignee: Altera Corporation
    Inventors: Wilma Shiao, Warren Nordyke, Khai Nguyen, Chiakang Sung
  • Patent number: 8968617
    Abstract: A resin flow-controlling apparatus for infusing composite reinforcement material with resin. The resin flow-controlling apparatus may have at least one viscosity valve to speed, slow, allow, or deny resin flow through the viscosity valve to the composite reinforcement material depending on the temperature of the viscosity valve. The viscosity valve may fluidly couple a resin reservoir with an enclosed chamber in which the composite reinforcement material resides. The viscosity valve may be thermally coupled with heating and/or cooling elements selectively variable between at least two different temperatures to affect viscosity of the resin and control resin flow from the resin reservoir into the composite reinforcement material. A vacuum port at an opposite end of the composite reinforcement material from the viscosity valve may fluidly couple with the enclosed chamber and a vacuum source may pull atmosphere and/or resin from the enclosed chamber and/or the resin reservoir.
    Type: Grant
    Filed: November 12, 2012
    Date of Patent: March 3, 2015
    Assignee: Spirit AeroSystems, Inc.
    Inventors: Mark A. Wadsworth, Adrienne M. Strohmeyer, Khai Nguyen
  • Publication number: 20140302878
    Abstract: Disclosed are various embodiments employed to generate location and proximity based reminders. To this end, a device is configured to generate its geographical location using a positioning system. The device detects when it impinges upon at least one geographical trigger based upon its geographical location. A predefined reminder is generated in the device when the device impinges upon the geographical trigger.
    Type: Application
    Filed: June 23, 2014
    Publication date: October 9, 2014
    Inventors: Christopher L. Scofield, Luan Khai Nguyen
  • Patent number: 8816743
    Abstract: An integrated circuit includes a clock circuit that may be used to provide clock signals to multiple input-output circuits. The integrated circuit may also include different clock structures. As an example, one of the clock structures may have multiple clock paths of substantially equal lengths while another clock structure may have a fly-by clock path. The multiple clock paths may be used to convey a subset of the clock signals to the input-output circuits. Similarly, the fly-by clock path may be used to transmit a second subset of the clock signals to the input-output circuits.
    Type: Grant
    Filed: January 24, 2013
    Date of Patent: August 26, 2014
    Assignee: Altera Corporation
    Inventors: Sean Shau-Tu Lu, Yan Chong, Kin Hong Au, Khai Nguyen
  • Publication number: 20140131916
    Abstract: A resin flow-controlling apparatus for infusing composite reinforcement material with resin. The resin flow-controlling apparatus may have at least one viscosity valve to speed, slow, allow, or deny resin flow through the viscosity valve to the composite reinforcement material depending on the temperature of the viscosity valve. The viscosity valve may fluidly couple a resin reservoir with an enclosed chamber in which the composite reinforcement material resides. The viscosity valve may be thermally coupled with heating and/or cooling elements selectively variable between at least two different temperatures to affect viscosity of the resin and control resin flow from the resin reservoir into the composite reinforcement material. A vacuum port at an opposite end of the composite reinforcement material from the viscosity valve may fluidly couple with the enclosed chamber and a vacuum source may pull atmosphere and/or resin from the enclosed chamber and/or the resin reservoir.
    Type: Application
    Filed: November 12, 2012
    Publication date: May 15, 2014
    Applicant: SPIRIT AEROSYSTEMS, INC.
    Inventors: Mark A. Wadsworth, Adrienne M. Strohmeyer, Khai Nguyen
  • Patent number: 8630131
    Abstract: An integrated circuit may include memory interface circuitry that is used to communicate with off-chip memory. The memory interface circuitry may include data strobe (DQS) enable circuitry that receives DQS signals from the off-chip memory and that outputs a gated version of the DQS signals. The DQS enable circuitry may include an input buffer, a comparator, a latch, a flip-flop, a counter, and a gating circuit. The input buffer may receive an incoming DQS signal. The comparator may be used to determine when the incoming DQS signal starts to toggle. The latch may be used to control when a gating signal is asserted. The flip-flop controls the counter, which limits the duration that the gating signal is asserted. The gating circuit receives the DQS signal from the buffer and the gating signal and passes the DQS signal through to its output only when the gating signal is asserted.
    Type: Grant
    Filed: July 30, 2012
    Date of Patent: January 14, 2014
    Assignee: Altera Corporation
    Inventors: Wilma Shiao, Warren Nordyke, Khai Nguyen, Chiakang Sung
  • Patent number: 8610462
    Abstract: Circuits and techniques for operating an integrated circuit (IC) with a level shifter circuit are disclosed. A level shifter circuit with input and output terminals is operable to shift an input signal that ranges from a ground voltage to a first positive voltage to an output signal that ranges from the ground voltage to a second positive voltage. The level shifter circuit further includes a first kicker transistor having a first source-drain terminal operable to receive a buffered version of the input signal and having a second source-drain terminal coupled to the output terminal. The first kicker transistor may receive gate signals that turn on the first kicker transistor when the input signal is at the ground voltage and may pull the output terminal to the first positive voltage as the input signal transitions from the ground voltage to the first positive voltage.
    Type: Grant
    Filed: December 21, 2011
    Date of Patent: December 17, 2013
    Assignee: Altera Corporation
    Inventors: Xiaobao Wang, Chiakang Sung, Khai Nguyen, Bonnie I. Wang
  • Publication number: 20130285725
    Abstract: Integrated circuits with clock generation and distribution circuitry are provided. Integrated circuits may include phase-locked loops configured to generate multiple clock signals that are delayed versions of one another. The clocks signal may be distributed to various regions on an integrated circuit using serially connected clock buffer blocks. Each buffer block may include bidirectional pairs of buffer circuits coupled in parallel. Each buffer circuit may have a first input configured to receive an input clock signal, an output at which a corrected version of the input clock signal is provided (e.g., an output at which an output clock signal with desired duty cycle is provided), a second input that receives a first delayed clock signal for setting the desired duty cycle for the output clock signal, and a third input that receives a second delayed clock signal that is high at least when the first delayed clock signal rises high.
    Type: Application
    Filed: June 28, 2013
    Publication date: October 31, 2013
    Inventors: John Henry Bui, Lay Hock Khoo, Khai Nguyen, Chiakang Sung, Ket Chiew Sia
  • Patent number: 8531205
    Abstract: One embodiment relates to a programmable output buffer which includes first and second programmable variable-impedance single-ended driver circuits and first and second termination circuits. The first termination circuit is coupled to a first output pin which is driven by the first programmable variable-impedance single-ended driver circuit, and the second termination circuit is coupled to a second output pin which is driven by the second programmable variable-impedance single-ended driver circuit. The first and second termination circuits are programmable to either provide parallel termination for a differential signal or drive single-ended signals with the parallel termination turned off. Other embodiments and features are also disclosed.
    Type: Grant
    Filed: January 31, 2012
    Date of Patent: September 10, 2013
    Assignee: Altera Corporation
    Inventors: Bonnie I. Wang, Chiakang Sung, Xiaobao Wang, Khai Nguyen, Joseph Huang
  • Patent number: 8487665
    Abstract: Methods and apparatus for providing either high-speed, or lower-speed, flexible inputs and outputs. An input and output structure having a high-speed input, a high-speed output, a low or moderate speed input, and an low or moderate speed output is provided. One of the input and output circuits are selected and the others are deselected. The high-speed input and output circuits are comparatively simple, in one example having only a clear signal for a control line input, and are able to interface to lower speed circuitry inside the core of an integrated circuit. The low or moderate speed input and output circuits are more flexible, for example, having preset, enable, and clear as control line inputs, and are able to support JTAG boundary testing. These parallel high and lower speed circuits are user selectable such that the input output structure is optimized between speed and functionality depending on the requirements of the application.
    Type: Grant
    Filed: May 31, 2011
    Date of Patent: July 16, 2013
    Assignee: Altera Corporation
    Inventors: Bonnie I. Wang, Chiakang Sung, Joseph Huang, Khai Nguyen, Philip Pan
  • Patent number: 8476947
    Abstract: Integrated circuits with clock generation and distribution circuitry are provided. Integrated circuits may include phase-locked loops configured to generate multiple clock signals that are delayed versions of one another. The clocks signal may be distributed to various regions on an integrated circuit using serially connected clock buffer blocks. Each buffer block may include bidirectional pairs of buffer circuits coupled in parallel. Each buffer circuit may have a first input configured to receive an input clock signal, an output at which a corrected version of the input clock signal is provided (e.g., an output at which an output clock signal with desired duty cycle is provided), a second input that receives a first delayed clock signal for setting the desired duty cycle for the output clock signal, and a third input that receives a second delayed clock signal that is high at least when the first delayed clock signal rises high.
    Type: Grant
    Filed: November 14, 2011
    Date of Patent: July 2, 2013
    Assignee: Altera Corporation
    Inventors: John Henry Bui, Lay Hock Khoo, Khai Nguyen, Chiakang Sung, Ket Chiew Sia
  • Publication number: 20130120044
    Abstract: Integrated circuits with clock generation and distribution circuitry are provided. Integrated circuits may include phase-locked loops configured to generate multiple clock signals that are delayed versions of one another. The clocks signal may be distributed to various regions on an integrated circuit using serially connected clock buffer blocks. Each buffer block may include bidirectional pairs of buffer circuits coupled in parallel. Each buffer circuit may have a first input configured to receive an input clock signal, an output at which a corrected version of the input clock signal is provided (e.g., an output at which an output clock signal with desired duty cycle is provided), a second input that receives a first delayed clock signal for setting the desired duty cycle for the output clock signal, and a third input that receives a second delayed clock signal that is high at least when the first delayed clock signal rises high.
    Type: Application
    Filed: November 14, 2011
    Publication date: May 16, 2013
    Inventors: John Henry Bui, Lay Hock Khoo, Khai Nguyen, Chiakang Sung, Ket Chiew Sia
  • Patent number: 8400186
    Abstract: A circuit comprises first and second differential pairs and first and second switch circuits. The first differential pair includes first and second transistors operable to generate a first output signal based on a first input signal in a single-ended mode. The second differential pair includes third and fourth transistors operable to generate a second output signal based on a second input signal in the single-ended mode. The first switch circuit is operable to block current through the second transistor in a differential mode. The second switch circuit is operable to block current through the third transistor in the differential mode. The first and the fourth transistors are operable to generate a third output signal based on a third input signal in the differential mode.
    Type: Grant
    Filed: February 21, 2012
    Date of Patent: March 19, 2013
    Assignee: Altera Corporation
    Inventors: Xiaobao Wang, Chiakang Sung, Joseph Huang, Khai Nguyen
  • Patent number: 8390315
    Abstract: Circuits and techniques for operating an integrated circuit (IC) with a configurable input-output circuit are disclosed. A disclosed circuit includes a single-ended input-output buffer coupled to an output terminal. The single-ended input-output buffer is operable to transmit an input signal to the output terminal as an output signal. A pre-emphasis circuit that is operable to sharpen a first edge and a second edge of the output signal is coupled between the single-ended input-output buffer and the output terminal. The first edge of the output signal is sharpened when the input signal switches from a first logic level to a second logic level while the second edge of the output signal is sharpened when the input signal switches from the second logic level to the first logic level.
    Type: Grant
    Filed: January 20, 2012
    Date of Patent: March 5, 2013
    Assignee: Altera Corporation
    Inventors: Xiaobao Wang, Chiakang Sung, Joseph Huang, Khai Nguyen
  • Patent number: 8384460
    Abstract: An adjustable delay circuit includes first and second transistors each having a control input coupled to an input node of the adjustable delay circuit and an output coupled to an output node of the adjustable delay circuit. The adjustable delay circuit includes a first pass gate coupled between first and second capacitors and the output node of the adjustable delay circuit. The first and the second capacitors are coupled between a node at a high voltage and a node at a low voltage. The first pass gate is operable to be controlled by a first delay control signal.
    Type: Grant
    Filed: March 14, 2012
    Date of Patent: February 26, 2013
    Assignee: Altera Corporation
    Inventors: Chiakang Sung, John Henry Bui, Khai Nguyen, Bonnie I. Wang, Xiaobao Wang
  • Patent number: 8368449
    Abstract: A circuit includes a phase adjustment circuit and a dead zone detect circuit. The phase adjustment circuit is operable to receive periodic signals and is operable to provide one of the periodic signals as a selected periodic signal based on a phase comparison between a data signal and the selected periodic signal. Each of the periodic signals has a different phase. The dead zone detect circuit is operable to cause the phase adjustment circuit to shift a phase of the selected periodic signal if the dead zone detect circuit determines that the data signal is in a dead zone. The dead zone detect circuit defines the dead zone based on two of the periodic signals. The phase adjustment circuit is operable to adjust a phase range of the dead zone.
    Type: Grant
    Filed: July 9, 2011
    Date of Patent: February 5, 2013
    Assignee: Altera Corporation
    Inventors: John Bui, Chiakang Sung, Khai Nguyen
  • Patent number: 8149038
    Abstract: A dynamic phase alignment circuit includes a phase generator circuit having delay-locked loop circuits that generate periodic output signals. Each of the delay-locked loop circuits generates one of the periodic output signals in response to at least two periodic input signals. A multiplexer circuit selects a selected periodic signal from among the periodic input signals and the periodic output signals based on select signals. A phase detection circuit compares a phase of the selected periodic signal to a data signal to generate a phase detection signal. A control logic circuit generates the select signals. The control logic circuit adjusts the select signals based on changes in the phase detection signal to cause the multiplexer circuit to adjust the phase of the selected periodic signal.
    Type: Grant
    Filed: March 22, 2010
    Date of Patent: April 3, 2012
    Assignee: Altera Corporation
    Inventors: Chiakang Sung, John Henry Bui, Khai Nguyen, Bonnie I. Wang, Xiaobao Wang
  • Publication number: 20110227606
    Abstract: Methods and apparatus for providing either high-speed, or lower-speed, flexible inputs and outputs. An input and output structure having a high-speed input, a high-speed output, a low or moderate speed input, and an low or moderate speed output is provided. One of the input and output circuits are selected and the others are deselected. The high-speed input and output circuits are comparatively simple, in one example having only a clear signal for a control line input, and are able to interface to lower speed circuitry inside the core of an integrated circuit. The low or moderate speed input and output circuits are more flexible, for example, having preset, enable, and clear as control line inputs, and are able to support JTAG boundary testing. These parallel high and lower speed circuits are user selectable such that the input output structure is optimized between speed and functionality depending on the requirements of the application.
    Type: Application
    Filed: May 31, 2011
    Publication date: September 22, 2011
    Applicant: ALTERA CORPORATION
    Inventors: Bonnie I. Wang, Chiakang Sung, Joseph Huang, Khai Nguyen, Philip Pan
  • Patent number: 7994821
    Abstract: A level shifter circuit includes first and second transistors coupled in series and third and fourth transistors coupled in series. The fourth transistor is coupled to a first node between the first and the second transistors. The level shifter circuit also includes fifth and sixth transistors coupled in series and seventh and eighth transistors coupled in series. The eighth transistor is coupled to a second node between the fifth and the sixth transistors. The second and the eighth transistors receive a first input signal at control inputs. The fourth and the sixth transistors receive a second input signal at control inputs. The second input signal is inverted relative to the first input signal.
    Type: Grant
    Filed: April 2, 2010
    Date of Patent: August 9, 2011
    Assignee: Altera Corporation
    Inventors: Xiaobao Wang, Chiakang Sung, Khai Nguyen