Patents by Inventor Dean Liu

Dean Liu 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).

  • Publication number: 20030154447
    Abstract: A method for optimizing loop bandwidth in a delay locked loop is provided. A representative power supply waveform having noise is input into a simulation of the delay locked loop; an estimate of jitter is determined; and the loop bandwidth of the delay looked loop is adjusted until the jitter falls below a pre-selected value. Further, a computer system for optimizing loop bandwidth in a delay locked loop is provided. Further, a computer-readable medium having recorded thereon instructions adapted to optimize loop bandwidth in a delay locked loop is provided.
    Type: Application
    Filed: February 14, 2002
    Publication date: August 14, 2003
    Inventors: Claude Gauthier, Brian Amick, Dean Liu, Pradeep Trivedi
  • Publication number: 20030154048
    Abstract: A method for optimizing a decoupling capacitance for an on-chip temperature sensor is provided. A representative power supply waveform having noise is input into a simulation of the on-chip temperature sensor; a difference between a temperature representative input and a temperature dependent output of the on-chip temperature sensor is determined; and an amount of the decoupling capacitance is adjusted until the difference falls below a pre-selected value. A computer system for optimizing a decoupling capacitance for an on-chip temperature sensor is also provided. A computer-readable medium having recorded thereon instructions executable by a processor for optimizing a decoupling capacitance for an on-chip temperature sensor is further provided.
    Type: Application
    Filed: February 14, 2002
    Publication date: August 14, 2003
    Inventors: Brian Amick, Claude Gauthier, Pradeep Trivedi, Dean Liu
  • Publication number: 20030154064
    Abstract: A method for optimizing decoupling capacitance in a phase locked loop is provided. A representative power supply waveform having noise is input into a simulation of the phase locked loop; an estimate of jitter is determined; and an amount of the decoupling capacitance is adjusted until the jitter falls below a pre-selected value. Further, a computer system for optimizing decoupling capacitance in a phase locked loop is provided. Further, a computer-readable medium having recorded thereon instructions adapted to optimize decoupling capacitance in a phase locked loop is provided.
    Type: Application
    Filed: February 14, 2002
    Publication date: August 14, 2003
    Inventors: Claude Gauthier, Brian Amick, Dean Liu, Pradeep Trivedi
  • Publication number: 20030154065
    Abstract: A method for optimizing decoupling capacitance in a delay locked loop is provided. A representative power supply waveform having noise is input into a simulation of the delay locked loop; an estimate of jitter is determined; and an amount of the decoupling capacitance is adjusted until the jitter falls below a pre-selected value. Further, a computer system for optimizing decoupling capacitance in a delay locked loop is provided. Further, a computer-readable medium having recorded thereon instructions adapted to optimize decoupling capacitance in a delay locked loop is provided.
    Type: Application
    Filed: February 14, 2002
    Publication date: August 14, 2003
    Inventors: Claude Gauthier, Brian Amick, Dean Liu, Pradeep Trivedi
  • Publication number: 20030151464
    Abstract: A method for estimating jitter in a phase locked loop is provided. The estimation is determined from a simulation that uses a representative power supply waveform having noise as an input. Further, a computer system for estimating jitter in a phase locked loop is provided. Further, a computer-readable medium having recorded thereon instructions adapted to estimate jitter in a phase locked loop is provided.
    Type: Application
    Filed: February 14, 2002
    Publication date: August 14, 2003
    Inventors: Claude Gauthier, Brian Amick, Dean Liu, Pradeep Trivedi
  • Publication number: 20030154453
    Abstract: A method for optimizing loop bandwidth in a phase locked loop is provided. A representative power supply waveform having noise is input into a simulation of the phase locked loop; an estimate of jitter is determined; and the loop bandwidth of the phase looked loop is adjusted until the jitter falls below a pre-selected value. Further, a computer system for optimizing loop bandwidth in a phase locked loop is provided. Further, a computer-readable medium having recorded thereon instructions adapted to optimize loop bandwidth in a phase locked loop is provided.
    Type: Application
    Filed: February 14, 2002
    Publication date: August 14, 2003
    Inventors: Claude Gauthier, Brian Amick, Dean Liu, Pradeep Trivedi
  • Patent number: 6597218
    Abstract: A technique Readjusting a bias-generator in a delay locked loop after fabrication of the delay locked loop. The technique involves use of an adjustment circuit operatively connected to the bias-generator, where the adjustment circuit is controllable to facilitate a modification of a voltage output by the bias-generator. Such control of the voltage output by the bias-generator allows a designer to achieve a desired delay locked loop performance characteristic after the delay locked loop has been fabricated.
    Type: Grant
    Filed: April 24, 2002
    Date of Patent: July 22, 2003
    Assignee: Sun Microsystems, Inc.
    Inventors: Claude Gauthier, Brian Amick, Dean Liu, Pradeep Trivedi
  • Patent number: 6597219
    Abstract: A delay locked loop design that uses a switch operatively connected to a loop filter capacitor to control a leakage current of the loop filter capacitor is provided. By positioning a switch in series with the loop filter capacitor, the leakage current of the loop filter capacitor may be controlled by switching the switch ‘on’ when a charge pump of the delay locked loop is ‘on’ and switching the switch ‘off’ when the charge pump is ‘off,’ thereby cumulatively reducing the leakage current of the loop filter capacitor throughput the operation of the delay locked loop. Control and reduction of the loop filter capacitor leakage current leads to more reliable and stable delay locked loop behavior.
    Type: Grant
    Filed: July 19, 2002
    Date of Patent: July 22, 2003
    Assignee: Sun Microsystems, Inc.
    Inventors: Pradeep Trivedi, Claude R. Gauthier, Dean Liu
  • Publication number: 20030132790
    Abstract: A delay locked loop that uses a differential push/pull buffer is provided. The differential push/pull buffer of the DLL is used to create a buffered output that closely follows the characteristics of the buffer's input over a range of temperature, power supply noise operating conditions, and process (manufacturing) variations. Further, an integrated circuit that contains a delay locked loop that uses a differential push/pull buffer is provided. Further, a delay locked loop with means for buffering a delayed signal is provided. Further, a method for buffering a delayed clock signal using a differential push/pull buffer is provided.
    Type: Application
    Filed: January 11, 2002
    Publication date: July 17, 2003
    Inventors: Brian Amick, Claude Gauthier, Dean Liu
  • Patent number: 6593784
    Abstract: A technique for adjusting a bias-generator in a phase locked loop after fabrication of the phase locked loop is provided. The technique involves use of an adjustment circuit operatively connected to the bias-generator, where the adjustment circuit is controllable to facilitate a modification of a voltage output by the bias-generator. Such control of the voltage output by the bias-generator allows a designer to achieve a desired phase locked loop performance characteristic after the phase locked loop has been fabricated.
    Type: Grant
    Filed: April 24, 2002
    Date of Patent: July 15, 2003
    Assignee: Sun Microsystems, Inc.
    Inventors: Claude Gauthier, Brian Amick, Pradeep Trivedi, Dean Liu
  • Patent number: 6573770
    Abstract: A method and apparatus for post-fabrication adjustment of a delay locked loop leakage current is provided. The adjustment system includes an adjustment circuit that adjusts a leakage current offset circuit to compensate for the leakage current of a capacitor in the delay locked loop. The capacitor connects to a control voltage of the delay locked loop. Such control of the leakage current in the delay locked loop allows a designer to achieve a desired delay locked loop operating characteristic after the delay locked loop has been fabricated.
    Type: Grant
    Filed: August 29, 2002
    Date of Patent: June 3, 2003
    Assignee: Sun Microsystems, Inc.
    Inventors: Claude R. Gauthier, Pradeep R. Trivedi, Brian W. Amick, Dean Liu
  • Publication number: 20030098510
    Abstract: A current crowding reduction technique involving the uniform displacement of vias around a bump is provided. By uniformly arranging vias around the bump on an integrated circuit, current can uniformly flow to and from the bump, effectively leading to reduced current density around the bump. Further, a method for reducing current crowding around a bump using an uniform arrangement of vias around the bump is provided.
    Type: Application
    Filed: November 27, 2001
    Publication date: May 29, 2003
    Inventors: Pradeep Trivedi, Tyler Thorp, Sudhakar Bobba, Dean Liu
  • Publication number: 20030098508
    Abstract: A 120 degree bump placement layout for an integrated circuit power grid is provided. This layout improves integrated circuit performance and reliability and gives an integrated circuit designer added flexibility and uniformity in designing the integrated circuit. Further, a patterned bump array for a top metal layer of an integrated circuit having a plurality of 120 degree bump placement structures is provided.
    Type: Application
    Filed: November 29, 2001
    Publication date: May 29, 2003
    Inventors: Sudhakar Bobba, Tyler Thorp, Dean Liu
  • Publication number: 20030098512
    Abstract: A 150 degree bump placement layout for an integrated circuit power grid is provided. This layout improves integrated circuit performance and reliability and gives an integrated circuit designer added flexibility and uniformity in designing the integrated circuit. Further, a patterned bump array for a top metal layer of an integrated circuit having a plurality of 150 degree bump placement structures is provided.
    Type: Application
    Filed: November 29, 2001
    Publication date: May 29, 2003
    Inventors: Sudhakar Bobba, Tyler Thorp, Dean Liu, Pradeep Trivedi
  • Patent number: 6570420
    Abstract: A method and apparatus for post-fabrication adjustment of a delay locked loop leakage current is provided. The adjustment system includes a programmable current source that adjusts a leakage current offset circuit to compensate for the leakage current of a capacitor. The capacitor connects to a control voltage of the delay locked loop. The programmable current source includes at least one current source and switch to adjust the leakage current offset circuit. The programmable current source is selectively adjusted by a combinational logic circuit. Such control of the leakage current in the delay locked loop allows a designer to achieve a desired delay locked loop operating characteristic after fabrication of the adjustable delay locked loop.
    Type: Grant
    Filed: August 29, 2002
    Date of Patent: May 27, 2003
    Assignee: Sun Microsystems, Inc.
    Inventors: Pradeep R. Trivedi, Claude R. Gauthier, Dean Liu
  • Patent number: 6566758
    Abstract: A current crowding reduction technique involving the uniform displacement of vias around a bump is provided. By uniformly arranging vias around the bump on an integrated circuit, current can uniformly flow to and from the bump, effectively leading to reduced current density around the bump. Further, a method for reducing current crowding around a bump using an uniform arrangement of vias around the bump is provided.
    Type: Grant
    Filed: November 27, 2001
    Date of Patent: May 20, 2003
    Assignee: Sun Microsystems, Inc.
    Inventors: Pradeep Trivedi, Tyler Thorp, Sudhakar Bobba, Dean Liu
  • Patent number: 6556041
    Abstract: A method for reducing voltage variation in a PECL based component has been developed. The method includes powering up a PECL based component, such as a receiver circuit for a PLL, and activating or inserting a shunting resistance across the power supply terminals of a PECL power supply. The shunting resistance is inserted in parallel with the PECL based component, and is controllable such that the resistance can be selectively switched ‘on’ and/or ‘off.
    Type: Grant
    Filed: October 16, 2001
    Date of Patent: April 29, 2003
    Assignee: Sun Microsystems, Inc.
    Inventors: Claude R. Gauthier, Pradeep R. Trivedi, Dean Liu, Brian Amick
  • Publication number: 20030071650
    Abstract: A method for reducing voltage variation in a PECL based component has been developed. The method includes powering up a PECL based component, such as a receiver circuit for a PLL, and activating or inserting a shunting resistance across the power supply terminals of a PECL power supply. The shunting resistance is inserted in parallel with the PECL based component, and is controllable such that the resistance can be selectively switched ‘on’ and/or ‘off.
    Type: Application
    Filed: October 16, 2001
    Publication date: April 17, 2003
    Inventors: Claude R. Gauthier, Pradeep R. Trivedi, Dean Liu, Brian Amick
  • Publication number: 20030071669
    Abstract: A method for reducing global clock skew by referencing a first point on an integrated circuit to which to align other points on the integrated circuit is provided. Further, an integrated circuit that has localized DLLs having adjustable buffers that selectively drive a signal on a clock grid is provided. Further, a technique for using a local DLL, one or more phase detectors, and one or more DLLs connected to portions of a clock grid to reduce clock skew is provided.
    Type: Application
    Filed: October 11, 2001
    Publication date: April 17, 2003
    Inventors: Dean Liu, Tyler J. Thorp, Pradeep R. Trivedi, Gin S. Yee, Claude R. Gauthier
  • Publication number: 20030071667
    Abstract: A method for reducing voltage variation in the power supply system of a phase locked loop has been developed. The method includes powering up a phase locked loop and activating or inserting a shunting resistance across the power supply terminals. The shunting resistance is inserted in parallel with the phase locked loop, and is controllable such that the resistance can be selectively switched ‘on’ and/or ‘off.
    Type: Application
    Filed: October 16, 2001
    Publication date: April 17, 2003
    Inventors: Claude R. Gauthier, Pradeap R. Trivedi, Dean Liu, Brian Amick