Patents Assigned to Keystone Semiconductor, Inc.
  • Patent number: 7639048
    Abstract: A system and method for detecting a phase and a frequency and an arrival-time difference between two signals (118 and 120) that minimizes delay and jitter, and has stable operation even when the two signals (118 and 120) are essentially identical. The system includes two single-ended charge-pump (188), phase-frequency detection (PFD) circuits (280). The first PFD is stable when a reference signal, supplied to a polarity determining flip-flop, leads the signal to be synchronized. A second, complementary, PFD circuit is stable, but has an inverted polarity output, when the signal to be synchronized, supplied to a polarity determining flip-flop, leads the reference signal. A polarity-selection logic-circuit (284) ensures that the first activated PFD controls the polarity a single-ended charge pump (188) for a time-period determined by the delay between the activation of the polarity determining and non-polarity determining flip-flops of the selected PFD.
    Type: Grant
    Filed: July 28, 2005
    Date of Patent: December 29, 2009
    Assignee: Keystone Semiconductor, Inc.
    Inventor: Wen T. Lin
  • Publication number: 20090135885
    Abstract: This patent disclosure presents circuits, systems and methods to spread a clock signal to produce a random spreading for the clock signal that offers the maximum possible power density reduction for the spurious radiations generated from the clock signal and its harmonics. These new inventions utilize a non-linear feedback control loop to assist in generation of the spread spectrum clock and result in electronic products that can pass the FCC requirements for spurious radiations generated by the clock signal and its harmonics without utilizing expensive shielding and other EMI suppression methods.
    Type: Application
    Filed: November 7, 2006
    Publication date: May 28, 2009
    Applicant: KEYSTONE SEMICONDUCTOR, INC.
    Inventor: Wen T. Lin
  • Publication number: 20080175045
    Abstract: Positive logic circuits, systems and methods using MOSFETs operated in a depletion-mode, including electrostatic discharge protection circuits (ESD), non-inverting latches and buffers, and one-to-three transistor static random access memory cells. These novel circuits supplement enhancement-mode MOSFET technology and are also intended to improve the reliability of the complementary metal-oxide-semiconductor (CMOS) integrated circuit (IC) products.
    Type: Application
    Filed: January 24, 2008
    Publication date: July 24, 2008
    Applicant: KEYSTONE SEMICONDUCTOR, INC.
    Inventor: WEN T. LIN
  • Publication number: 20080150588
    Abstract: A system and method for detecting a phase and a frequency and an arrival-time difference between two signals (118 and 120) that minimizes delay and jitter, and has stable operation even when the two signals (118 and 120) are essentially identical. The system includes two single-ended charge-pump (188), phase-frequency detection (PFD) circuits (280). The first PFD is stable when a reference signal, supplied to a polarity determining flip-flop, leads the signal to be synchronized. A second, complementary, PFD circuit is stable, but has an inverted polarity output, when the signal to be synchronized, supplied to a polarity determining flip-flop, leads the reference signal. A polarity-selection logic-circuit (284) ensures that the first activated PFD controls the polarity a single-ended charge pump (188) for a time-period determined by the delay between the activation of the polarity determining and non-polarity determining flip-flops of the selected PFD.
    Type: Application
    Filed: July 28, 2005
    Publication date: June 26, 2008
    Applicant: KEystone Semiconductor, Inc.
    Inventor: Wen T. Lin