Patents by Inventor Kent R. Callahan

Kent R. Callahan 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: 8255733
    Abstract: A method of providing a clock signal for an embodiment includes performing a calibration for a closed loop control system to determine a control signal value that provides a desired tuning of the closed loop control system. The control signal value is stored and provided to a delay circuit, wherein a delay range and a delay step size of the delay circuit is based on the control signal value. A delay select control signal is provided to the delay circuit to select a specific delay within the delay range.
    Type: Grant
    Filed: July 30, 2009
    Date of Patent: August 28, 2012
    Assignee: Lattice Semiconductor Corporation
    Inventors: Robert M. Bartel, Kent R. Callahan, Michael G. France
  • Patent number: 7663419
    Abstract: Systems and methods are disclosed herein to provide improved clock, delay, and skew techniques. For example, in accordance with an embodiment of the present invention, an integrated circuit includes a clock generator to provide a bias signal and a clock signal, with control logic providing a delay control signal based on the bias signal and a multi-bit control signal. A clock skew circuit provides a delay to the clock signal based on the delay control signal provided by the control signal. Memory coupled to the control logic provides the multi-bit control signal.
    Type: Grant
    Filed: November 19, 2008
    Date of Patent: February 16, 2010
    Assignee: Lattice Semiconductor Corporation
    Inventors: Kent R. Callahan, Robert M. Bartel
  • Patent number: 7456672
    Abstract: Systems and methods are disclosed herein to provide improved clock, delay, and skew techniques. For example, in accordance with an embodiment of the present invention, an integrated circuit includes a clock generator to provide a bias signal and a clock signal, with control logic providing a delay control signal based on the bias signal and the control signal. A delay circuit provides a delay to the clock signal based on the delay control signal.
    Type: Grant
    Filed: September 11, 2006
    Date of Patent: November 25, 2008
    Assignee: Lattice Semiconductor Corporation
    Inventors: Kent R. Callahan, Robert M. Bartel
  • Patent number: 6614317
    Abstract: A lock detector system which operates adaptively based on a frequency of operation. Different lock windows are defined for different frequencies of operation and are automatically formed based on the controlled signal that is used to drive the voltage controlled oscillator of the phase locked loop.
    Type: Grant
    Filed: May 24, 2001
    Date of Patent: September 2, 2003
    Assignee: Intel Corporation
    Inventors: Keng L. Wong, Usman Azeez Mughal, Masud Kamal, Chee How Lim, Kent R. Callahan
  • Patent number: 6531974
    Abstract: Controlling time delay includes using a delay line and a digital to analog converter configured to provide a signal to the delay line and including digital inputs configured to control the delay through the delay line by controlling amplifier gain elements included in the digital to analog converter.
    Type: Grant
    Filed: April 7, 2000
    Date of Patent: March 11, 2003
    Assignee: Intel Corporation
    Inventors: Kent R. Callahan, Keng L. Wong
  • Publication number: 20020175769
    Abstract: A lock detector system which operates adaptively based on a frequency of operation. Different lock windows are defined for different frequencies of operation and are automatically formed based on the controlled signal that is used to drive the voltage controlled oscillator of the phase locked loop.
    Type: Application
    Filed: May 24, 2001
    Publication date: November 28, 2002
    Inventors: Keng L. Wong, Usman Azeez Mughal, Masud Kamal, Chee How Lim, Kent R. Callahan
  • Patent number: 6208169
    Abstract: An apparatus and method for detecting and measuring internal clock jitter is disclosed. In one embodiment, a reference clock generator generates a reference clock signal based on an instantaneous clock signal. The reference clock signal includes the instantaneous clock signal delayed for an average duration. A phase comparing element receives both the instantaneous clock signal and the reference clock signal such that the phase comparing element measures a phase difference between the instantaneous clock signal and the reference clock signal. The magnitude and direction of the phase difference is indicated by one of a number of distinct phase difference bins in the phase comparing element.
    Type: Grant
    Filed: June 28, 1999
    Date of Patent: March 27, 2001
    Assignee: Intel Corporation
    Inventors: Keng L. Wong, Gregory F. Taylor, Ravishankar Kuppuswamy, Douglas R. Parker, Hung-Piao Ma, Kent R. Callahan, Xia Dai
  • Patent number: 5347278
    Abstract: A method for mapping the serial 0 and 1 pulses received at a known clock rate from a delta sigma modulator All 0's are generated at the output when no 11 pairs are present in the input signal during the sampled clock periods. A 1 is generated at the output responsive to the input signal and the input signal delayed by one clock period both being 1's when no 00 pairs are present in the input signal during the sampled clock periods. A 1 is generated at the output for each 11 pair not balanced by a 00 pair when 11 and 00 pairs are serially alternating in the input signal during the sampled clock periods. According to this mapping method, the pulse density of 1's in the output signal increases only responsive to an increase in the net number of 11 pairs in the input signal during the sampled clock periods. A circuit for implementing this pulse mapping method is also described.
    Type: Grant
    Filed: September 30, 1993
    Date of Patent: September 13, 1994
    Assignee: Ford Motor Company
    Inventors: Kent R. Callahan, Christopher J. Kemp
  • Patent number: 4344050
    Abstract: A switched capacitor filter is designed utilizing two parallel switched capacitor charge pumps. These two, parallel charge pumps operate out of phase with each other, thereby allowing charging of a storage capacitor at a rate equal to twice the clock frequency, thereby decreasing incremental voltage steps during the charging of the storage capacitor.
    Type: Grant
    Filed: September 22, 1980
    Date of Patent: August 10, 1982
    Assignee: American Microsystems, Inc.
    Inventor: Kent R. Callahan