Patents by Inventor Robert M. Bartel

Robert M. Bartel 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: 7969248
    Abstract: In one example, a method of tuning an oscillator of a phase-locked loop (PLL) circuit includes adjusting a coarse control signal to select one of a plurality of frequency tuning curves of the oscillator. The method includes adjusting a fine control signal to select a position on the selected frequency tuning curve. A frequency of the oscillator is determined by the coarse control signal and the fine control signal. The method includes attempting to detect a lock between a feedback signal and a reference signal. A frequency of the feedback signal is determined by the frequency of the oscillator. The method includes comparing the fine control signal to a reference value if the lock is detected. The method includes adjusting the coarse control signal to select a different one of the frequency tuning curves if the selected position on the selected frequency tuning curve is outside a desired tuning range.
    Type: Grant
    Filed: July 30, 2009
    Date of Patent: June 28, 2011
    Assignee: Lattice Semiconductor Corporation
    Inventors: Trent Whitten, Robert M. Bartel, 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: 7019584
    Abstract: A bandgap reference circuit can use various output stages to implement a controlled feedback method of sensing and supplying the needed load current through a sensing network. A small amount of circuitry can be added to a class AB output stage to decouple the bandgap reference feedback from a capacitive load and simultaneously sense load current needs and boost current as needed while minimizing voltage droop. Such circuits can be implemented using relatively compact designs while still reducing droop, and thus allowing the use of a large external capacitor to reduce noise and maintain good power supply rejection.
    Type: Grant
    Filed: January 30, 2004
    Date of Patent: March 28, 2006
    Assignee: Lattice Semiconductor Corporation
    Inventors: Robert M. Bartel, Joey I. Doernberg, Edward E. Miller
  • Patent number: 6981381
    Abstract: Device driver circuits based on H-bridges can be implemented to provide linear control of the H-bridge, reduce power losses, and reduce certain component size/cost. The driver circuits can use two feedback loops to operate the H-bridge in different regions and to guarantee that current flows through an H-bridge load device, such as a thermoelectric cooler, in only one direction at a given time. The H-bridge driver circuits can remove the possibility of high currents bypassing the load device and thus going directly through the switches on either side of the H-bridge driver. The H-bridge driver circuits also ensure careful control of the current applied to the H-bridge load device. Such driver circuits are particularly useful for controlling the current applied to thermoelectric devices.
    Type: Grant
    Filed: December 16, 2003
    Date of Patent: January 3, 2006
    Assignee: Lattice Semiconductor Corp.
    Inventors: Ching Wang, Robert M. Bartel, Hans W. Klein