Patents by Inventor Steven G. Check

Steven G. Check 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: 4829268
    Abstract: A loop filter for a phase locked loop system having a voltage controlled oscillator (VCO), a divide-by-N circuit responsive to the output of the VCO, and an edge sensitive phase/frequency comparator responsive to the output of the divide-by-N circuit and a reference timing signal for providing a first control signal when the output of the divide-by-N circuit lags the reference timing signal or a second control signal when the output of the divide-by-N circuit leads the reference signal. The loop filter specifically includes first and second capacitors serially coupled between an output node and a ground reference node, wherein the second capacitor is connected to the ground reference node and the output node provides a control voltage to the VCO. A first current source is controllably connected by a first switch to the output node in response to the first control signal, whereby the first current source charges the first and second serially coupled capacitors.
    Type: Grant
    Filed: May 12, 1988
    Date of Patent: May 9, 1989
    Assignee: Hughes Aircraft Company
    Inventors: Oskar N. Leuthold, Steven G. Check