Patents by Inventor Thomas Parrish

Thomas Parrish 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: 4097753
    Abstract: A comparator circuit for comparing two voltage levels in a C-2C A/D and D/A converter, comprising four cross-coupled active devices (FETs) in a latch arrangement whereby an offset voltage is used to compensate for imbalances in the comparator. The comparator includes a first FET having its gate electrode connected to the output of the D/A converter, and a second FET having its gate electrode connected to an analog input voltage. The first and second FETs each have one of their electrodes connected to a common voltage source. A third and a fourth FET have one of their electrodes connected respectively to the other electrode of the first and second FETs at first and second common nodes, respectively. The output of the comparator is provided at one of such first and second common nodes. The first and second nodes are also respectively connected to the gate electrodes of the fourth and third FETs in a cross-coupled arrangement.
    Type: Grant
    Filed: April 2, 1976
    Date of Patent: June 27, 1978
    Assignee: International Business Machines Corporation
    Inventors: Peter William Cook, James Thomas Parrish, Stanley Everett Schuster
  • Patent number: D293840
    Type: Grant
    Filed: July 18, 1985
    Date of Patent: January 19, 1988
    Inventor: Thomas Parrish