Patents by Inventor Carl Wilmer Thatcher

Carl Wilmer Thatcher 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).

  • Method and apparatus for testing integrated circuits in a mixed-signal environment
    Patent number: 5968191
    Abstract: A method and apparatus is disclosed for testing integrated circuit interconnect and measuring the value of passive component interconnecting the IC's. Each IC includes both analog and digital circuitry and is provided with a test access port and boundary scan architecture for selectively connecting components to an analog test bus and for testing for the integrity of interconnections. When connected with the test bus, a constant current is supplied to the component and the resulting voltage developed across the bus is used for identifying the value of the component. In a second embodiment each IC includes a pair of buses which permits measurement of the impedance of the switches connecting the components to the test bus.
    Type: Grant
    Filed: April 28, 1997
    Date of Patent: October 19, 1999
    Assignees: Hewlett-Packard Company, Ford Motor Company
    Inventors: Carl Wilmer Thatcher, Stig Herman Oresjo, John Elliott McDermid, Kenneth Paul Parker