Patents by Inventor John A. Fitfield

John A. Fitfield 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: 6879021
    Abstract: An antifuse device (120) that includes a bias element (124) and an programmable antifuse element (128) arranged in series with one another so as to form a voltage divider having an output node (F) located between the bias and antifuse elements. When the antifuse device is in its unprogrammed state, each of the bias element and antifuse element is non-conductive. When the antifuse device is in its programmed state, the bias element remains non-conductive, but the antifuse element is conductive. The difference in the resistance of the antifuse element between its unprogrammed state and programmed state causes the difference in voltages seen at the output node to be on the order of hundreds of mili-volts when a voltage of 1 V is applied across the antifuse device. This voltage difference is so high that it can be readily sensed using a simple sensing circuit (228).
    Type: Grant
    Filed: October 6, 2003
    Date of Patent: April 12, 2005
    Assignee: International Business Machines Corporation
    Inventors: John A. Fitfield, Wagdi W. Abadeer, William R. Tonti