Patents by Inventor John Paul Norsworthy

John Paul Norsworthy 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: 5748127
    Abstract: A precise current cell for a digital-to-analog (D/A) convertor circuit is designed to compensate for manufacturing process variations. The cell uses a cascoded transistor chain to control the output voltage and isolate voltage supply noise. An external (off-chip) bias current is fed into a cascoded biasing string of eight transistors, which are further mirrored to the current cell itself. The biasing scheme accounts for manufacturing process variations in the chip, which leads to very precise current being replicated at the output of the D/A circuit. Current steering and an improved shunt path within the current cell minimizes voltage swings during switching of the current cell. This allows for faster switching of the cell while minimizing noise coupling due to the voltage swings. The current cell also has an associated biasing stage. This biasing stage allows for improved matching within the current cell, resulting in improved accuracy of conversion.
    Type: Grant
    Filed: December 22, 1995
    Date of Patent: May 5, 1998
    Assignee: Cirrus Logic, Inc.
    Inventors: Jaideep Prakash, John Paul Norsworthy, Bruce Andrew Doyle