Patents by Inventor Willam D. Llewellyn

Willam D. Llewellyn 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).

  • PNP transistor base drive compensation circuit
    Patent number: 5157322
    Abstract: In an integrated circuit a PNP current mirror can lose its current reflection accuracy when low Beta transistors are involved. Since the conventional PNP transistors can often have low Beta this can become a serious problem particularly with high current gain plural output current mirrors. In the invention a compensation current is fed to the current mirror to increase the PNP transistor base currents as an inverse function of Beta. Several alternative circuit embodiments are also disclosed.
    Type: Grant
    Filed: August 13, 1991
    Date of Patent: October 20, 1992
    Assignee: National Semiconductor Corporation
    Inventor: Willam D. Llewellyn