Patents by Inventor Sivakumar Sivasothy

Sivakumar Sivasothy 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).

  • Fast switching circuit for lateral PNP transistors
    Patent number: 4644186
    Abstract: A circuit (100) is shown which provides a large turn-on current drive to the base of a lateral PNP transistor (218) by forcing a large voltage drop across the base-emitter junction of the lateral PNP transistor in order to quickly turn on the PNP transistor. A current sensing circuit (203, 166) determines when the collector current in the PNP transistor is sufficient for proper operation of the rest of the circuitry dependent upon this PNP transistor. The current sensing circuitry then limits the base drive applied to the PNP transistor to the current level necessary to maintain the required quiescent collector current in the PNP transistor. In addition, means (190, 200) are provided to quickly clamp the base of the PNP transistor to the emitter of the PNP transistor thereby quickly turning off the PNP transistor.
    Type: Grant
    Filed: August 20, 1984
    Date of Patent: February 17, 1987
    Assignee: National Semiconductor Corporation
    Inventors: Sivakumar Sivasothy, Ramanatha V. Balakrishnan