Patents by Inventor James Theodore Richmond

James Theodore Richmond 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: 8314462
    Abstract: A semiconductor device may include an insulating layer and a semiconductor electrode on the insulating layer. An area of increased electrical resistance may separate a contact area of the semiconductor electrode from an active area of the semiconductor electrode. In addition, a metal contact may be provided on the contact area of the semiconductor electrode opposite the insulating layer.
    Type: Grant
    Filed: July 28, 2009
    Date of Patent: November 20, 2012
    Assignee: Cree, Inc.
    Inventors: Brett Adam Hull, Sei-Hyung Ryu, James Theodore Richmond
  • Patent number: 8294507
    Abstract: An electronic device includes a wide bandgap thyristor having an anode, a cathode, and a gate terminal, and a wide bandgap bipolar transistor having a base, a collector, and an emitter terminal. The emitter terminal of the bipolar transistor is directly coupled to the anode terminal of the thyristor such that the bipolar transistor and the thyristor are connected in series. The bipolar transistor and the thyristor define a wide bandgap bipolar power switching device that is configured to switch between a nonconducting state and a conducting state that allows current flow between a first main terminal corresponding to the collector terminal of the bipolar transistor and a second main terminal corresponding to the cathode terminal of the thyristor responsive to application of a first control signal to the base terminal of the bipolar transistor and responsive to application of a second control signal to the gate terminal of the thyristor. Related control circuits are also discussed.
    Type: Grant
    Filed: May 8, 2009
    Date of Patent: October 23, 2012
    Assignee: Cree, Inc.
    Inventors: Qingchun Zhang, James Theodore Richmond, Robert J. Callanan
  • Patent number: 8193848
    Abstract: Semiconductor switching devices include a wide band-gap power transistor, a wide band-gap surge current transistor that coupled in parallel to the power transistor, and a wide band-gap driver transistor that is configured to drive the surge current transistor. Substantially all of the on-state output current of the semiconductor switching device flows through the channel of the power transistor when a drain-source voltage of the power transistor is within a first voltage range, which range may correspond, for example, to the drain-source voltages expected during normal operation. In contrast, the semiconductor switching device is further configured so that in the on-state the output current flows through both the surge current transistor and the channel of the power transistor when the drain-source voltage of the power transistor is within a second, higher voltage range.
    Type: Grant
    Filed: November 2, 2009
    Date of Patent: June 5, 2012
    Assignee: Cree, Inc.
    Inventors: Qingchun Zhang, James Theodore Richmond, Anant K. Agarwal, Sei-Hyung Ryu
  • Publication number: 20110024834
    Abstract: A semiconductor device may include an insulating layer and a semiconductor electrode on the insulating layer. An area of increased electrical resistance may separate a contact area of the semiconductor electrode from an active area of the semiconductor electrode. In addition, a metal contact may be provided on the contact area of the semiconductor electrode opposite the insulating layer.
    Type: Application
    Filed: July 28, 2009
    Publication date: February 3, 2011
    Inventors: Brett Adam Hull, Sei-Hyung Ryu, James Theodore Richmond
  • Publication number: 20100301929
    Abstract: Semiconductor switching devices include a wide band-gap power transistor, a wide band-gap surge current transistor that coupled in parallel to the power transistor, and a wide hand-gap driver transistor that is configured to drive the surge current transistor. Substantially all of the on-state output current of the semiconductor switching device flows through the channel of the power transistor when a drain-source voltage of the power transistor is within a first voltage range, which range may correspond, for example, to the drain-source voltages expected during normal operation. In contrast, the semiconductor switching device is further configured so that in the on-state the output current flows through both the surge current transistor and the channel of the power transistor when the drain-source voltage of the power transistor is within a second, higher voltage range.
    Type: Application
    Filed: November 2, 2009
    Publication date: December 2, 2010
    Inventors: Qingchun Zhang, James Theodore Richmond, Anant K. Agarwal, Sei-Hyung Ryu
  • Publication number: 20100283529
    Abstract: An electronic device includes a wide bandgap thyristor having an anode, a cathode, and a gate terminal, and a wide bandgap bipolar transistor having a base, a collector, and an emitter terminal. The emitter terminal of the bipolar transistor is directly coupled to the anode terminal of the thyristor such that the bipolar transistor and the thyristor are connected in series. The bipolar transistor and the thyristor define a wide bandgap bipolar power switching device that is configured to switch between a nonconducting state and a conducting state that allows current flow between a first main terminal corresponding to the collector terminal of the bipolar transistor and a second main terminal corresponding to the cathode terminal of the thyristor responsive to application of a first control signal to the base terminal of the bipolar transistor and responsive to application of a second control signal to the gate terminal of the thyristor. Related control circuits are also discussed.
    Type: Application
    Filed: May 8, 2009
    Publication date: November 11, 2010
    Inventors: Qingchun Zhang, James Theodore Richmond, Robert J. Callanan