Patents by Inventor Robert G. Wrathall

Robert G. Wrathall 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).

  • Method of forming electrostatic discharge protection device for integrated circuit
    Patent number: 5877534
    Abstract: An electrostatic discharge (ESD) device includes a pair of depletion mode MOSFETs connected drain-to-drain in a series path between an input terminal and an output terminal, the gate of each MOSFET being connected to its source. A first diode having a relatively high breakdown voltage is connected between ground and the common drain terminal of the MOSFETs, and a second diode having a relatively low breakdown voltage is connected between ground and the output terminal of the device. The second diode breaks down during a relatively low, long-lived voltage spike (in an automobile, sometimes referred to as a "load dump"), while the second MOSFET saturates, limiting the size of the current through the second diode. The first diode breaks down during a large voltage spike of short duration, such as occurs from an ESD.
    Type: Grant
    Filed: June 12, 1997
    Date of Patent: March 2, 1999
    Assignee: Siliconix incorporated
    Inventors: Richard K. Williams, Peter Hille, Robert G. Wrathall
  • Method for forming electrostatic discharge protection device for integrated circuit
    Patent number: 5677205
    Abstract: An electrostatic discharge (ESD) device includes a pair of depletion mode MOSFETs connected drain-to-drain in a series path between an input terminal and an output terminal, the gate of each MOSFET being connected to its source. A first diode having a relatively high breakdown voltage is connected between ground and the common drain terminal of the MOSFETs, and a second diode having a relatively low breakdown voltage is connected between ground and the output terminal of the device. The second diode breaks down during a relatively low, long-lived voltage spike (in an automobile, sometimes referred to as a "load dump"), while the second MOSFET saturates, limiting the size of the current through the second diode. The first diode breaks down during a large voltage spike of short duration, such as occurs from an ESD.
    Type: Grant
    Filed: June 6, 1995
    Date of Patent: October 14, 1997
    Assignee: Siliconix incorporated
    Inventors: Richard K. Williams, Peter Hille, Robert G. Wrathall
  • Electrostatic discharge protection device for integrated circuit
    Patent number: 5654574
    Abstract: An electrostatic discharge (ESD) device includes a pair of depletion mode MOSFETs connected drain-to-drain in a series path between an input terminal and an output terminal, the gate of each MOSFET being connected to its source. A first diode having a relatively high breakdown voltage is connected between ground and the common drain terminal of the MOSFETs, and a second diode having a relatively low breakdown voltage is connected between ground and the output terminal of the device. The second diode breaks down during a relatively low, long-lived voltage spike (in an automobile, sometimes referred to as a "load dump"), while the second MOSFET saturates, limiting the size of the current through the second diode. The first diode breaks down during a large voltage spike of short duration, such as occurs from an ESD.
    Type: Grant
    Filed: June 6, 1995
    Date of Patent: August 5, 1997
    Assignee: Siliconix incorporated
    Inventors: Richard K. Williams, Peter Hille, Robert G. Wrathall
  • Electrostatic discharge protection device for integrated circuit
    Patent number: 5545909
    Abstract: An electrostatic discharge (ESD) device includes a pair of depletion mode MOSFETs connected drain-to-drain in a series path between an input terminal and an output terminal, the gate of each MOSFET being connected to its source. A first diode having a relatively high breakdown voltage is connected between ground and the common drain terminal of the MOSFETs, and a second diode having a relatively low breakdown voltage is connected between ground and the output terminal of the device. The second diode breaks down during a relatively low, long-lived voltage spike (in an automobile, sometimes referred to as a "load dump"), while the second MOSFET saturates, limiting the size of the current through the second diode. The first diode breaks down during a large voltage spike of short duration, such as occurs from an ESD.
    Type: Grant
    Filed: October 19, 1994
    Date of Patent: August 13, 1996
    Assignee: Siliconix incorporated
    Inventors: Richard K. Williams, Peter Hille, Robert G. Wrathall