Patents by Inventor Subhas Chandra Bose Jayappa Veeramma

Subhas Chandra Bose Jayappa Veeramma 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: 10304970
    Abstract: In a first embodiment, an ultra-fast breakover diode has a turn on time TON that is less than 0.3 microseconds, where the forward breakover voltage is greater than +400 volts and varies less than one percent per ten degrees Celsius change. In a second embodiment, a breakover diode has a reverse breakdown voltage that is greater, in absolute magnitude, than the forward breakover voltage, where the forward breakover voltage is greater than +400 volts. In a third embodiment, a string of series-connected breakover diode dice is provided, along with a resistor string, in a packaged circuit. The packaged circuit acts like a single breakover diode having a large forward breakover voltage and a comparably large reverse breakdown voltage, even though the packaged circuit includes no discrete high voltage reverse breakdown diode. The packaged circuit is usable to supply a triggering current to a thyristor in a voltage protection circuit.
    Type: Grant
    Filed: January 20, 2018
    Date of Patent: May 28, 2019
    Assignee: IXYS, LLC
    Inventor: Subhas Chandra Bose Jayappa Veeramma
  • Publication number: 20180145186
    Abstract: In a first embodiment, an ultra-fast breakover diode has a turn on time TON that is less than 0.3 microseconds, where the forward breakover voltage is greater than +400 volts and varies less than one percent per ten degrees Celsius change. In a second embodiment, a breakover diode has a reverse breakdown voltage that is greater, in absolute magnitude, than the forward breakover voltage, where the forward breakover voltage is greater than +400 volts. In a third embodiment, a string of series-connected breakover diode dice is provided, along with a resistor string, in a packaged circuit. The packaged circuit acts like a single breakover diode having a large forward breakover voltage and a comparably large reverse breakdown voltage, even though the packaged circuit includes no discrete high voltage reverse breakdown diode. The packaged circuit is usable to supply a triggering current to a thyristor in a voltage protection circuit.
    Type: Application
    Filed: January 20, 2018
    Publication date: May 24, 2018
    Inventor: Subhas Chandra Bose Jayappa Veeramma
  • Patent number: 9935206
    Abstract: In a first embodiment, an ultra-fast breakover diode has a turn on time TON that is less than 0.3 microseconds, where the forward breakover voltage is greater than +400 volts and varies less than one percent per ten degrees Celsius change. In a second embodiment, a breakover diode has a reverse breakdown voltage that is greater, in absolute magnitude, than the forward breakover voltage, where the forward breakover voltage is greater than +400 volts. In a third embodiment, a string of series-connected breakover diode dice is provided, along with a resistor string, in a packaged circuit. The packaged circuit acts like a single breakover diode having a large forward breakover voltage and a comparably large reverse breakdown voltage, even though the packaged circuit includes no discrete high voltage reverse breakdown diode. The packaged circuit is usable to supply a triggering current to a thyristor in a voltage protection circuit.
    Type: Grant
    Filed: May 10, 2013
    Date of Patent: April 3, 2018
    Assignee: IXYS Corporation
    Inventor: Subhas Chandra Bose Jayappa Veeramma
  • Patent number: 9379203
    Abstract: An ultra-fast breakover diode has a turn on time TON that is less than 0.3 microseconds, where the forward breakover voltage is greater than +400 volts and varies less than one percent per ten degrees Celsius change. In another aspect of the invention, a breakover diode has a reverse breakdown voltage that is greater, in absolute magnitude, than the forward breakover voltage, where the forward breakover voltage is greater than +400 volts. Yet another aspect of the invention involves a string of series-connected breakover diode dice, along with a resistor string, in a packaged circuit. The packaged circuit acts like a single breakover diode having a large forward breakover voltage and a comparably large reverse breakdown voltage, even though the packaged circuit includes no discrete high voltage reverse breakdown diode. The packaged circuit is usable to supply a triggering current to a thyristor in a voltage protection circuit.
    Type: Grant
    Filed: June 6, 2015
    Date of Patent: June 28, 2016
    Assignee: IXYS Corporation
    Inventor: Subhas Chandra Bose Jayappa Veeramma
  • Publication number: 20150270370
    Abstract: An ultra-fast breakover diode has a turn on time TON that is less than 0.3 microseconds, where the forward breakover voltage is greater than +400 volts and varies less than one percent per ten degrees Celsius change. In another aspect of the invention, a breakover diode has a reverse breakdown voltage that is greater, in absolute magnitude, than the forward breakover voltage, where the forward breakover voltage is greater than +400 volts. Yet another aspect of the invention involves a string of series-connected breakover diode dice, along with a resistor string, in a packaged circuit. The packaged circuit acts like a single breakover diode having a large forward breakover voltage and a comparably large reverse breakdown voltage, even though the packaged circuit includes no discrete high voltage reverse breakdown diode. The packaged circuit is usable to supply a triggering current to a thyristor in a voltage protection circuit.
    Type: Application
    Filed: June 6, 2015
    Publication date: September 24, 2015
    Inventor: Subhas Chandra Bose Jayappa Veeramma
  • Patent number: 9087809
    Abstract: An ultra-fast breakover diode has a turn on time TON that is less than 0.3 microseconds, where the forward breakover voltage is greater than +400 volts and varies less than one percent per ten degrees Celsius change. In another aspect of the invention, a breakover diode has a reverse breakdown voltage that is greater, in absolute magnitude, than the forward breakover voltage, where the forward breakover voltage is greater than +400 volts. Yet another aspect of the invention involves a string of series-connected breakover diode dice, along with a resistor string, in a packaged circuit. The packaged circuit acts like a single breakover diode having a large forward breakover voltage and a comparably large reverse breakdown voltage, even though the packaged circuit includes no discrete high voltage reverse breakdown diode. The packaged circuit is usable to supply a triggering current to a thyristor in a voltage protection circuit.
    Type: Grant
    Filed: August 5, 2014
    Date of Patent: July 21, 2015
    Assignee: IXYS Corporation
    Inventor: Subhas Chandra Bose Jayappa Veeramma
  • Publication number: 20140346559
    Abstract: In a first embodiment, an ultra-fast breakover diode has a turn on time TON that is less than 0.3 microseconds, where the forward breakover voltage is greater than +400 volts and varies less than one percent per ten degrees Celsius change. In a second embodiment, a breakover diode has a reverse breakdown voltage that is greater, in absolute magnitude, than the forward breakover voltage, where the forward breakover voltage is greater than +400 volts. In a third embodiment, a string of series-connected breakover diode dice is provided, along with a resistor string, in a packaged circuit. The packaged circuit acts like a single breakover diode having a large forward breakover voltage and a comparably large reverse breakdown voltage, even though the packaged circuit includes no discrete high voltage reverse breakdown diode. The packaged circuit is usable to supply a triggering current to a thyristor in a voltage protection circuit.
    Type: Application
    Filed: August 5, 2014
    Publication date: November 27, 2014
    Inventor: Subhas Chandra Bose Jayappa Veeramma
  • Publication number: 20140332841
    Abstract: In a first embodiment, an ultra-fast breakover diode has a turn on time TON that is less than 0.3 microseconds, where the forward breakover voltage is greater than +400 volts and varies less than one percent per ten degrees Celsius change. In a second embodiment, a breakover diode has a reverse breakdown voltage that is greater, in absolute magnitude, than the forward breakover voltage, where the forward breakover voltage is greater than +400 volts. In a third embodiment, a string of series-connected breakover diode dice is provided, along with a resistor string, in a packaged circuit. The packaged circuit acts like a single breakover diode having a large forward breakover voltage and a comparably large reverse breakdown voltage, even though the packaged circuit includes no discrete high voltage reverse breakdown diode. The packaged circuit is usable to supply a triggering current to a thyristor in a voltage protection circuit.
    Type: Application
    Filed: May 10, 2013
    Publication date: November 13, 2014
    Applicant: IXYS Corporation
    Inventor: Subhas Chandra Bose Jayappa Veeramma
  • Publication number: 20140332842
    Abstract: In a first embodiment, an ultra-fast breakover diode has a turn on time TON that is less than 0.3 microseconds, where the forward breakover voltage is greater than +400 volts and varies less than one percent per ten degrees Celsius change. In a second embodiment, a breakover diode has a reverse breakdown voltage that is greater, in absolute magnitude, than the forward breakover voltage, where the forward breakover voltage is greater than +400 volts. In a third embodiment, a string of series-connected breakover diode dice is provided, along with a resistor string, in a packaged circuit. The packaged circuit acts like a single breakover diode having a large forward breakover voltage and a comparably large reverse breakdown voltage, even though the packaged circuit includes no discrete high voltage reverse breakdown diode. The packaged circuit is usable to supply a triggering current to a thyristor in a voltage protection circuit.
    Type: Application
    Filed: May 10, 2013
    Publication date: November 13, 2014
    Applicant: IXYS Corporation
    Inventor: Subhas Chandra Bose Jayappa Veeramma
  • Patent number: 8878236
    Abstract: In a first embodiment, an ultra-fast breakover diode has a turn on time TON that is less than 0.3 microseconds, where the forward breakover voltage is greater than +400 volts and varies less than one percent per ten degrees Celsius change. In a second embodiment, a breakover diode has a reverse breakdown voltage that is greater, in absolute magnitude, than the forward breakover voltage, where the forward breakover voltage is greater than +400 volts. In a third embodiment, a string of series-connected breakover diode dice is provided, along with a resistor string, in a packaged circuit. The packaged circuit acts like a single breakover diode having a large forward breakover voltage and a comparably large reverse breakdown voltage, even though the packaged circuit includes no discrete high voltage reverse breakdown diode. The packaged circuit is usable to supply a triggering current to a thyristor in a voltage protection circuit.
    Type: Grant
    Filed: May 10, 2013
    Date of Patent: November 4, 2014
    Assignee: IXYS Corporation
    Inventor: Subhas Chandra Bose Jayappa Veeramma
  • Patent number: 8836090
    Abstract: A power device (such as a power diode) has a peripheral die area and a central area. The main PN junction of the device is formed by a P+ type region that extends down into an N? type layer. The central portion of the P+ type region has a plurality of openings so mesa structures of the underlying N? type material extend up to the semiconductor surface through the openings. Due to the mesa structures being located in the central portion of the die, there are vertically extending extensions of the PN junction in the central portion of the die. Minority carrier charge storage is more uniform per unit area across the surface of the die. Due to the form of the P+ type region and the mesa structures, the reverse recovery of the PN junction exhibits a soft characteristic.
    Type: Grant
    Filed: March 1, 2013
    Date of Patent: September 16, 2014
    Assignee: IXYS Corporation
    Inventor: Subhas Chandra Bose Jayappa Veeramma
  • Patent number: 8835975
    Abstract: In a first embodiment, an ultra-fast breakover diode has a turn on time TON that is less than 0.3 microseconds, where the forward breakover voltage is greater than +400 volts and varies less than one percent per ten degrees Celsius change. In a second embodiment, a breakover diode has a reverse breakdown voltage that is greater, in absolute magnitude, than the forward breakover voltage, where the forward breakover voltage is greater than +400 volts. In a third embodiment, a string of series-connected breakover diode dice is provided, along with a resistor string, in a packaged circuit. The packaged circuit acts like a single breakover diode having a large forward breakover voltage and a comparably large reverse breakdown voltage, even though the packaged circuit includes no discrete high voltage reverse breakdown diode. The packaged circuit is usable to supply a triggering current to a thyristor in a voltage protection circuit.
    Type: Grant
    Filed: May 10, 2013
    Date of Patent: September 16, 2014
    Assignee: IXYS Corporation
    Inventor: Subhas Chandra Bose Jayappa Veeramma
  • Publication number: 20140246761
    Abstract: A power device (such as a power diode) has a peripheral die area and a central area. The main PN junction of the device is formed by a P+ type region that extends down into an N? type layer. The central portion of the P+ type region has a plurality of openings so mesa structures of the underlying N? type material extend up to the semiconductor surface through the openings. Due to the mesa structures being located in the central portion of the die, there are vertically extending extensions of the PN junction in the central portion of the die. Minority carrier charge storage is more uniform per unit area across the surface of the die. Due to the form of the P+ type region and the mesa structures, the reverse recovery of the PN junction exhibits a soft characteristic.
    Type: Application
    Filed: March 1, 2013
    Publication date: September 4, 2014
    Applicant: IXYS Corporation
    Inventor: Subhas Chandra Bose Jayappa Veeramma
  • Patent number: 8716745
    Abstract: A diode is defined on a die. The diode includes a substrate of P conductivity having an upper surface and a lower surface, the substrate having first and second ends corresponding to first and second edges of the die. An anode contacts the lower surface of the substrate. A layer of N conductivity is provided on the upper surface of the substrate, the layer having an upper surface and a lower surface. A doped region of N conductivity is formed at an upper portion of the layer. A cathode contacts the doped region. A passivation layer is provided on the upper surface of the layer and proximate to the cathode.
    Type: Grant
    Filed: May 11, 2006
    Date of Patent: May 6, 2014
    Assignee: IXYS Corporation
    Inventor: Subhas Chandra Bose Jayappa Veeramma
  • Patent number: 8153481
    Abstract: A semiconductor power device comprises a semiconductor substrate. The substrate includes an N-type silicon region and N+ silicon region. An oxide layer overlies the N? type silicon region, the oxide layer formed using a Plasma Enhanced Chemical Vapor deposition (PECVD) method. First and second electrodes are coupled to the N? type silicon region and the N+ type silicon region, respectively. The oxide layer has a thickness 0.5 to 3 microns. The power device also includes a polymide layer having a thickness of 3 to 20 microns; a first field plate overlying the oxide layer; and second field plate overlying the polymide layer and the first field plate, wherein the second field plate overlaps the first field plate by 2 to 15 microns.
    Type: Grant
    Filed: April 27, 2006
    Date of Patent: April 10, 2012
    Assignee: IXYS Corporation
    Inventor: Subhas Chandra Bose Jayappa Veeramma