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).
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Patent number: 10304970Abstract: 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: GrantFiled: January 20, 2018Date of Patent: May 28, 2019Assignee: IXYS, LLCInventor: Subhas Chandra Bose Jayappa Veeramma
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Publication number: 20180145186Abstract: 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: ApplicationFiled: January 20, 2018Publication date: May 24, 2018Inventor: Subhas Chandra Bose Jayappa Veeramma
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Patent number: 9935206Abstract: 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: GrantFiled: May 10, 2013Date of Patent: April 3, 2018Assignee: IXYS CorporationInventor: Subhas Chandra Bose Jayappa Veeramma
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Patent number: 9379203Abstract: 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: GrantFiled: June 6, 2015Date of Patent: June 28, 2016Assignee: IXYS CorporationInventor: Subhas Chandra Bose Jayappa Veeramma
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Publication number: 20150270370Abstract: 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: ApplicationFiled: June 6, 2015Publication date: September 24, 2015Inventor: Subhas Chandra Bose Jayappa Veeramma
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Patent number: 9087809Abstract: 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: GrantFiled: August 5, 2014Date of Patent: July 21, 2015Assignee: IXYS CorporationInventor: Subhas Chandra Bose Jayappa Veeramma
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Publication number: 20140346559Abstract: 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: ApplicationFiled: August 5, 2014Publication date: November 27, 2014Inventor: Subhas Chandra Bose Jayappa Veeramma
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Publication number: 20140332841Abstract: 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: ApplicationFiled: May 10, 2013Publication date: November 13, 2014Applicant: IXYS CorporationInventor: Subhas Chandra Bose Jayappa Veeramma
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Publication number: 20140332842Abstract: 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: ApplicationFiled: May 10, 2013Publication date: November 13, 2014Applicant: IXYS CorporationInventor: Subhas Chandra Bose Jayappa Veeramma
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Patent number: 8878236Abstract: 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: GrantFiled: May 10, 2013Date of Patent: November 4, 2014Assignee: IXYS CorporationInventor: Subhas Chandra Bose Jayappa Veeramma
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Patent number: 8836090Abstract: 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: GrantFiled: March 1, 2013Date of Patent: September 16, 2014Assignee: IXYS CorporationInventor: Subhas Chandra Bose Jayappa Veeramma
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Patent number: 8835975Abstract: 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: GrantFiled: May 10, 2013Date of Patent: September 16, 2014Assignee: IXYS CorporationInventor: Subhas Chandra Bose Jayappa Veeramma
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Publication number: 20140246761Abstract: 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: ApplicationFiled: March 1, 2013Publication date: September 4, 2014Applicant: IXYS CorporationInventor: Subhas Chandra Bose Jayappa Veeramma
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Patent number: 8716745Abstract: 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: GrantFiled: May 11, 2006Date of Patent: May 6, 2014Assignee: IXYS CorporationInventor: Subhas Chandra Bose Jayappa Veeramma
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Patent number: 8153481Abstract: 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: GrantFiled: April 27, 2006Date of Patent: April 10, 2012Assignee: IXYS CorporationInventor: Subhas Chandra Bose Jayappa Veeramma