Patents by Inventor Shekar Mallikarjunaswamy

Shekar Mallikarjunaswamy 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).

  • Publication number: 20240063777
    Abstract: A power device, circuit and method of making are described. The power device circuit includes a semiconductor substrate composition having a substrate layer of a first conductivity type wherein the first conductivity type is opposite a second conductivity type. Two or more lateral double diffused metal oxide semiconductor (LDMOS) devices are formed in the substrate layer and integrated into an isolation region of a high voltage well, wherein each LDMOS is isolated from a power device substrate area by an isolator structure formed from the substrate layer. One or more boost structures are integrated into the isolation region of the high voltage well wherein the one or more boost structures are in contact with the high voltage well and extend into the isolation region of the high voltage well.
    Type: Application
    Filed: August 19, 2022
    Publication date: February 22, 2024
    Inventors: Shekar Mallikarjunaswamy, Jongjib Kim, Son Tran
  • Publication number: 20230260986
    Abstract: A transient voltage suppressor (TVS) device includes a MOS-triggered silicon controlled rectifier (SCR) as the high-side steering diode and a silicon controlled rectifier (SCR) for the low-side steering diode. In one embodiment, the MOS-triggered SCR includes alternating p-type and n-type regions and a diode-connected MOS transistor integrated therein to trigger the silicon controlled rectifier to turn on. In one embodiment, the SCR of the low-side steering diode includes alternating p-type and n-type regions where the p-type region adjacent the n-type region forming the cathode terminal is not biased to any electrical potential.
    Type: Application
    Filed: April 22, 2023
    Publication date: August 17, 2023
    Inventor: Shekar Mallikarjunaswamy
  • Patent number: 11664368
    Abstract: A transient voltage suppressor (TVS) device uses a punch-through silicon controlled rectifier (SCR) structure for the low-side steering diode where the punch-through SCR structure realizes low capacitance at the protected node. In some embodiments, the punch-through silicon controlled rectifier of the low-side steering diode includes a first doped region formed in a first epitaxial layer, a first well formed spaced apart from the first doped region where the first well is not biased to any electrical potential, and a second doped region formed in the first well. The first doped region, the first epitaxial layer, the first well and the second doped region form the punch-through silicon controlled rectifier, with the first doped region forming the anode and the second doped region forming the cathode of the punch-through silicon controlled rectifier.
    Type: Grant
    Filed: September 25, 2020
    Date of Patent: May 30, 2023
    Assignee: Alpha & Omega Semiconductor (Cayman) Ltd.
    Inventor: Shekar Mallikarjunaswamy
  • Publication number: 20230050292
    Abstract: A bidirectional transient voltage suppressor (TVS) protection circuit includes two sets of steering diodes, a clamp circuit including an MOS transistor integrated with a silicon controlled rectifier (SCR) and a trigger circuit. In response to a voltage applied to one of the protected nodes exceeding a first voltage level, the trigger circuit drives the MOS transistor to cause a current flow at the SCR to trigger an SCR action and the SCR clamps the voltage at the respective protected node at a clamping voltage. In other embodiments, a bidirectional transient voltage suppressor (TVS) protection circuit includes two sets of steering diodes with a clamp device merged with a steering diode in each set. In some embodiments, the TVS protection circuit realizes low capacitance at the protected nodes by fully or almost completely depleting the P-N junction connected to the protected nodes in the operating voltage range.
    Type: Application
    Filed: September 14, 2022
    Publication date: February 16, 2023
    Inventors: Shekar Mallikarjunaswamy, Ning Shi
  • Publication number: 20230005906
    Abstract: A transient voltage suppressing device includes a plurality of fingers arranged laterally along a major surface of an epitaxial layer. The plurality of fingers includes fingers of a first type and fingers of a second type. The first type and second type of fingers each include a silicon controlled rectifier (SCR) region and a junction diode region. The plurality of fingers of the second type are conductively coupled together by a second metal layer disposed over top a first metal layer and electrically insulated from the first metal layer. The first metal layer conductively couples the SCR region and junction diode region of the first type of finger.
    Type: Application
    Filed: June 30, 2021
    Publication date: January 5, 2023
    Inventors: Shekar Mallikarjunaswamy, Juan Luo
  • Patent number: 11462532
    Abstract: A bidirectional transient voltage suppressor (TVS) circuit for data pins of electronic devices includes two sets of steering diodes and a diode triggered clamp device in some embodiment. In other embodiments, a bidirectional transient voltage suppressor (TVS) circuit for data pins of electronic devices includes two sets of steering diodes with a clamp device merged with a steering diode in each set. The TVS circuit is constructed to realize low capacitance at the protected nodes and improved clamping voltage for robust protection against surge evens. In some embodiments, the TVS circuit realizes low capacitance at the protected nodes by fully or almost completely depleting the P-N junction connected to the protected nodes in the operating voltage range. In this manner, the TVS circuit does not present undesirable parasitic capacitance to the data pins being protected, especially when the data pins are applied in high speed applications.
    Type: Grant
    Filed: January 13, 2021
    Date of Patent: October 4, 2022
    Assignee: Alpha and Omega Semiconductor (Cayman) Ltd.
    Inventors: Shekar Mallikarjunaswamy, Ning Shi
  • Patent number: 11456596
    Abstract: A MOSFET and an electrostatic discharge (ESD) protection device on a common chip includes a MOSFET with a source, a gate, and a drain, and an ESD protection device configured to implement a diode function that is biased to prevent current from flowing through the common chip from the source to the drain.
    Type: Grant
    Filed: March 18, 2021
    Date of Patent: September 27, 2022
    Assignee: ALPHA AND OMEGA SEMICONDUCTOR INCORPORATED
    Inventor: Shekar Mallikarjunaswamy
  • Publication number: 20220208750
    Abstract: A transient voltage suppressor (TVS) device includes a silicon controlled rectifier (SCR) as the clamp device between a high-side steering diode and a low-side steering diode. The SCR includes alternating emitter and base regions arranged interleaving in a direction along a major surface of a semiconductor layer and orthogonal to a current path of the SCR. The TVS device realizes low capacitance and high holding voltage at the protected node.
    Type: Application
    Filed: December 29, 2020
    Publication date: June 30, 2022
    Inventor: Shekar Mallikarjunaswamy
  • Patent number: 11152351
    Abstract: A bidirectional transient voltage suppressor is constructed as an NPN bipolar transistor incorporating optimized collector-base junction realizing avalanche mode breakdown. In some embodiments, the bidirectional transient voltage suppressor is constructed as an NPN bipolar transistor incorporating individually optimized collector-base and emitter-base junctions with the optimized junctions being spatially distributed. The optimized collector-base and emitter-base junctions both realize avalanche mode breakdown to improve the breakdown voltage of the transistor. Alternately, a unidirectional transient voltage suppressor is constructed as an NPN bipolar transistor with a PN junction diode connected in parallel in the reverse bias direction to the protected node and incorporating individually optimized collector-base junction of the bipolar transistor and p-n junction of the diode.
    Type: Grant
    Filed: June 10, 2020
    Date of Patent: October 19, 2021
    Assignee: Alpha and Omega Semiconductor (Cayman) Ltd.
    Inventor: Shekar Mallikarjunaswamy
  • Publication number: 20210210954
    Abstract: A MOSFET and an electrostatic discharge (ESD) protection device on a common chip includes a MOSFET with a source, a gate, and a drain, and an ESD protection device configured to implement a diode function that is biased to prevent current from flowing through the common chip from the source to the drain.
    Type: Application
    Filed: March 18, 2021
    Publication date: July 8, 2021
    Inventor: Shekar Mallikarjunaswamy
  • Publication number: 20210159223
    Abstract: A bidirectional transient voltage suppressor (TVS) circuit for data pins of electronic devices includes two sets of steering diodes and a diode triggered clamp device in some embodiment. In other embodiments, a bidirectional transient voltage suppressor (TVS) circuit for data pins of electronic devices includes two sets of steering diodes with a clamp device merged with a steering diode in each set. The TVS circuit is constructed to realize low capacitance at the protected nodes and improved clamping voltage for robust protection against surge evens. In some embodiments, the TVS circuit realizes low capacitance at the protected nodes by fully or almost completely depleting the P-N junction connected to the protected nodes in the operating voltage range. In this manner, the TVS circuit does not present undesirable parasitic capacitance to the data pins being protected, especially when the data pins are applied in high speed applications.
    Type: Application
    Filed: January 13, 2021
    Publication date: May 27, 2021
    Inventors: Shekar Mallikarjunaswamy, Ning Shi
  • Patent number: 10978869
    Abstract: A MOSFET and an electrostatic discharge (ESD) protection device on a common chip includes a MOSFET with a source, a gate, and a drain, and an ESD protection device configured to implement a diode function that is biased to prevent current from flowing through the common chip from the source to the drain.
    Type: Grant
    Filed: August 23, 2016
    Date of Patent: April 13, 2021
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventor: Shekar Mallikarjunaswamy
  • Patent number: 10937780
    Abstract: A bidirectional transient voltage suppressor (TVS) circuit for data pins of electronic devices includes two sets of steering diodes and a diode triggered clamp device in some embodiment. In other embodiments, a bidirectional transient voltage suppressor (TVS) circuit for data pins of electronic devices includes two sets of steering diodes with a clamp device merged with a steering diode in each set. The TVS circuit is constructed to realize low capacitance at the protected nodes and improved clamping voltage for robust protection against surge evens. In some embodiments, the TVS circuit realizes low capacitance at the protected nodes by fully or almost completely depleting the P-N junction connected to the protected nodes in the operating voltage range. In this manner, the TVS circuit does not present undesirable parasitic capacitance to the data pins being protected, especially when the data pins are applied in high speed applications.
    Type: Grant
    Filed: June 20, 2019
    Date of Patent: March 2, 2021
    Assignee: Alpha and Omega Semiconductor (Cayman) Ltd.
    Inventors: Shekar Mallikarjunaswamy, Ning Shi
  • Publication number: 20210013192
    Abstract: A transient voltage suppressor (TVS) device uses a punch-through silicon controlled rectifier (SCR) structure for the low-side steering diode where the punch-through SCR structure realizes low capacitance at the protected node. In some embodiments, the punch-through silicon controlled rectifier of the low-side steering diode includes a first doped region formed in a first epitaxial layer, a first well formed spaced apart from the first doped region where the first well is not biased to any electrical potential, and a second doped region formed in the first well. The first doped region, the first epitaxial layer, the first well and the second doped region form the punch-through silicon controlled rectifier, with the first doped region forming the anode and the second doped region forming the cathode of the punch-through silicon controlled rectifier.
    Type: Application
    Filed: September 25, 2020
    Publication date: January 14, 2021
    Inventor: Shekar Mallikarjunaswamy
  • Patent number: 10825805
    Abstract: A transient voltage suppressor (TVS) device uses a punch-through silicon controlled rectifier (SCR) structure for the high-side steering diode and/or the low-side steering diode where the punch-through SCR structure realizes low capacitance at the protected node. In some embodiments, the breakdown voltage of the TVS device is tailored by connecting two or more forward biased diodes in series. The low capacitance TVS device can be configured for unidirectional or bidirectional applications. In some embodiments, the TVS device includes a MOS-triggered silicon controlled rectifier as the high-side steering diode. The breakdown voltage of the TVS device can be adjusted by adjusting the threshold voltage of the MOS transistor.
    Type: Grant
    Filed: October 26, 2018
    Date of Patent: November 3, 2020
    Assignee: Alpha & Omega Semiconductor (Cayman) Ltd.
    Inventor: Shekar Mallikarjunaswamy
  • Publication number: 20200303370
    Abstract: A bidirectional transient voltage suppressor is constructed as an NPN bipolar transistor incorporating optimized collector-base junction realizing avalanche mode breakdown. In some embodiments, the bidirectional transient voltage suppressor is constructed as an NPN bipolar transistor incorporating individually optimized collector-base and emitter-base junctions with the optimized junctions being spatially distributed. The optimized collector-base and emitter-base junctions both realize avalanche mode breakdown to improve the breakdown voltage of the transistor. Alternately, a unidirectional transient voltage suppressor is constructed as an NPN bipolar transistor with a PN junction diode connected in parallel in the reverse bias direction to the protected node and incorporating individually optimized collector-base junction of the bipolar transistor and p-n junction of the diode.
    Type: Application
    Filed: June 10, 2020
    Publication date: September 24, 2020
    Inventor: Shekar Mallikarjunaswamy
  • Patent number: 10720422
    Abstract: A bidirectional transient voltage suppressor is constructed as an NPN bipolar transistor incorporating optimized collector-base junction realizing avalanche mode breakdown. In some embodiments, the bidirectional transient voltage suppressor is constructed as an NPN bipolar transistor incorporating individually optimized collector-base and emitter-base junctions with the optimized junctions being spatially distributed. The optimized collector-base and emitter-base junctions both realize avalanche mode breakdown to improve the breakdown voltage of the transistor. Alternately, a unidirectional transient voltage suppressor is constructed as an NPN bipolar transistor with a PN junction diode connected in parallel in the reverse bias direction to the protected node and incorporating individually optimized collector-base junction of the bipolar transistor and p-n junction of the diode.
    Type: Grant
    Filed: January 4, 2019
    Date of Patent: July 21, 2020
    Assignee: ALPHA AND OMEGA SEMICONDUCTOR (CAYMAN) LTD.
    Inventor: Shekar Mallikarjunaswamy
  • Patent number: 10692851
    Abstract: A transient voltage suppressor (TVS) is constructed as an NPN bipolar transistor including individually optimized collector-base and emitter-base junctions both with avalanche mode breakdown. The TVS device is constructed using a base that includes a lightly doped base region bordered by a pair of more heavily doped base regions. The two more heavily doped base regions are used to form the collector-base junction and the emitter-base junction both as avalanche breakdown junctions. The lightly doped base region between the collector-base and emitter-base doping regions ensures low leakage current in the TVS device. In this manner, the TVS bipolar transistor of the present invention provides high surge protection with robust clamping while ensuring low leakage current.
    Type: Grant
    Filed: November 1, 2018
    Date of Patent: June 23, 2020
    Assignee: ALPHA AND OMEGA SEMICONDUCTOR (CAYMAN) LTD.
    Inventors: Shekar Mallikarjunaswamy, Ning Shi
  • Publication number: 20200135714
    Abstract: A transient voltage suppressor (TVS) device uses a punch-through silicon controlled rectifier (SCR) structure for the high-side steering diode and/or the low-side steering diode where the punch-through SCR structure realizes low capacitance at the protected node. In some embodiments, the breakdown voltage of the TVS device is tailored by connecting two or more forward biased diodes in series. The low capacitance TVS device can be configured for unidirectional or bidirectional applications. In some embodiments, the TVS device includes a MOS-triggered silicon controlled rectifier as the high-side steering diode. The breakdown voltage of the TVS device can be adjusted by adjusting the threshold voltage of the MOS transistor.
    Type: Application
    Filed: October 26, 2018
    Publication date: April 30, 2020
    Inventor: Shekar Mallikarjunaswamy
  • Patent number: 10497697
    Abstract: A transient voltage suppressor (TVS) circuit includes a first finger and a second finger of semiconductor regions arranged laterally along a first direction on a major surface of a semiconductor layer, the first finger and second finger extending in a second direction orthogonal to the first direction on the major surface of the semiconductor layer. The semiconductor regions in a first portion of the first and second fingers form a silicon controlled rectifier and the semiconductor regions in a second portion of the first and second fingers form a P-N junction diode.
    Type: Grant
    Filed: October 16, 2018
    Date of Patent: December 3, 2019
    Assignee: Alpha and Omega Semiconductor (Cayman) Ltd.
    Inventor: Shekar Mallikarjunaswamy