Patents by Inventor Srikanth Krishnan

Srikanth Krishnan 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: 20260150332
    Abstract: Semiconductor devices and fabrication methods thereof are described. For example, a semiconductor device includes a source region and a drain region having a first conductivity type disposed in a semiconductor layer having an opposite second conductivity type, a shallow trench isolation structure disposed in the semiconductor layer between the source region and the drain region, a gate dielectric layer disposed over the semiconductor layer and extending between the source region and the shallow trench isolation structure, a gate electrode disposed over the gate dielectric layer and extending toward the drain region and over the shallow trench isolation structure, and a field plate spacer between the gate electrode and the shallow trench isolation structure.
    Type: Application
    Filed: November 27, 2024
    Publication date: May 28, 2026
    Inventors: Pinghai Hao, Bikram Kishore Mahajan, Dhanoop Varghese, Srikanth Krishnan
  • Patent number: 12598799
    Abstract: An integrated circuit, including a source region, a drain region, a channel region between the source region and the drain region, and a gate for inducing a conductive path through the channel region. The integrated circuit also includes structure, proximate a curved length of the gate, for inhibiting current flow along a portion of the channel region.
    Type: Grant
    Filed: August 31, 2021
    Date of Patent: April 7, 2026
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Jungwoo Joh, Sunglyong Kim, Seetharaman Sridhar, Sameer Pendharkar, James Craig Ondrusek, Srikanth Krishnan
  • Publication number: 20260063706
    Abstract: One example includes a method for performing a BTI test process of DUTs. The method includes coupling contact pads of a DUT circuit to testing equipment. The DUT circuit includes a differential input stage and a gain stage. The differential input stage include a differential pair of transistors that are fabrication matched to the DUTs. The method also includes providing a BTI stress from the testing equipment to one of the differential pair of transistor devices to simulate BTI aging of the respective one of the differential pair of the transistors. The method also includes providing a differential input voltage from the testing equipment to the differential input stage. The method further includes measuring an output voltage at an output of the gain stage via the testing equipment in response to the differential input voltage to determine a threshold voltage change between the differential pair of transistor devices.
    Type: Application
    Filed: August 30, 2024
    Publication date: March 5, 2026
    Inventors: VIJAY KUMAR REDDY, ARIF SONNET, DHANOOP VARGHESE, SRIKANTH KRISHNAN, VIJAYA VEMURI
  • Publication number: 20230061337
    Abstract: An integrated circuit, including a source region, a drain region, a channel region between the source region and the drain region, and a gate for inducing a conductive path through the channel region. The integrated circuit also includes structure, proximate a curved length of the gate, for inhibiting current flow along a portion of the channel region.
    Type: Application
    Filed: August 31, 2021
    Publication date: March 2, 2023
    Inventors: Jungwoo Joh, Sunglyong Kim, Seetharaman Sridhar, Sameer Pendharkar, James Craig Ondrusek, Srikanth Krishnan
  • Patent number: 9476933
    Abstract: A method includes coupling a gate pulse generator to a gate terminal of a power transistor device under test, coupling a drain pulse generator to a drain terminal of the power transistor device under test; for a first set of test conditions, activating the drain pulse generator for each of the test conditions to apply a voltage pulse to the drain terminal, and for each of the test conditions, applying a voltage pulse to the gate terminal, the gate pulse rising only after the drain pulse falls below a predetermined threshold; for a second set of test conditions, applying a voltage pulse to the drain terminal, and applying a voltage pulse to the gate terminal, the drain pulse generator and the gate pulse generator both being active so that there is some overlap; and measuring the drain current into the power transistor device under test. An apparatus is disclosed.
    Type: Grant
    Filed: November 19, 2014
    Date of Patent: October 25, 2016
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Jungwoo Joh, Srikanth Krishnan, Sameer Pendharkar
  • Publication number: 20150160285
    Abstract: A method includes coupling a gate pulse generator to a gate terminal of a power transistor device under test, coupling a drain pulse generator to a drain terminal of the power transistor device under test; for a first set of test conditions, activating the drain pulse generator for each of the test conditions to apply a voltage pulse to the drain terminal, and for each of the test conditions, applying a voltage pulse to the gate terminal, the gate pulse rising only after the drain pulse falls below a predetermined threshold; for a second set of test conditions, applying a voltage pulse to the drain terminal, and applying a voltage pulse to the gate terminal, the drain pulse generator and the gate pulse generator both being active so that there is some overlap; and measuring the drain current into the power transistor device under test. An apparatus is disclosed.
    Type: Application
    Filed: November 19, 2014
    Publication date: June 11, 2015
    Inventors: Jungwoo Joh, Srikanth Krishnan, Sameer Pendharkar
  • Patent number: 8219953
    Abstract: Apportioning unequally contributions of different metal paths of a circuit to electromigration (EM) reliability. In an embodiment, a corresponding parameter value representing a magnitude of excess current flowing in a single direction in each metal path is determined. A desired reliability measure for electromigration (EM) is apportioned among the metal paths based on computed parameter values for the corresponding metal path. A reliability analysis for the circuit is performed based on the apportioning. In an embodiment, metal paths which predominantly carry currents with an average value less than a threshold are excluded from being considered as contributors to EM degradation.
    Type: Grant
    Filed: January 18, 2009
    Date of Patent: July 10, 2012
    Assignee: Texas Instruments Incorporated
    Inventors: Palkesh Jain, Young-Joon Park, Srikanth Krishnan, Guru Chakrapani Prasad
  • Patent number: 8138829
    Abstract: Various apparatuses and methods for varying segment activation in a segmented power amplifier are disclosed herein. For example, some embodiments provide a power amplifier including an input, an output, a plurality of amplifier segments and a controller. The amplifier segments are connected in parallel between the input and the output and are adapted to be activated and inactivated. The power level at the output may be controlled by changing a number of the amplifier segments that are activated concurrently. The controller is connected to the amplifier segments and is adapted to vary which of the amplifier segments are activated to arrive at a selected number of activated amplifier segments.
    Type: Grant
    Filed: May 27, 2010
    Date of Patent: March 20, 2012
    Assignee: Texas Instruments Incorporated
    Inventors: Vijay Kumar Reddy, Srikanth Krishnan, Brian P Ginsburg, Srinath Mathur Ramaswamy, Chih-Ming Hung
  • Publication number: 20110291754
    Abstract: Various apparatuses and methods for varying segment activation in a segmented power amplifier are disclosed herein. For example, some embodiments provide a power amplifier including an input, an output, a plurality of amplifier segments and a controller. The amplifier segments are connected in parallel between the input and the output and are adapted to be activated and inactivated. The power level at the output may be controlled by changing a number of the amplifier segments that are activated concurrently. The controller is connected to the amplifier segments and is adapted to vary which of the amplifier segments are activated to arrive at a selected number of activated amplifier segments.
    Type: Application
    Filed: May 27, 2010
    Publication date: December 1, 2011
    Inventors: Vijay Kumar Reddy, Srikanth Krishnan, Brian P. Ginsburg, Srinath Mathur Ramaswamy, Chih-Ming Hung
  • Patent number: 7974595
    Abstract: One embodiment relates to an on-chip power amplifier (PA) test circuit. In one embodiment, a PA test circuit comprises a controllable oscillator (CO) configured to generate a radio frequency (RF) signal, a parallel resonant circuit tuned to the radio frequency, a pre-power amplifier (PPA) coupled to the CO and the parallel resonant circuit, the PPA configured to amplify and drive the RF signal from an output of the PPA into a load. The test circuit may further comprise a first transmission gate configured to couple the RF signal from the CO to an input of the PPA. One testing methodology for a PA test circuit comprises stressing the PPA with an RF signal, measuring a characteristic of the PPA, determining stress degradation from the characteristic measurements, and repeating the stressing and characteristic measurements until a maximum stress degradation is achieved or a maximum stress has been applied.
    Type: Grant
    Filed: January 11, 2008
    Date of Patent: July 5, 2011
    Assignee: Texas Instruments Incorporated
    Inventors: Vijay Kumar Reddy, Andrew Marshall, Siraj Akhtar, Srikanth Krishnan, Karan Singh Bhatia
  • Patent number: 7808266
    Abstract: Apparatus and methods are disclosed for evaluating degradation of a transistor in a cross coupled pair of an RF oscillator independently. A MOS device can be coupled between a separated center-tap inductor. By appropriately sizing the MOS device and turning the MOS device on during operation of RF oscillator, a good contact can again be made that allows the oscillator to operate at design performance. By turning the MOS device off, the supplies can be separates such that I-V characteristics of both transistors of the cross-coupled pair may be obtained.
    Type: Grant
    Filed: January 13, 2009
    Date of Patent: October 5, 2010
    Assignee: Texas Instruments Incorporated
    Inventors: Andrew Marsall, Srikanth Krishnan
  • Patent number: 7750400
    Abstract: An integrated circuit (IC) includes at least a first complementary MOS (CMOS) circuit, the first CMOS circuit comprising one or more first n-channel MOS (NMOS) transistors and one or more first p-channel MOS (PMOS) transistors, where the first NMOS transistors and the first PMOS transistors are arranged in the first CMOS circuit to drive at least a first common node of the first CMOS circuit. An average of the effective gate channel lengths of the first NMOS transistors (first NMOS average length) is at least 2% greater than an average of the effective gate channel lengths of the first PMOS transistors (first PMOS average length).
    Type: Grant
    Filed: August 15, 2008
    Date of Patent: July 6, 2010
    Assignee: Texas Instruments Incorporated
    Inventors: Ajit Shanware, Srikanth Krishnan
  • Publication number: 20100164533
    Abstract: Apparatus and methods are disclosed for evaluating degradation of a transistor in a cross coupled pair of an RF oscillator independently. A MOS device can be coupled between a separated center-tap inductor. By appropriately sizing the MOS device and turning the MOS device on during operation of RF oscillator, a good contact can again be made that allows the oscillator to operate at design performance. By turning the MOS device off, the supplies can be separates such that I-V characteristics of both transistors of the cross-coupled pair may be obtained.
    Type: Application
    Filed: January 13, 2009
    Publication date: July 1, 2010
    Applicant: Texas Instruments Incorporated
    Inventors: Andrew Marshall, Srikanth Krishnan
  • Publication number: 20100038683
    Abstract: An integrated circuit (IC) includes at least a first complementary MOS (CMOS) circuit, the first CMOS circuit comprising one or more first n-channel MOS (NMOS) transistors and one or more first p-channel MOS (PMOS) transistors, where the first NMOS transistors and the first PMOS transistors are arranged in the first CMOS circuit to drive at least a first common node of the first CMOS circuit. An average of the effective gate channel lengths of the first NMOS transistors (first NMOS average length) is at least 2% greater than an average of the effective gate channel lengths of the first PMOS transistors (first PMOS average length).
    Type: Application
    Filed: August 15, 2008
    Publication date: February 18, 2010
    Inventors: Ajit Shanware, Srikanth Krishnan
  • Patent number: 7638412
    Abstract: According to one embodiment of the invention, a silicon-on-insulator device includes an insulative layer formed overlying a substrate and a source and drain region formed overlying the insulative layer. The source region and the drain region comprise a material having a first conductivity type. A body region is disposed between the source region and the drain region and overlying the insulative layer. The body region comprises a material having a second conductivity type. A gate insulative layer overlies the body region. This device also includes a gate region overlying the gate insulative layer. The device also includes a diode circuit conductively coupled to the source region and a conductive connection coupling the gate region to the diode circuit.
    Type: Grant
    Filed: July 24, 2007
    Date of Patent: December 29, 2009
    Assignee: Texas Instruments Incorporated
    Inventors: James D. Gallia, Srikanth Krishnan, Anand T. Krishnan
  • Publication number: 20090187869
    Abstract: Apportioning unequally contributions of different metal paths of a circuit to electromigration (EM) reliability. In an embodiment, a corresponding parameter value representing a magnitude of excess current flowing in a single direction in each metal path is determined. A desired reliability measure for electromigration (EM) is apportioned among the metal paths based on computed parameter values for the corresponding metal path. A reliability analysis for the circuit is performed based on the apportioning. In an embodiment, metal paths which predominantly carry currents with an average value less than a threshold are excluded from being considered as contributors to EM degradation.
    Type: Application
    Filed: January 18, 2009
    Publication date: July 23, 2009
    Applicant: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Palkesh Jain, Young-Joon Park, Srikanth Krishnan, Guruprasad C
  • Publication number: 20090167429
    Abstract: One embodiment relates to an on-chip power amplifier (PA) test circuit. In one embodiment, a PA test circuit comprises a controllable oscillator (CO) configured to generate a radio frequency (RF) signal, a parallel resonant circuit tuned to the radio frequency, a pre-power amplifier (PPA) coupled to the CO and the parallel resonant circuit, the PPA configured to amplify and drive the RF signal from an output of the PPA into a load. The test circuit may further comprise a first transmission gate configured to couple the RF signal from the CO to an input of the PPA. One testing methodology for a PA test circuit comprises stressing the PPA with an RF signal, measuring a characteristic of the PPA, determining stress degradation from the characteristic measurements, and repeating the stressing and characteristic measurements until a maximum stress degradation is achieved or a maximum stress has been applied.
    Type: Application
    Filed: January 11, 2008
    Publication date: July 2, 2009
    Applicant: Texas Instruments Incorporated
    Inventors: Vijay Kumar Reddy, Andrew Marshall, Siraj Akhtar, Srikanth Krishnan, Karan Singh Bhatia
  • Publication number: 20070264804
    Abstract: According to one embodiment of the invention, a silicon-on-insulator device includes an insulative layer formed overlying a substrate and a source and drain region formed overlying the insulative layer. The source region and the drain region comprise a material having a first conductivity type. A body region is disposed between the source region and the drain region and overlying the insulative layer. The body region comprises a material having a second conductivity type. A gate insulative layer overlies the body region. This device also includes a gate region overlying the gate insulative layer. The device also includes a diode circuit conductively coupled to the source region and a conductive connection coupling the gate region to the diode circuit.
    Type: Application
    Filed: July 24, 2007
    Publication date: November 15, 2007
    Applicant: TEXAS INSTRUMENTS INCORPORATED
    Inventors: James Gallia, Srikanth Krishnan, Anand Krishnan
  • Patent number: 7262468
    Abstract: According to one embodiment of the invention, a silicon-on-insulator device includes an insulative layer formed overlying a substrate and a source and drain region formed overlying the insulative layer. The source region and the drain region comprise a material having a first conductivity type. A body region is disposed between the source region and the drain region and overlying the insulative layer. The body region comprises a material having a second conductivity type. A gate insulative layer overlies the body region. This device also includes a gate region overlying the gate insulative layer. The device also includes a diode circuit conductively coupled to the source region and a conductive connection coupling the gate region to the diode circuit.
    Type: Grant
    Filed: December 28, 2001
    Date of Patent: August 28, 2007
    Assignee: Texas Instruments Incorporated
    Inventors: James D. Gallia, Srikanth Krishnan, Anand T. Krishnan
  • Patent number: 7218132
    Abstract: Methods and systems are provided for characterizing the negative temperature bias instability of a transistor. A bias voltage is maintained at a drain terminal of the transistor during a test period. A stress voltage is maintained at a gate terminal of the transistor during the test period, such that the stress voltage is applied concurrently with the bias voltage. At least one characteristic of the transistor is measured at periodic intervals during the stress period to determine a degradation of the at least one characteristic caused by the stress voltage until a termination event occurs.
    Type: Grant
    Filed: November 30, 2005
    Date of Patent: May 15, 2007
    Assignee: Texas Instruments Incorporated
    Inventors: Anand T. Krishnan, Srikanth Krishnan, Vijay Reddy, Cathy Chancellor