Patents by Inventor Karthik Kadirvel

Karthik Kadirvel 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: 9091736
    Abstract: Systems and methods for cell anomaly detection are provided. The disclosed systems and methods of cell anomaly detection may use a single circuit to detect both cell-open and imbalance conditions. Disclosed embodiments may incorporate a continuous or a sampled time system (i.e. cell anomaly detection is performed when an enable signal is active). An example embodiment includes receiving voltages of a plurality of cells of a battery pack; converting the received voltages to currents; determining a maximum current of the currents; determining whether at least one of the currents is anomalous; and reporting the at least one anomalous current as indicative of a bad cell.
    Type: Grant
    Filed: January 6, 2009
    Date of Patent: July 28, 2015
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Karthik Kadirvel, Umar Jameer Lyles, John H. Carpenter, Jr.
  • Patent number: 8810311
    Abstract: An amplifier having an inverting input and a non-inverting input; a capacitor coupled to inverting input of the amplifier; an input voltage conveyance control circuit, having a first switch and a second switch, the first switch coupled to the capacitor, and the second switch coupled to the non-inverting input of the amplifier; a reference voltage conveyance control circuit having a third switch and a fourth switch, a shared node coupled between third switch and fourth switch, the fourth switch coupled to the non-inverting input of the amplifier; a fifth switch coupled to an output of the amplifier; a leakage control circuit having a sixth switch and seventh switch, the sixth switch coupled between the inverting amplifier input and the fifth switch, the seventh switch coupled to the sixth switch and the capacitor; and a first resistor coupled from the output of the amplifier to the first switch.
    Type: Grant
    Filed: July 25, 2012
    Date of Patent: August 19, 2014
    Assignee: Texas Instruments Incorporated
    Inventors: Vadim Valerievich Ivanov, Brian Phillip Lum-Shue-Chan, Karthik Kadirvel
  • Publication number: 20140029147
    Abstract: Embodiments of the systems and methods of direct cell attachment for battery cells disclosed herein operate without the protection FETs and the protection IC, thereby enabling the direct attachment of battery cells to the system without compromising safety. A charger IC comprises a switching regulator whose output is used to charge the battery through a pass device. In example embodiments of the disclosed systems and methods of direct cell attachment, a combination of switching FETs and the pass device are used as a protection device instead of the charge and discharge FETs. During normal operation, the pass device may be used to charge the battery using the traditional battery charging profile. Under fault condition, the switching FETs and pass device may be driven appropriately to protect the system.
    Type: Application
    Filed: May 20, 2013
    Publication date: January 30, 2014
    Applicant: Texas Instruments Incorporated
    Inventors: Karthik Kadirvel, III, Steve Harrell, Brian Lum-Shue-Chan
  • Publication number: 20130241637
    Abstract: An amplifier having an inverting input and a non-inverting input; a capacitor coupled to inverting input of the amplifier; an input voltage conveyance control circuit, having a first switch and a second switch, the first switch coupled to the capacitor, and the second switch coupled to the non-inverting input of the amplifier; a reference voltage conveyance control circuit having a third switch and a fourth switch, a shared node coupled between third switch and fourth switch, the fourth switch coupled to the non-inverting input of the amplifier; a fifth switch coupled to an output of the amplifier; a leakage control circuit having a sixth switch and seventh switch, the sixth switch coupled between the inverting amplifier input and the fifth switch, the seventh switch coupled to the sixth switch and the capacitor; and a first resistor coupled from the output of the amplifier to the first switch.
    Type: Application
    Filed: July 25, 2012
    Publication date: September 19, 2013
    Applicant: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Vadim Valerievich Ivanov, Brian Phillip Lum-Shue-Chan, Karthik Kadirvel
  • Patent number: 8305039
    Abstract: Systems and methods for determining a state of charge (SOC) of an electrical energy storage device are disclosed. In one embodiment, a system is provided for determining the SOC of an electrical energy storage device comprises at least one memristor coupled in series with the electrical energy storage device to monitor charge current and discharge current of the electrical energy storage device. The system also includes a readout controller configured to determine the SOC of the electrical energy storage device based on the resistance of the memristor.
    Type: Grant
    Filed: July 15, 2010
    Date of Patent: November 6, 2012
    Assignee: Texas Instruments Incorporated
    Inventors: Karthik Kadirvel, John H. Carpenter, Jr.
  • Patent number: 8264200
    Abstract: Various apparatuses and methods for detecting cell connection status of a multi-cell battery are disclosed herein. For example, some embodiments provide an apparatus for detecting cell connection status of a multi-cell battery. The apparatus includes a battery cell input for each cell, a cell connection status detector for each cell, and at least one comparator. Each of the cell connection status detectors is connected to a battery cell input and has a current-based status indicator output. The at least one comparator is connected to the current-based status indicator outputs. Each of the plurality of cell connection status detectors floats in a different supply voltage range. The at least one comparator is referenced to a lower voltage potential than at least one of the plurality of cell connection status detectors.
    Type: Grant
    Filed: May 15, 2009
    Date of Patent: September 11, 2012
    Assignee: Texas Instruments Incorporated
    Inventors: Brian Lum-Shue-Chan, Karthik Kadirvel, John H. Carpenter, Jr., Umar Jameer Lyles
  • Patent number: 8253435
    Abstract: Methods and apparatus to detect voltage conditions of power supplies are disclosed. An example power supply monitor to detect fault conditions in a power supply includes a capacitive element communicatively coupled to the power supply, the capacitive element being configured to change state between a collapsed state and an open state in response to the power supply having a first voltage associated with a first fault condition of the power supply; a detector communicatively coupled to the capacitive element to detect a voltage spike generated from the state change of the capacitive element; and a signal generator to generate a fault signal in response to the voltage spike to indicate the power supply being in the first fault condition.
    Type: Grant
    Filed: September 13, 2010
    Date of Patent: August 28, 2012
    Assignee: Texas Instruments Incorporated
    Inventors: Karthik Kadirvel, John H. Carpenter, Jr.
  • Publication number: 20120062272
    Abstract: Methods and apparatus to detect voltage conditions of power supplies are disclosed. An example power supply monitor to detect fault conditions in a power supply includes a capacitive element communicatively coupled to the power supply, the capacitive element being configured to change state between a collapsed state and an open state in response to the power supply having a first voltage associated with a first fault condition of the power supply; a detector communicatively coupled to the capacitive element to detect a voltage spike generated from the state change of the capacitive element; and a signal generator to generate a fault signal in response to the voltage spike to indicate the power supply being in the first fault condition.
    Type: Application
    Filed: September 13, 2010
    Publication date: March 15, 2012
    Inventors: Karthik Kadirvel, John H. Carpenter, JR.
  • Publication number: 20120013306
    Abstract: Systems and methods for determining a state of charge (SOC) of an electrical energy storage device are disclosed. In one embodiment, a system is provided for determining the SOC of an electrical energy storage device comprises at least one memristor coupled in series with the electrical energy storage device to monitor charge current and discharge current of the electrical energy storage device. The system also includes a readout controller configured to determine the SOC of the electrical energy storage device based on the resistance of the memristor.
    Type: Application
    Filed: July 15, 2010
    Publication date: January 19, 2012
    Inventors: Karthik Kadirvel, John H. Carpenter, JR.
  • Publication number: 20120013380
    Abstract: A system is provided for generating a plurality of different voltage level clock signals. The system comprises an electrical energy storage pack having a plurality of series coupled electrical energy storage cells that provide a plurality of different output voltage level, a reference oscillator that provides a reference clock signal and a plurality of voltage clamps that receive the plurality of different output voltage levels and output the plurality of different voltage level clock signals at respective output nodes. The plurality of voltage clamps are configured to clamp each of a given output node to a respective high-side voltage level in response to pulling up of the given output node toward a respective high output voltage level and to clamp each of the given output node to a respective low-side voltage level in response to pulling down of the output node toward a low output voltage level.
    Type: Application
    Filed: July 15, 2010
    Publication date: January 19, 2012
    Inventors: Karthik Kadirvel, Umar Jameer Lyles, John H. Carpenter, JR.
  • Patent number: 7999558
    Abstract: Systems and methods for overvoltage and undervoltage detection may be implemented with a fully differential circuit that includes a coarse comparator and a band gap based fine comparator. The coarse comparator may determine if the battery is closer to an OV condition or an UV condition. Based on the output of the coarse comparator, the trip point of the fine comparator is adjusted. The outputs of both comparators are pull-up circuits whose output is decoded to determine if an OV or a UV condition has occurred. The systems and methods accomplish valid circuit outputs even when the voltage across the battery reduces to zero volts. This may be achieved by using an active low signal for the UV condition and an active high signal for the OV condition. Thus, when the battery voltage goes to zero, the circuit evaluates to the correct output.
    Type: Grant
    Filed: March 6, 2009
    Date of Patent: August 16, 2011
    Assignee: Texas Instruments Incorporated
    Inventors: Umar Jameer Lyles, Karthik Kadirvel, John H. Carpenter, Jr.
  • Publication number: 20110012605
    Abstract: With batteries or cells, particularly lithium ion cells, it is important to determine when one or more cells have entered a fault condition (i.e., overvoltage or undervoltage). Conventional circuits employ measuring circuits that use multiple bandgap circuits and high voltage components. These conventional circuits, however, consume a great deal of area because of the use of these multiple bandgap circuits and the high voltage components. Here, a circuit is provided that reduces the number of bandgap circuits and reduces the number of high voltage components, reducing the area consumed and reducing the overall cost of production compared to conventional circuits.
    Type: Application
    Filed: December 21, 2009
    Publication date: January 20, 2011
    Applicant: Texas Instruments Incorporated
    Inventors: Umar J. Lyles, Karthik Kadirvel, John H. Carpenter, JR.
  • Publication number: 20100289497
    Abstract: Various apparatuses and methods for detecting cell connection status of a multi-cell battery are disclosed herein. For example, some embodiments provide an apparatus for detecting cell connection status of a multi-cell battery. The apparatus includes a battery cell input for each cell, a cell connection status detector for each cell, and at least one comparator. Each of the cell connection status detectors is connected to a battery cell input and has a current-based status indicator output. The at least one comparator is connected to the current-based status indicator outputs. Each of the plurality of cell connection status detectors floats in a different supply voltage range. The at least one comparator is referenced to a lower voltage potential than at least one of the plurality of cell connection status detectors.
    Type: Application
    Filed: May 15, 2009
    Publication date: November 18, 2010
    Inventors: Brian Lum-Shue-Chan, Karthik Kadirvel, John H. Carpenter, JR., Umar Jameer Lyles
  • Publication number: 20100225300
    Abstract: Systems and methods for overvoltage and undervoltage detection are provided. The disclosed systems and methods of overvoltage and undervoltage detection may be implemented with a fully differential circuit that includes a coarse comparator and a band gap based fine comparator. The coarse comparator may determine if the battery is closer to an OV condition or an UV condition. Based on the output of the coarse comparator, the trip point of the fine comparator is adjusted. The outputs of both comparators are pull-up circuits whose output is decoded to determine if an OV or a UV condition has occurred. The disclosed systems and methods of overvoltage and undervoltage detection accomplish valid circuit outputs even when the voltage across the battery reduces to zero volts. This may be achieved by using an active low signal for the UV condition and an active high signal for the OV condition. Thus, when the battery voltage goes to zero, the circuit evaluates to the correct output.
    Type: Application
    Filed: March 6, 2009
    Publication date: September 9, 2010
    Applicant: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Umar Jameer Lyles, Karthik Kadirvel, John H. Carpenter, JR.
  • Publication number: 20100173183
    Abstract: Systems and methods for cell anomaly detection are provided. The disclosed systems and methods of cell anomaly detection may use a single circuit to detect both cell-open and imbalance conditions. Disclosed embodiments may incorporate a continuous or a sampled time system (i.e. cell anomaly detection is performed when an enable signal is active). An example embodiment includes receiving voltages of a plurality of cells of a battery pack; converting the received voltages to currents; determining a maximum current of the currents; determining whether at least one of the currents is anomalous; and reporting the at least one anomalous current as indicative of a bad cell.
    Type: Application
    Filed: January 6, 2009
    Publication date: July 8, 2010
    Applicant: Texas Instruments Incorporated
    Inventors: Karthik Kadirvel, Umar Jameer Lyles, John H. Carpenter, JR.