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: 10724978
    Abstract: A portable communication device includes one or more sensors, a pair of electrodes associated with each sensor, and a processing circuit configured to apply a bias supply voltage to the pair of electrodes and to process output signals from the sensors. Each sensor is an ionic liquid sensor tuned for sensing a smell associated with a chemical species. The processing circuit further includes an artificial intelligence engine to enhance smell recognition capabilities of the device.
    Type: Grant
    Filed: September 28, 2018
    Date of Patent: July 28, 2020
    Assignee: Apple Inc.
    Inventors: Saroj K. Sahu, Karthik Kadirvel
  • Patent number: 10355497
    Abstract: In general, techniques are disclosed for providing short circuit protection to a battery pack having a number of battery cells, at least some of which are connected in parallel. Short circuit protection is provided by using pairs of electronic switches (e.g., integrated circuits consisting of a pair of transistors designed as battery charge/discharge switches) serially connected between one terminal of a battery cell and a battery pack's common node—a position which is upstream of conventional battery pack fault controllers. The state of all such switches may be controlled by a control unit that is also upstream of a conventional fault controller. The combination of switch pairs and control unit can provide a battery pack with over current (short circuit) protection without the use of thermal cutoff devises. The described devices and systems can also provide over voltage, under voltage and over temperature protection.
    Type: Grant
    Filed: May 13, 2016
    Date of Patent: July 16, 2019
    Assignee: Apple Inc.
    Inventors: Karthik Kadirvel, Soundararajan Manthiri
  • Publication number: 20190101501
    Abstract: A portable communication device includes one or more sensors, a pair of electrodes associated with each sensor, and a processing circuit configured to apply a bias supply voltage to the pair of electrodes and to process output signals from the sensors. Each sensor is an ionic liquid sensor tuned for sensing a smell associated with a chemical species. The processing circuit further includes an artificial intelligence engine to enhance smell recognition capabilities of the device.
    Type: Application
    Filed: September 28, 2018
    Publication date: April 4, 2019
    Inventors: Saroj K. SAHU, Karthik KADIRVEL
  • Patent number: 10236694
    Abstract: This disclosure describes a battery pack that includes a plurality of asymmetrical banks, with different capacities and/or voltages, and multiple taps, coupled to the corresponding banks, to power electrical loads. The battery pack also comprise a balancing circuit and a battery management unit. The battery pack may regulate voltages among the banks and/or balance the states of charge among the asymmetrical banks, by moving charges among the banks, by controlling one or more converters. The battery pack monitors the status of its banks and communicate with a host system via the battery management unit. Based on the monitored information and/or communication, the battery management unit generates control signals to drive the one or more converters.
    Type: Grant
    Filed: July 28, 2017
    Date of Patent: March 19, 2019
    Assignee: Apple Inc.
    Inventors: Thomas C. Greening, Karthik Kadirvel, Gary L. Stirk, Saroj K. Sahu, Kamran M. Hasan
  • Patent number: 10211653
    Abstract: Battery packs that include multiple battery cells that may be monitored using a reduced amount of circuitry and battery systems that may account for battery cell changes over aging and temperature.
    Type: Grant
    Filed: July 15, 2017
    Date of Patent: February 19, 2019
    Assignee: Apple Inc.
    Inventors: Karthik Kadirvel, Ankur Gupta, Hua Chen, Christopher C. Branson, David M. DeMuro, Alessandro Pelosi
  • Publication number: 20180337537
    Abstract: This disclosure relates generally to the field of providing highly accurate over current fault protection in charging systems and, more particularly, to systems in which the charge over current protection (COCP) and discharge over current protection (DOCP) circuitry in electronic devices are particularly resilient to variations in field-effect transistor (FET) resistance with temperature, gate drive, and/or process shift; variations in printed circuit board (PCB) resistance; and variations in integrated circuit (IC) trip voltages.
    Type: Application
    Filed: July 31, 2018
    Publication date: November 22, 2018
    Inventors: Karthik Kadirvel, Soundararajan Manthiri
  • Patent number: 10084326
    Abstract: This disclosure relates generally to the field of providing highly accurate over current fault protection in charging systems and, more particularly, to systems in which the charge over current protection (COCP) and discharge over current protection (DOCP) circuitry in electronic devices are particularly resilient to variations in field-effect transistor (FET) resistance with temperature, gate drive, and/or process shift; variations in printed circuit board (PCB) resistance; and variations in integrated circuit (IC) trip voltages.
    Type: Grant
    Filed: May 27, 2016
    Date of Patent: September 25, 2018
    Assignee: Apple Inc.
    Inventors: Karthik Kadirvel, Soundararajan Manthiri
  • Publication number: 20180254641
    Abstract: Battery packs that include multiple battery cells that may be monitored using a reduced amount of circuitry and battery systems that may account for battery cell changes over aging and temperature.
    Type: Application
    Filed: July 15, 2017
    Publication date: September 6, 2018
    Applicant: Apple Inc.
    Inventors: Karthik Kadirvel, Ankur Gupta, Hua Chen, Christopher C. Branson, David M. DeMuro, Alessandro Pelosi
  • Publication number: 20180080992
    Abstract: A battery management unit may measure a battery voltage of a battery across a first pair of nodes of the battery management unit to produce a first battery measurement and a current of the battery based on a voltage across a second pair of nodes of the battery management unit. Then, the battery management unit may generate a threshold current for a comparator in the battery management unit based on the current, where the threshold current is a sum of the current and a predetermined reference current associated with a predetermined operating profile of an application. Next, the battery management unit may measure the first voltage when the current equals the threshold current to produce a second battery measurement. Moreover, the battery management unit may calculate a model parameter in a model of the battery based on the first voltage measurement, the second voltage measurement, and the predetermined reference current.
    Type: Application
    Filed: February 27, 2017
    Publication date: March 22, 2018
    Inventors: Karthik KADIRVEL, Saroj SAHU
  • Publication number: 20180034288
    Abstract: This disclosure describes a battery pack that includes a plurality of asymmetrical banks, with different capacities and/or voltages, and multiple taps, coupled to the corresponding banks, to power electrical loads. The battery pack also comprise a balancing circuit and a battery management unit. The battery pack may regulate voltages among the banks and/or balance the states of charge among the asymmetrical banks, by moving charges among the banks, by controlling one or more converters. The battery pack monitors the status of its banks and communicate with a host system via the battery management unit. Based on the monitored information and/or communication, the battery management unit generates control signals to drive the one or more converters.
    Type: Application
    Filed: July 28, 2017
    Publication date: February 1, 2018
    Inventors: Thomas C. Greening, Karthik Kadirvel, Gary L. Stirk, Saroj K. Sahu, Kamran M. Hasan
  • Patent number: 9843204
    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: Grant
    Filed: December 7, 2015
    Date of Patent: December 12, 2017
    Assignee: Texas Instruments Incorporated
    Inventors: Karthik Kadirvel, Steve Harrell, Brian Lum-Shue-Chan
  • Patent number: 9813063
    Abstract: An apparatus may include one or more registers configured to store a plurality of values, and an analog-to-digital converter (ADC). Each value of the plurality of values may correspond to a characteristic of a transistor at a respective temperature value. The ADC may be configured to generate a digital value corresponding to a difference in voltage levels between a first terminal and a second terminal of the transistor. The apparatus may further include a sensor configured to measure a temperature, and control logic configured to generate a first voltage level at a control terminal of the transistor and receive the digital value from the ADC. The control logic may be further configured to determine, during a first operational mode, a current passing through the transistor dependent upon the digital value, at least one value of the plurality of values, and the temperature.
    Type: Grant
    Filed: May 6, 2015
    Date of Patent: November 7, 2017
    Assignee: Apple Inc.
    Inventors: Gary L. Stirk, Karthik Kadirvel
  • Publication number: 20160380447
    Abstract: This disclosure relates generally to the field of providing highly accurate over current fault protection in charging systems and, more particularly, to systems in which the charge over current protection (COCP) and discharge over current protection (DOCP) circuitry in electronic devices are particularly resilient to variations in field-effect transistor (FET) resistance with temperature, gate drive, and/or process shift; variations in printed circuit board (PCB) resistance; and variations in integrated circuit (IC) trip voltages.
    Type: Application
    Filed: May 27, 2016
    Publication date: December 29, 2016
    Inventors: Karthik Kadirvel, Soundararajan Manthiri
  • Publication number: 20160336773
    Abstract: In general, techniques are disclosed for providing short circuit protection to a battery pack having a number of battery cells, at least some of which are connected in parallel. Short circuit protection is provided by using pairs of electronic switches (e.g., integrated circuits consisting of a pair of transistors designed as battery charge/discharge switches) serially connected between one terminal of a battery cell and a battery pack's common node—a position which is upstream of conventional battery pack fault controllers. The state of all such switches may be controlled by a control unit that is also upstream of a conventional fault controller. The combination of switch pairs and control unit can provide a battery pack with over current (short circuit) protection without the use of thermal cutoff devises. The described devices and systems can also provide over voltage, under voltage and over temperature protection.
    Type: Application
    Filed: May 13, 2016
    Publication date: November 17, 2016
    Inventors: Karthik Kadirvel, Soundararajan Manthiri
  • Patent number: 9413354
    Abstract: A system may include a plurality of units, wherein each unit has a respective common mode voltage terminal, communication up terminal, and communication down terminal. A first unit of the plurality of units may be configured to generate a first plurality of currents on its communication up terminal, wherein the first plurality of currents corresponds to a first plurality of bits. A second unit of the plurality of units may be configured to receive the first plurality of currents on its respective communication down terminal, and maintain a voltage level at its respective communication down terminal during reception of the first plurality of currents. The voltage level may be equal to a common mode voltage of the respective common mode voltage terminal of the second unit.
    Type: Grant
    Filed: May 6, 2015
    Date of Patent: August 9, 2016
    Assignee: Apple Inc.
    Inventors: Gary L. Stirk, Karthik Kadirvel
  • Publication number: 20160182047
    Abstract: A system may include a plurality of units, wherein each unit has a respective common mode voltage terminal, communication up terminal, and communication down terminal. A first unit of the plurality of units may be configured to generate a first plurality of currents on its communication up terminal, wherein the first plurality of currents corresponds to a first plurality of bits. A second unit of the plurality of units may be configured to receive the first plurality of currents on its respective communication down terminal, and maintain a voltage level at its respective communication down terminal during reception of the first plurality of currents. The voltage level may be equal to a common mode voltage of the respective common mode voltage terminal of the second unit.
    Type: Application
    Filed: May 6, 2015
    Publication date: June 23, 2016
    Inventors: Gary L. Stirk, Karthik Kadirvel
  • Publication number: 20160178705
    Abstract: An apparatus may include one or more registers configured to store a plurality of values, and an analog-to-digital converter (ADC). Each value of the plurality of values may correspond to a characteristic of a transistor at a respective temperature value. The ADC may be configured to generate a digital value corresponding to a difference in voltage levels between a first terminal and a second terminal of the transistor. The apparatus may further include a sensor configured to measure a temperature, and control logic configured to generate a first voltage level at a control terminal of the transistor and receive the digital value from the ADC. The control logic may be further configured to determine, during a first operational mode, a current passing through the transistor dependent upon the digital value, at least one value of the plurality of values, and the temperature.
    Type: Application
    Filed: May 6, 2015
    Publication date: June 23, 2016
    Inventors: Gary L. Stirk, Karthik Kadirvel
  • Publication number: 20160164319
    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: December 7, 2015
    Publication date: June 9, 2016
    Inventors: Karthik Kadirvel, Steve Harrell, Brian Lum-Shue-Chan
  • Publication number: 20160093921
    Abstract: A battery system has positive and negative pack terminals, and positive and negative sense terminals. An electrochemical cell assembly has positive and negative cell terminals. An electrically conductive power path has a positive leg that connects the positive cell terminal to the positive pack terminal, and a negative leg that connects the negative cell terminal to the negative pack terminal. A power switch circuit is connected in the power path. An electrically conductive sense path separate from the power path has a positive leg that connects the positive cell terminal to the positive sense terminal, and a negative leg that connects to the negative sense terminal. A sense switch circuit is connected in the sense path. Other embodiments are also described and claimed.
    Type: Application
    Filed: July 20, 2015
    Publication date: March 31, 2016
    Inventors: Karthik Kadirvel, Soundararajan Manthiri, Salvatore Reddiconto, Liquan Tan
  • Patent number: 9209632
    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: Grant
    Filed: May 20, 2013
    Date of Patent: December 8, 2015
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Karthik Kadirvel, III, Steve Harrell, Brian Lum-Shue-Chan