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).
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Patent number: 10724978Abstract: 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: GrantFiled: September 28, 2018Date of Patent: July 28, 2020Assignee: Apple Inc.Inventors: Saroj K. Sahu, Karthik Kadirvel
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Patent number: 10355497Abstract: 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: GrantFiled: May 13, 2016Date of Patent: July 16, 2019Assignee: Apple Inc.Inventors: Karthik Kadirvel, Soundararajan Manthiri
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Publication number: 20190101501Abstract: 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: ApplicationFiled: September 28, 2018Publication date: April 4, 2019Inventors: Saroj K. SAHU, Karthik KADIRVEL
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Patent number: 10236694Abstract: 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: GrantFiled: July 28, 2017Date of Patent: March 19, 2019Assignee: Apple Inc.Inventors: Thomas C. Greening, Karthik Kadirvel, Gary L. Stirk, Saroj K. Sahu, Kamran M. Hasan
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Patent number: 10211653Abstract: 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: GrantFiled: July 15, 2017Date of Patent: February 19, 2019Assignee: Apple Inc.Inventors: Karthik Kadirvel, Ankur Gupta, Hua Chen, Christopher C. Branson, David M. DeMuro, Alessandro Pelosi
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Publication number: 20180337537Abstract: 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: ApplicationFiled: July 31, 2018Publication date: November 22, 2018Inventors: Karthik Kadirvel, Soundararajan Manthiri
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Patent number: 10084326Abstract: 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: GrantFiled: May 27, 2016Date of Patent: September 25, 2018Assignee: Apple Inc.Inventors: Karthik Kadirvel, Soundararajan Manthiri
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Publication number: 20180254641Abstract: 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: ApplicationFiled: July 15, 2017Publication date: September 6, 2018Applicant: Apple Inc.Inventors: Karthik Kadirvel, Ankur Gupta, Hua Chen, Christopher C. Branson, David M. DeMuro, Alessandro Pelosi
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Publication number: 20180080992Abstract: 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: ApplicationFiled: February 27, 2017Publication date: March 22, 2018Inventors: Karthik KADIRVEL, Saroj SAHU
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Publication number: 20180034288Abstract: 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: ApplicationFiled: July 28, 2017Publication date: February 1, 2018Inventors: Thomas C. Greening, Karthik Kadirvel, Gary L. Stirk, Saroj K. Sahu, Kamran M. Hasan
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Patent number: 9843204Abstract: 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: GrantFiled: December 7, 2015Date of Patent: December 12, 2017Assignee: Texas Instruments IncorporatedInventors: Karthik Kadirvel, Steve Harrell, Brian Lum-Shue-Chan
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Patent number: 9813063Abstract: 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: GrantFiled: May 6, 2015Date of Patent: November 7, 2017Assignee: Apple Inc.Inventors: Gary L. Stirk, Karthik Kadirvel
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Publication number: 20160380447Abstract: 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: ApplicationFiled: May 27, 2016Publication date: December 29, 2016Inventors: Karthik Kadirvel, Soundararajan Manthiri
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Publication number: 20160336773Abstract: 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: ApplicationFiled: May 13, 2016Publication date: November 17, 2016Inventors: Karthik Kadirvel, Soundararajan Manthiri
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Patent number: 9413354Abstract: 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: GrantFiled: May 6, 2015Date of Patent: August 9, 2016Assignee: Apple Inc.Inventors: Gary L. Stirk, Karthik Kadirvel
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Publication number: 20160182047Abstract: 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: ApplicationFiled: May 6, 2015Publication date: June 23, 2016Inventors: Gary L. Stirk, Karthik Kadirvel
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Publication number: 20160178705Abstract: 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: ApplicationFiled: May 6, 2015Publication date: June 23, 2016Inventors: Gary L. Stirk, Karthik Kadirvel
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Publication number: 20160164319Abstract: 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: ApplicationFiled: December 7, 2015Publication date: June 9, 2016Inventors: Karthik Kadirvel, Steve Harrell, Brian Lum-Shue-Chan
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Publication number: 20160093921Abstract: 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: ApplicationFiled: July 20, 2015Publication date: March 31, 2016Inventors: Karthik Kadirvel, Soundararajan Manthiri, Salvatore Reddiconto, Liquan Tan
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Patent number: 9209632Abstract: 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: GrantFiled: May 20, 2013Date of Patent: December 8, 2015Assignee: TEXAS INSTRUMENTS INCORPORATEDInventors: Karthik Kadirvel, III, Steve Harrell, Brian Lum-Shue-Chan