Patents by Inventor Sameer G. Kelkar

Sameer G. Kelkar 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: 9941800
    Abstract: The disclosed embodiments provide a system that operates switched-mode power supplies, such as flyback converters. The power supplies may comprise isolated or non-isolated power converters. During operation, the system senses an on-time of a primary switch in the power converter. Upon detecting that the on-time does not exceed an on-time threshold within a first pre-specified period that spans one or more switching cycles, the system extends the on-time during a subsequent switching cycle to at least meet the on-time threshold. The system may then measure the voltage on one or more reference windings of the power converter during the on-time of the subsequent switching cycle, wherein the reference winding may comprise, e.g., an auxiliary winding of the primary winding of the power converter or a secondary winding of the power converter (e.g., in the case of isolated power converters utilizing a transformer).
    Type: Grant
    Filed: September 2, 2015
    Date of Patent: April 10, 2018
    Assignee: Apple Inc.
    Inventors: Juan Carlos Pastrana, Manisha P. Pandya, Sameer G. Kelkar, Nicholas A. Sims
  • Publication number: 20160065080
    Abstract: The disclosed embodiments provide a system that operates switched-mode power supplies, such as flyback converters. The power supplies may comprise isolated or non-isolated power converters. During operation, the system senses an on-time of a primary switch in the power converter. Upon detecting that the on-time does not exceed an on-time threshold within a first pre-specified period that spans one or more switching cycles, the system extends the on-time during a subsequent switching cycle to at least meet the on-time threshold. The system may then measure the voltage on one or more reference windings of the power converter during the on-time of the subsequent switching cycle, wherein the reference winding may comprise, e.g., an auxiliary winding of the primary winding of the power converter or a secondary winding of the power converter (e.g., in the case of isolated power converters utilizing a transformer).
    Type: Application
    Filed: September 2, 2015
    Publication date: March 3, 2016
    Inventors: Juan Carlos Pastrana, Manisha P. Pandya, Sameer G. Kelkar, Nicholas A. Sims
  • Patent number: 7624360
    Abstract: A method and system for feedback circuit design are disclosed. In one aspect, a method of feedback circuit design includes simulating a reference circuit design having a feedback stage at a target crossover frequency, determining an initial phase margin at the target crossover frequency, and adding an impedance network to the feedback stage if the initial phase margin is less than a threshold phase margin. The design of the impedance network is determined such that the initial phase margin is increased.
    Type: Grant
    Filed: November 13, 2006
    Date of Patent: November 24, 2009
    Assignee: Power Integrations, Inc.
    Inventors: Arkady Akselrod, Sameer G. Kelkar
  • Publication number: 20080115095
    Abstract: A method and system for feedback circuit design are disclosed. In one aspect, a method of feedback circuit design includes simulating a reference circuit design having a feedback stage at a target crossover frequency, determining an initial phase margin at the target crossover frequency, and adding an impedance network to the feedback stage if the initial phase margin is less than a threshold phase margin. The design of the impedance network is determined such that the initial phase margin is increased.
    Type: Application
    Filed: November 13, 2006
    Publication date: May 15, 2008
    Inventors: Arkady Akselrod, Sameer G. Kelkar