Patents by Inventor John Christopher Canfield

John Christopher Canfield 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: 8368365
    Abstract: A buck-boost converter with a switch controller may cause switches A, B, C, and/or D to cyclically close such that switches B and C are closed during at least one interval of each cycle during both the buck and boost modes of operation. The switch controller may in addition or instead cause switches A, B, C, and/or D to cyclically close based on a control signal such that switches A and D are closed during an interval of each cycle and such that these intervals are never both simultaneously modulated by a small change in the control signal during any mode of operation.
    Type: Grant
    Filed: December 18, 2009
    Date of Patent: February 5, 2013
    Assignee: Linear Technology Corporation
    Inventors: John Christopher Canfield, James Edward Wells
  • Patent number: 8310216
    Abstract: A synchronous boost DC/DC conversion system comprises an input for receiving a DC input voltage, an output for producing a DC output voltage, a power switch controllable to adjust an output signal of the conversion system, and an inductor coupled to the input. A synchronous rectifier is configurable to create a conduction path between the inductor and the output to provide the inductor discharge. A control circuit is provided for controlling the synchronous rectifier as the input voltage approaches the output voltage, so as to adjust average impedance of the conduction path over a discharge period of the inductor.
    Type: Grant
    Filed: October 3, 2011
    Date of Patent: November 13, 2012
    Assignee: Linear Technology Corporation
    Inventors: John Christopher Canfield, David Charles Salerno
  • Publication number: 20120019228
    Abstract: A synchronous boost DC/DC conversion system comprises an input for receiving a DC input voltage, an output for producing a DC output voltage, a power switch controllable to adjust an output signal of the conversion system, and an inductor coupled to the input. A synchronous rectifier is configurable to create a conduction path between the inductor and the output to provide the inductor discharge. A control circuit is provided for controlling the synchronous rectifier as the input voltage approaches the output voltage, so as to adjust average impedance of the conduction path over a discharge period of the inductor.
    Type: Application
    Filed: October 3, 2011
    Publication date: January 26, 2012
    Applicant: Linear Technology Corporation
    Inventors: John Christopher Canfield, David Charles Salerno
  • Patent number: 8063615
    Abstract: A synchronous boost DC/DC conversion system comprises an input for receiving a DC input voltage, an output for producing a DC output voltage, a power switch controllable to adjust an output signal of the conversion system, and an inductor coupled to the input. A synchronous rectifier is configurable to create a conduction path between the inductor and the output to provide the inductor discharge. A control circuit is provided for controlling the synchronous rectifier as the input voltage approaches the output voltage, so as to adjust average impedance of the conduction path over a discharge period of the inductor.
    Type: Grant
    Filed: March 27, 2007
    Date of Patent: November 22, 2011
    Assignee: Linear Technology Corporation
    Inventors: John Christopher Canfield, David Charles Salerno
  • Publication number: 20110148373
    Abstract: A buck-boost converter with a switch controller may cause switches A, B, C, and/or D to cyclically close such that switches B and C are closed during at least one interval of each cycle during both the buck and boost modes of operation. The switch controller may in addition or instead cause switches A, B, C, and/or D to cyclically close based on a control signal such that switches A and D are closed during an interval of each cycle and such that these intervals are never both simultaneously modulated by a small change in the control signal during any mode of operation.
    Type: Application
    Filed: December 18, 2009
    Publication date: June 23, 2011
    Applicant: Linear Technology Corporation
    Inventors: John Christopher Canfield, James Edward Wells
  • Publication number: 20080239774
    Abstract: A synchronous boost DC/DC conversion system comprises an input for receiving a DC input voltage, an output for producing a DC output voltage, a power switch controllable to adjust an output signal of the conversion system, and an inductor coupled to the input. A synchronous rectifier is configurable to create a conduction path between the inductor and the output to provide the inductor discharge. A control circuit is provided for controlling the synchronous rectifier as the input voltage approaches the output voltage, so as to adjust average impedance of the conduction path over a discharge period of the inductor.
    Type: Application
    Filed: March 27, 2007
    Publication date: October 2, 2008
    Inventors: John Christopher Canfield, David Charles Salerno