Patents by Inventor Randy G. Flatness

Randy G. Flatness 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: 7812585
    Abstract: A voltage regulator includes an input connectable to a voltage source and an output connectable to a load. The voltage regulator includes an inductor coupled to the output, a switch between the input and the inductor, and a current control loop configured to control the duty cycle of the switch to regulate voltage at the output, wherein the duty cycle being based on both a peak and valley threshold level of current flowing through the inductor.
    Type: Grant
    Filed: May 29, 2007
    Date of Patent: October 12, 2010
    Assignee: Linear Technology Corporation
    Inventors: Xunwei Zhou, Randy G. Flatness
  • Patent number: 7466112
    Abstract: A switched regulator circuit provides step-up and step-down operation in which the level of the input voltage can be greater, equal to, or less than a preset controlled output voltage. A four switch arrangement or two switch arrangement provides buck, boost, and buck-boost regulation under variable frequency valley-peak current mode control. A single sense resistor may be utilized for sensing inductor current during each duty cycle.
    Type: Grant
    Filed: February 8, 2005
    Date of Patent: December 16, 2008
    Assignee: Linear Technology Corporation
    Inventors: Xunwei Zhou, Randy G. Flatness
  • Publication number: 20080297122
    Abstract: A voltage regulator includes an input connectable to a voltage source and an output connectable to a load. The voltage regulator includes an inductor coupled to the output, a switch between the input and the inductor, and a current control loop configured to control the duty cycle of the switch to regulate voltage at the output, wherein the duty cycle being based on both a peak and valley threshold level of current flowing through the inductor.
    Type: Application
    Filed: May 29, 2007
    Publication date: December 4, 2008
    Inventors: Xunwei Zhou, Randy G. Flatness
  • Patent number: 7394231
    Abstract: A switched regulator circuit provides step-up and step-down operation in which the level of the input voltage can be greater, equal to, or less than a preset controlled output voltage. A four switch arrangement or two switch arrangement provides buck, boost, and buck-boost regulation under constant frequency valley-peak current mode control. A single sense resistor may be utilized for sensing inductor current during only a short period during each duty cycle. As an alternative to the sense resistor, the switches themselves can be used to sense current during operation.
    Type: Grant
    Filed: February 8, 2005
    Date of Patent: July 1, 2008
    Assignee: Linear Technology Corporation
    Inventors: Randy G. Flatness, Xunwei Zhou
  • Patent number: 7365525
    Abstract: A four switch voltage converter is regulated for buck mode and boost mode under constant frequency valley-peak current mode control. Protection circuits are responsive to output voltage and regulator current to prevent excessive current that otherwise might result from abnormally low output voltage short circuit, or spurious switching abnormalities during low duty cycle operation. The regulator control circuit is responsive to the protection circuits to automatically connect a regulator inductor between a common potential and the output to limit current.
    Type: Grant
    Filed: February 8, 2005
    Date of Patent: April 29, 2008
    Assignee: Linear Technology Corporation
    Inventors: Xunwei Zhou, Randy G. Flatness
  • Patent number: 7256570
    Abstract: A switched regulator circuit provides step-up and step-down operation at high efficiency during light load conditions. Switching loss is reduced in a four switch arrangement by limiting bottom MOSFET switching frequency. The possibility of overcharge in boost mode operation has been avoided by automatically changing to a buck mode operation in response to sensed parameters.
    Type: Grant
    Filed: February 8, 2005
    Date of Patent: August 14, 2007
    Assignee: Linear Technology Corporation
    Inventors: Xunwei Zhou, Randy G. Flatness
  • Patent number: 7170195
    Abstract: A monolithic switching regulator that flexibly distributes its output current among its output channels is provided. The monolithic switching regulator includes one or more additional channels that are externally connected to the output channels for providing additional current partitioning configurations. The external connections may be autosensed or programmed with an additional input pin. A switching logic circuit is provided for distributing the current among the output channels according to their external connections to the additional channels.
    Type: Grant
    Filed: October 8, 2004
    Date of Patent: January 30, 2007
    Assignee: Linear Technology Corporation
    Inventors: Howard H. Haensel, Yuhui Chen, Randy G. Flatness
  • Patent number: 7019497
    Abstract: Methods for synchronizing non-constant frequency switching regulators with a phase locked loop are disclosed. The methods enable non-constant frequency switching regulators to be synchronized with a phase locked loop to achieve constant frequency operation in steady state while retaining the advantages of non-frequency operation to improve transient response and operate over a wider range of duty cycles. In addition, the methods enable multiple non-constant frequency regulators to be synchronized and operated in parallel to deliver higher power levels to the output than a single switching regulator.
    Type: Grant
    Filed: July 2, 2004
    Date of Patent: March 28, 2006
    Assignee: Linear Technology Corporation
    Inventors: Christopher B. Umminger, Randy G. Flatness
  • Patent number: 6774611
    Abstract: Methods for synchronizing non-constant frequency switching regulators with a phase locked loop are disclosed. The methods enable non-constant frequency switching regulators to be synchronized with a phase locked loop to achieve constant frequency operation in steady state while retaining the advantages of non-frequency operation to improve transient response and operate over a wider range of duty cycles. In addition, the methods enable multiple non-constant frequency regulators to be synchronized and operated in parallel to deliver higher power levels to the output than a single switching regulator.
    Type: Grant
    Filed: July 15, 2002
    Date of Patent: August 10, 2004
    Assignee: Linear Technology Corporation
    Inventors: Christopher B. Umminger, Randy G. Flatness
  • Patent number: 6674274
    Abstract: Multiple phase switching regulators with stage shedding are provided. Multiple phase switching regulators of the present invention have a plurality of single phase switching regulators coupled in parallel to an output capacitor. The plurality of single phase switching regulators supply current to a load at a regulated voltage. A comparator monitors the load current and causes one or more of the single phase switching regulators to be OFF at a low load current threshold. At least one of the single phase switching regulators that remains ON increases its output current so that the multiple phase switching regulator output current continues to match the load current. The present invention may include a second comparator that causes additional single phase switching regulators to be OFF at a second low load current threshold that is lower than the first low load current threshold.
    Type: Grant
    Filed: February 8, 2001
    Date of Patent: January 6, 2004
    Assignee: Linear Technology Corporation
    Inventors: Stephen W. Hobrecht, Randy G. Flatness
  • Patent number: 6580258
    Abstract: A circuit and method for controlling a switching voltage regulator having (1) a switch including one or more switching transistors and (2) an output adapted to supply current at a regulated voltage to a load including an output capacitor. The circuit and method generates a control signal to turn said one or more switching transistors OFF under operating conditions when the voltage at the output is capable of being maintained substantially at the regulated voltage by the charge on the output capacitor. Such a circuit and method increases the efficiency of the regulator circuit particularly at low average current levels.
    Type: Grant
    Filed: October 15, 2001
    Date of Patent: June 17, 2003
    Assignee: Linear Technology Corporation
    Inventors: Milton E. Wilcox, Randy G. Flatness
  • Publication number: 20020180413
    Abstract: Methods for synchronizing non-constant frequency switching regulators with a phase locked loop are disclosed. The methods enable non-constant frequency switching regulators to be synchronized with a phase locked loop to achieve constant frequency operation in steady state while retaining the advantages of non-frequency operation to improve transient response and operate over a wider range of duty cycles. In addition, the methods enable multiple non-constant frequency regulators to be synchronized and operated in parallel to deliver higher power levels to the output than a single switching regulator.
    Type: Application
    Filed: July 15, 2002
    Publication date: December 5, 2002
    Applicant: Linear Technology Corporation
    Inventors: Christopher B. Umminger, Randy G. Flatness
  • Patent number: 6476589
    Abstract: Methods for synchronizing non-constant frequency switching regulators with a phase locked loop are disclosed. The methods enable non-constant frequency switching regulators to be synchronized with a phase locked loop to achieve constant frequency operation in steady state while retaining the advantages of non-frequency operation to improve transient response and operate over a wider range of duty cycles. In addition, the methods enable multiple non-constant frequency regulators to be synchronized and operated in parallel to deliver higher power levels to the output than a single switching regulator.
    Type: Grant
    Filed: April 6, 2001
    Date of Patent: November 5, 2002
    Assignee: Linear Technology Corporation
    Inventors: Christopher B. Umminger, Randy G. Flatness
  • Publication number: 20020145409
    Abstract: Methods for synchronizing non-constant frequency switching regulators with a phase locked loop are disclosed. The methods enable non-constant frequency switching regulators to be synchronized with a phase locked loop to achieve constant frequency operation in steady state while retaining the advantages of non-frequency operation to improve transient response and operate over a wider range of duty cycles. In addition, the methods enable multiple non-constant frequency regulators to be synchronized and operated in parallel to deliver higher power levels to the output than a single switching regulator.
    Type: Application
    Filed: April 6, 2001
    Publication date: October 10, 2002
    Applicant: LINEAR TECHNOLOGY CORPORATION
    Inventors: Christopher B. Umminger, Randy G. Flatness
  • Publication number: 20020135338
    Abstract: Multiple phase switching regulators with stage shedding are provided. Multiple phase switching regulators of the present invention have a plurality of single phase switching regulators coupled in parallel to an output capacitor. The plurality of single phase switching regulators supply current to a load at a regulated voltage. A comparator monitors the load current and causes one or more of the single phase switching regulators to be OFF at a low load current threshold. At least one of the single phase switching regulators that remains ON increases its output current so that the multiple phase switching regulator output current continues to match the load current. The present invention may include a second comparator that causes additional single phase switching regulators to be OFF at a second low load current threshold that is lower than the first low load current threshold.
    Type: Application
    Filed: February 8, 2001
    Publication date: September 26, 2002
    Inventors: Stephen W. Hobrecht, Randy G. Flatness
  • Publication number: 20020017897
    Abstract: A circuit and method for controlling a switching voltage regulator having (1) a switch including one or more switching transistors and (2) an output adapted to supply current at a regulated voltage to a load including an output capacitor. The circuit and method generates a control signal to turn said one or more switching transistors OFF under operating conditions when the voltage at the output is capable of being maintained substantially at the regulated voltage by the charge on the output capacitor. Such a circuit and method increases the efficiency of the regulator circuit particularly at low average current levels.
    Type: Application
    Filed: October 15, 2001
    Publication date: February 14, 2002
    Applicant: Linear Technology Corporation
    Inventors: Milton E. Wilcox, Randy G. Flatness
  • Patent number: 6304066
    Abstract: A circuit and method for controlling a switching voltage regulator having (1) a switch including one or more switching transistors and (2) an output adapted to supply current at a regulated voltage to a load including an output capacitor. The circuit and method generates a control signal to turn said one or more switching transistors OFF under operating conditions when the voltage at the output is capable of being maintained substantially at the regulated voltage by the charge on the output capacitor. Such a circuit and method increases the efficiency of the regulator circuit particularly at low average current levels.
    Type: Grant
    Filed: September 14, 1999
    Date of Patent: October 16, 2001
    Assignee: Linear Technology Corporation
    Inventors: Milton E. Wilcox, Randy G. Flatness
  • Patent number: 5994885
    Abstract: A circuit and method for controlling a switching voltage regulator having (1) a switch including one or more switching transistors and (2) an output adapted to supply current at a regulated voltage to a load including an output capacitor. The circuit and method generates a control signal to turn said one or more switching transistors OFF under operating conditions when the voltage at the output is capable of being maintained substantially at the regulated voltage by the charge on the output capacitor. Such a circuit and method increases the efficiency of the regulator circuit particularly at low average current levels.
    Type: Grant
    Filed: November 25, 1997
    Date of Patent: November 30, 1999
    Assignee: Linear Technology Corporation
    Inventors: Milton E. Wilcox, Randy G. Flatness
  • Patent number: 5731694
    Abstract: A circuit and method for controlling a switching voltage regulator having (1) a switch including one or more switching transistors and (2) an output adapted to supply current at a regulated voltage to a load including an output capacitor. The circuit and method generates a control signal to turn said one or more switching transistors OFF under operating conditions when the voltage at the output is capable of being maintained substantially at the regulated voltage by the charge on the output capacitor. Such a circuit and method increases the efficiency of the regulator circuit particularly at low average current levels.
    Type: Grant
    Filed: February 13, 1997
    Date of Patent: March 24, 1998
    Assignee: Linear Technology Corporation
    Inventors: Milton E. Wilcox, Randy G. Flatness
  • Patent number: RE41037
    Abstract: Switching regulator circuits and methods are provided for regulating output voltage that include an adjustable minimum peak inductor current level for Burst Mode in current-mode DC-DC regulators. Minimum peak inductor current level control is achieved during Burst Mode by allowing external control for adjusting the burst threshold level. A single pin can be used to distinguish between forced continuous and Burst Mode as well as set the burst threshold level during Burst Mode, or an alternate method of setting a variable burst threshold level can be implemented in which two pins are used, one for selecting the mode of operation and the other for setting the burst threshold level during Burst Mode. The above principles can be applied to both step-up and step-down regulator circuit configurations, as well as both synchronous switching regulators and non-synchronous switching regulators.
    Type: Grant
    Filed: April 20, 2006
    Date of Patent: December 15, 2009
    Assignee: Linear Technology Corp.
    Inventors: Joey M. Esteves, Randy G. Flatness