Patents by Inventor Michael Eugene Broach

Michael Eugene Broach 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: 7932754
    Abstract: A system, apparatus and method is arranged to adaptively adjust drive signals for a gate controlled switch circuit such that the amount of gate swing automatically changes based on the load conditions. An adaptive gate charge modulation (GCM) technique can be utilized to dynamically adjust the drive signals so that a substantially constant voltage drop is perceived across to a gate controlled switch circuit. The voltage drop across the gate controlled switch circuit can be set to a reference level that is adjusted whenever a change in system conditions are detected. The gate charge can then be adaptively increased and decreased during operation, within maximum and minimum limits, to substantially match the voltage drop of the gate control switch circuit to the reference level.
    Type: Grant
    Filed: August 17, 2006
    Date of Patent: April 26, 2011
    Assignee: National Semiconductor Corporation
    Inventors: Michael Eugene Broach, Michael D. Mulligan
  • Patent number: 7589517
    Abstract: A system, method, and apparatus are arranged to provide adaptive slope compensation in a switching regulator that includes an inductor. A control loop of the switching regulator is responsive to a ramp signal. A ramp generator that includes a capacitor circuit and a current source provides the ramp signal, where at least one of the current level of the current source and the value of the capacitor circuit are adjusted to vary the slope of the ramp signal. The adjustment of the ramp signal is responsive to at least one of: a set point for the output voltage of the switching regulator, a feedback voltage that is related to the output voltage, and a measured parameter associated with the inductor in the switching regulator. By dynamically adjusting the slope of the ramp signal, slope compensation is provided for a range of inductor values that can dynamically change during operation.
    Type: Grant
    Filed: July 23, 2007
    Date of Patent: September 15, 2009
    Assignee: National Semiconductor Corporation
    Inventors: Michael Eugene Broach, Frank John De Stasi
  • Patent number: 7583138
    Abstract: A system and a method are disclosed for controlling an error amplifier between control mode changes. An error amplifier comprises a first stage that comprises a first current source and a second stage that comprises a second current source and at least one compensation component that is connected to the first stage through a signal line. A buffer circuit is connected between the signal line and the at least one compensation component and a switch circuit is connected between the buffer circuit and the at least one compensation component. When switched in to the error amplifier the buffer circuit provides a value of current to the at least one compensation component that is larger than a value of current that is provided to the at least one compensation component from the signal line. This increases the slew rate of the error amplifier during a pulse frequency modulation control mode.
    Type: Grant
    Filed: November 9, 2007
    Date of Patent: September 1, 2009
    Assignee: National Semiconductor Corporation
    Inventors: Frank DeStasi, Michael Eugene Broach
  • Patent number: 7479778
    Abstract: A system, method, and apparatus are arranged to provide adaptive slope compensation in a switching regulator that includes an inductor. A control loop of the switching regulator is responsive to a ramp signal. A ramp generator that includes a capacitor circuit and a current source provides the ramp signal, where at least one of the current level of the current source and the value of the capacitor circuit are adjusted to vary the slope of the ramp signal. The adjustment of the ramp signal is responsive to at least one of: a set point for the output voltage of the switching regulator, a feedback voltage that is related to the output voltage, and a measured parameter associated with the inductor in the switching regulator. By dynamically adjusting the slope of the ramp signal, slope compensation is provided for a range of inductor values that can dynamically change during operation.
    Type: Grant
    Filed: July 23, 2007
    Date of Patent: January 20, 2009
    Assignee: National Semiconductor Corporation
    Inventors: Michael Eugene Broach, Frank John De Stasi
  • Patent number: 7307412
    Abstract: A system and method measures parameters associated with an inductor such as in a switching converter. The inductance value can be determined by monitoring voltages and currents associated with the inductor when a measurement mode is activated. In one example, the measurement is provided by a signal processing system that includes an analog differentiator. In another example, the measurement is provided by a signal processing system that converts the analog measurement voltages into digital quantities that are analyzed in the digital domain. The value of the inductance value is determined by calculating of ?VL and ?IL/?t. The saturation point in the inductance is located by measuring the change in slew rate of the inductance during the measurement mode. Average values for the inductor and the slew rate can be determined using digital techniques. Other parameters such as current limit and on-time of the inductor can be adjusted by this methodology.
    Type: Grant
    Filed: March 10, 2006
    Date of Patent: December 11, 2007
    Assignee: National Semiconductor Corporation
    Inventor: Michael Eugene Broach
  • Patent number: 7265530
    Abstract: A system, method, and apparatus are arranged to provide adaptive slope compensation in a switching regulator that includes an inductor. A control loop of the switching regulator is responsive to a ramp signal. A ramp generator that includes a capacitor circuit and a current source provides the ramp signal, where at least one of the current level of the current source and the value of the capacitor circuit are adjusted to vary the slope of the ramp signal. The adjustment of the ramp signal is responsive to at least one of: a set point for the output voltage of the switching regulator, a feedback voltage that is related to the output voltage, and a measured parameter associated with the inductor in the switching regulator. By dynamically adjusting the slope of the ramp signal, slope compensation is provided for a range of inductor values that can dynamically change during operation.
    Type: Grant
    Filed: February 17, 2004
    Date of Patent: September 4, 2007
    Assignee: National Semiconductor Corporation
    Inventors: Michael Eugene Broach, Frank John De Stasi
  • Patent number: 7042207
    Abstract: A system and method measures parameters associated with an inductor such as in a switching converter. The inductance value can be determined by monitoring voltages and currents associated with the inductor when a measurement mode is activated. In one example, the measurement is provided by a signal processing system that includes an analog differentiator. In another example, the measurement is provided by a signal processing system that converts the analog measurement voltages into digital quantities that are analyzed in the digital domain. The value of the inductance value is determined by calculating of ?VL and ?IL/?t. The saturation point in the inductance is located by measuring the change in slew rate of the inductance during the measurement mode. Average values for the inductor and the slew rate can be determined using digital techniques. Other parameters such as current limit and on-time of the inductor can be adjusted by this methodology.
    Type: Grant
    Filed: November 7, 2003
    Date of Patent: May 9, 2006
    Assignee: National Semiconductor Corporation
    Inventor: Michael Eugene Broach
  • Patent number: 7000128
    Abstract: The present invention increases power efficiency in power FET applications with varying loads. A constant frequency mode can be used without detracting from efficiency. This is accomplished by reducing repetitive gate charge power losses. The present invention controls the channel impedance of the FET using a timed tri-state driver to drive a level of charge associated with the gate of the FET that is appropriate to the load requirements. When the voltage level at the FET gate reaches the appropriate level, the driver is tri-stated, so that the gate does not continue to charge.
    Type: Grant
    Filed: December 30, 2002
    Date of Patent: February 14, 2006
    Assignee: National Semiconductor Corporation
    Inventor: Michael Eugene Broach
  • Patent number: 6969976
    Abstract: A system, method, and apparatus are arranged to provide for current limit adjustments in a switching regulator that includes an inductor. A switched voltage divider circuit is selectively activated according to the actuation of various switching circuits in the regulator. The output of the switched voltage divider circuit is compared to a reference signal from a reference circuit to determine when a current limit is reached. At least one of the voltage divider ratio and the reference signal is adjustable in response to measurements related to the inductor saturation such that the current limit is changed to match inductor characteristics.
    Type: Grant
    Filed: June 4, 2004
    Date of Patent: November 29, 2005
    Assignee: National Semiconductor Corporation
    Inventors: Michael Eugene Broach, Frank John De Stasi
  • Patent number: 6952093
    Abstract: A system, method, and apparatus are arranged to provide small-signal compensation in a switching regulator that includes an inductor. A zero adjustment circuit is included in the system to introduce at least one zero in the closed-loop transfer function associated with the regulator. The zero adjustment circuit is responsive to a measurement signal, which is associated with one or more measured parameters associated with the inductor. By changing the location of at least one zero in response to the measurement signal it is possible to dynamically change the compensation based on variations in the inductance of the inductor. The zero adjustment circuit may be provided as a portion of the controller block of the regulator, or as a separate feedback circuit. The zero adjustment circuit can be implemented digitally as a portion of a DSP block, or as an analog function as may be desired in a particular system.
    Type: Grant
    Filed: February 17, 2004
    Date of Patent: October 4, 2005
    Assignee: National Semiconductor Corporation
    Inventors: Michael Eugene Broach, Frank John De Stasi
  • Patent number: 6934779
    Abstract: An integrated circuit is configured to receive encoded digital data from a system controller over a single signal line. The system controller encodes the digital data into a singular analog quantity such as a voltage, a current, a sine wave frequency, a sine wave amplitude, a pulse train frequency, or a pulse train duty cycle. The encoded digital data is transmitted to the signal line. The integrated circuit decodes the digital data from the signal line. The decoded digital data is employed by the integrated circuit to adjust one or more parameters of the integrated circuit. In one example, one or more parameters may be adjusted to select various operating modes for the integrated circuit. The singular analog quantity encoding/decoding methodology may be extended to more than one signal line when desirable.
    Type: Grant
    Filed: April 21, 2003
    Date of Patent: August 23, 2005
    Assignee: National Semiconductor Corporation
    Inventor: Michael Eugene Broach
  • Patent number: 6806695
    Abstract: Optimization of a parameter can be achieved by a servo loop having a temperature sensor, a temperature change detector, and a parameter adjuster. The temperature sensor monitors the temperature of an electronic device while the parameter is varied. The temperature change detector detects whether the electronic device temperature is increasing or decreasing. The parameter has a value associated with minimum power consumption when the monitored temperature reaches a minimum. The parameter is adjusted dynamically to a new preferred value as operating conditions of the electronic device change.
    Type: Grant
    Filed: March 31, 2003
    Date of Patent: October 19, 2004
    Assignee: National Semiconductor Corporation
    Inventors: Michael Eugene Broach, Barry James Culpepper
  • Patent number: 6600639
    Abstract: An integrated circuit system and method provides a reliable low voltage reference including undervoltage lockout capabilities that prevent a premature or false response. A physical constant trigger circuit initiates a response based upon a physical constant (e.g. a stable point associated with a voltage summation in a transistor circuit with components configured to produce equal and opposite temperature coefficients). A response includes changing polarities of the transistor circuit at a predetermined inflection point. A comparator compares signals from the physical constant trigger circuit and determines when a change occurs in the response. A voltage divider provides a varying voltage to the physical constant trigger and when the voltage level corresponds to the physical constant it is utilized as the reference voltage. An input signal port conveys an input signal to the voltage divider and output port conveys an indication of the response (e.g., a desired reference voltage is available).
    Type: Grant
    Filed: June 14, 2001
    Date of Patent: July 29, 2003
    Assignee: National Semiconductor Corporation
    Inventors: Siew Siong Teo, Michael Eugene Broach, Richard Frank