Patents by Inventor Charles E. Hawkes

Charles E. Hawkes 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: 7200014
    Abstract: A signal processing methodology and circuit for supplying bias power and duty cycle information across an isolation barrier, wherein, at an input side of the isolation barrier at least one input signal carrying input duty cycle information, together with DC bias power, is received and encoded on a constant repetition rate, constant duty cycle carrier waveform. Encoding is carried out by an encoder implemented to encode the carrier waveform with a marker, such as a waveform discontinuity, at a timing corresponding to the input duty cycle information, and wherein the presence of the marker leaves the average value of the carrier waveform unaffected. At the output side of the isolation barrier, the duty cycle information may be received by a decoder, the input duty cycle information detected to reconstruct the at least one input signal, and optionally DC bias power extracted from the carrier waveform.
    Type: Grant
    Filed: November 22, 2004
    Date of Patent: April 3, 2007
    Assignee: Linear Technology Corporation
    Inventors: Charles E. Hawkes, Arthur W. Kelley
  • Patent number: 6278263
    Abstract: A multi-phase DC/DC converter having an output voltage and including a plurality of converter channels. Each converter channel includes a converter channel input and a converter channel output. Each converter channel is configured for generating a converter channel current and for adjusting said converter channel current in response to a control signal electrically connected to each converter channel input. A control circuit generates an error signal representative of a comparison of the converter output voltage to a reference voltage. The control circuit includes a plurality of control circuit channels, each of which correspond to a converter channel. Each control circuit channel generates a channel current signal representative of a corresponding converter channel current, and generates a differential channel current signal representative of a comparison of the channel current signal to an average current signal.
    Type: Grant
    Filed: June 12, 2000
    Date of Patent: August 21, 2001
    Assignee: Intersil Corporation
    Inventors: Michael M. Walters, Charles E. Hawkes, Robert H. Isham
  • Patent number: 6246220
    Abstract: A DC to DC buck pulse width modulator converter circuit includes an input, a high side output and a low side output. A high side switch is electrically connected between a common output node and a voltage supply, and controls a flow of current therethrough dependent upon the high side output. A low side switch is electrically connected between the common output node and ground, and controls a flow of current therethrough dependent upon the low side output. A virtual ground amplifier includes a second input electrically connected to ground. A current feedback resistor is electrically connected intermediate the common output node and a first input of the virtual ground amplifier. A variable impedance component is electrically connected to an output of the virtual ground amplifier and to the first input of the virtual ground amplifier. The impedance of the variable impedance component is varied dependent upon the output of the virtual ground amplifier.
    Type: Grant
    Filed: August 7, 2000
    Date of Patent: June 12, 2001
    Assignee: Intersil Corporation
    Inventors: Robert H. Isham, Charles E. Hawkes, Michael M. Walters
  • Patent number: 6181120
    Abstract: A DC/DC converter has an output voltage and sources an output current to a load. The DC/DC converter includes an error amplifier with a reference input and a summing input. The reference input is electrically connected to a reference voltage. The summing input is electrically connected to the output voltage and the output current. The summing input is configured for adding together the output voltage and the output current. The error amplifier issues an error signal and adjusts the error signal dependent at least in part upon the output voltage and the output current. A comparator receives the error signal. The comparator has a ramp input electrically connected to a voltage ramp signal. The comparator issues an output signal that is based at least in part upon said error input. A power switch has an on condition and an off condition, and supplies dc current to the load when in the on condition. The power switch has a control input electrically connected to the comparator output signal.
    Type: Grant
    Filed: June 9, 2000
    Date of Patent: January 30, 2001
    Assignee: Intersil Corporation
    Inventors: Charles E. Hawkes, Michael M. Walters, Robert H. Isham
  • Patent number: 6058030
    Abstract: A circuit includes a plurality of DC-to-DC converter circuits and separates in time switching of the respective power switches of the DC-to-DC converter circuits which would otherwise be switching at nearly a same time, such as based upon a same desired output level. The switching time may be separated by inverting a periodic control waveform of at least one of the DC-to-DC converter circuits. The multiple output DC-to-DC converter circuit thereby provides an increased noise margin and operates with greater accuracy and stability. The circuit may also determine when the DC-to-DC converter circuits would otherwise be switching at nearly the same time, and activate the switching time separation responsive thereto. For example, the determination may be made based upon a selectable output level being within a predetermined range of at least one other output level.
    Type: Grant
    Filed: November 20, 1997
    Date of Patent: May 2, 2000
    Assignee: Intersil Corporation
    Inventors: Charles E. Hawkes, Michael M. Walters, Thomas A. Jochum
  • Patent number: 6005303
    Abstract: A linear voltage regulator includes a pass device for supplying current to a load, and an error amplifier for generating a control signal for controlling the pass device for regulating an output voltage at the load. The error amplifier is connected to a first power supply having a first voltage and a second power supply having a second voltage greater than the first voltage. The error amplifier preferably includes an output stage for providing a greater amount of current to the pass device from the first power supply than from the second power supply when the control signal is below a predetermined value, and for providing a greater amount of current to the pass device from the second power supply than the first power supply when the control signal is above the predetermined value. The predetermined value may be slightly above the typical drive or control voltage needed for a bipolar pass device.
    Type: Grant
    Filed: June 30, 1998
    Date of Patent: December 21, 1999
    Assignee: Intersil Corporation
    Inventors: Charles E. Hawkes, Thomas A. Jochum
  • Patent number: 5982160
    Abstract: A DC-to-DC power converter includes at least one power switch, a pulse width modulation circuit for generating control pulses for the at least one power switch, an output inductor connected to the at least one power switch, and a current sensor connected in parallel with the inductor for sensing current passing through the inductor. The current sensor preferably includes a resistor and a capacitor connected together in series. The current sensor is connected to a peak current control loop circuit cooperating with the pulse width modulation circuit for controlling the at least one power switch responsive to the current sensor. The resistor and capacitor preferably have respective values so that the current sensor is a substantially instantaneous current sensor. The output inductor has an inductance and a direct current (DC) resistance defining a first time constant. In one embodiment, the resistor and capacitor of the current sensor define a second time constant within a predetermined range of each other.
    Type: Grant
    Filed: December 24, 1998
    Date of Patent: November 9, 1999
    Assignee: Harris Corporation
    Inventors: Michael M. Walters, Charles E. Hawkes
  • Patent number: 5821740
    Abstract: A DC-to-DC converter includes a pulse width modulation circuit for modulating a switch to produce current pulses having at least a minimum pulse width to thereby control an output voltage to the load. The converter also includes a current limit determining circuit for determining when a desired peak current is no longer sufficient to maintain a desired output voltage thereby defining a current limit condition. In addition, the pulse width modulating circuit, when operating at the minimum pulse width, thereby defines a minimum pulse width condition. Accordingly, the converter preferably further includes an over-current determining circuit for determining an over-current condition responsive to the minimum pulse width condition being reached during a current limit condition. The converter may turn off the switch responsive to an over-current condition. A blanking signal may be used to clamp a comparator and established a minimum pulse width.
    Type: Grant
    Filed: February 14, 1997
    Date of Patent: October 13, 1998
    Assignee: Harris Corporation
    Inventors: Robert G. Hodgins, Charles E. Hawkes, Michael M. Walters
  • Patent number: 5808883
    Abstract: A DC-to-DC converter includes a charge pump, connected to a switch drive and to an input voltage, for selectively boosting the supply voltage to the switch drive; and a charge pump controller cooperating with the charge pump for controlling the supply voltage to the switch drive. The charge pump preferably includes a plurality of transistors connected in series with the supply voltage, and at least one capacitor connected to the transistors. The charge pump controller passes through the input voltage to the supply voltage based upon the input voltage being above a first voltage; boosts the supply voltage to a substantially constant value based upon the input voltage being less than the first voltage and greater than or equal to a second voltage wherein the second voltage is less than the first voltage; and boosts the supply voltage by a multiple of the input voltage based upon the input voltage being less than the second voltage. Method aspects of the invention are also disclosed.
    Type: Grant
    Filed: February 14, 1997
    Date of Patent: September 15, 1998
    Assignee: Harris Corporation
    Inventor: Charles E. Hawkes
  • Patent number: RE38780
    Abstract: A DC/DC converter has an output voltage and sources an output current to a load. The DC/DC converter includes an error amplifier with a reference input and a summing input. The reference input is electrically connected to a reference voltage. The summing input is electrically connected to the output voltage and the output current. The summing input is configured for adding together the output voltage and the output current. The error amplifier issues an error signal and adjusts the error signal dependent at least in part upon the output voltage and the output current. A comparator receives the error signal. The comparator has a ramp input electrically connected to a voltage ramp signal. The comparator issues an output signal that is based at least in part upon said error input. A power switch has an on condition and an off condition, and supplies dc current to the load when in the on condition. The power switch has a control input electrically connected to the comparator output signal.
    Type: Grant
    Filed: February 26, 2003
    Date of Patent: August 23, 2005
    Assignee: Intersil Americas Inc.
    Inventors: Charles E. Hawkes, Michael M. Walters, Robert H. Isham
  • Patent number: RE38846
    Abstract: A multi-phase DC/DC converter having an output voltage and including a plurality of converter channels. Each converter channel includes a converter channel input and a converter channel output. Each converter channel is configured for generating a converter channel current and for adjusting said converter channel current in response to a control signal electrically connected to each converter channel input. A control circuit generates an error signal representative of a comparison of the converter output voltage to a reference voltage. The control circuit includes a plurality of control circuit channels, each of which correspond to a converter channel. Each control circuit channel generates a channel current signal representative of a corresponding converter channel current, and generates a differential channel current signal representative of a comparison of the channel current signal to an average current signal.
    Type: Grant
    Filed: February 26, 2003
    Date of Patent: October 25, 2005
    Assignee: Intersil Communications, Inc.
    Inventors: Michael M. Walters, Charles E. Hawkes, Robert H. Isham
  • Patent number: RE38906
    Abstract: A DC/DC converter has an output voltage and sources an output current to a load. The DC/DC converter includes an error amplifier with a reference input and a summing input. The reference input is electrically connected to a reference voltage. The summing input is electrically connected to the output voltage and the output current. The summing input is configured for adding together the output voltage and the output current. The error amplifier issues an error signal and adjusts the error signal dependent at least in part upon the output voltage and the output current. A comparator receives the error signal. The comparator has a ramp input electrically connected to a voltage ramp signal. The comparator issues an output signal that is based at least in part upon said error input. A power switch has an on condition and an off condition, and supplies dc current to the load when in the on condition. The power switch has a control input electrically connected to the comparator output signal.
    Type: Grant
    Filed: January 11, 2002
    Date of Patent: December 6, 2005
    Assignee: Intersil Americas, Inc.
    Inventors: Charles E. Hawkes, Michael M. Walters, Robert H. Isham
  • Patent number: RE38940
    Abstract: A DC to DC buck pulse width modulator converter circuit includes an input, a high side output and a low side output. A high side switch is electrically connected between a common output node and a voltage supply, and controls a flow of current therethrough dependent upon the high side output. A low side switch is electrically connected between the common output node and ground, and controls a flow of current therethrough dependent upon the low side output. A virtual ground amplifier includes a second input electrically connected to ground. A current feedback resistor is electrically connected intermediate the common output node and a first input of the virtual ground amplifier. A variable impedance component is electrically connected to an output of the virtual ground amplifier and to the first input of the virtual ground amplifier. The impedance of the variable impedance component is varied dependent upon the output of the virtual ground amplifier.
    Type: Grant
    Filed: October 29, 2002
    Date of Patent: January 24, 2006
    Assignee: Intersil Communications, Inc.
    Inventors: Robert H. Isham, Charles E. Hawkes, Michael M. Walters
  • Patent number: RE38454
    Abstract: A multi-phase DC/DC converter having an output voltage and including a plurality of converter channels. Each converter channel includes a converter channel input and a converter channel output. Each converter channel is configured for generating a converter channel current and for adjusting said converter channel current in response to a control signal electrically connected to each converter channel input. A control circuit generates an error signal representative of a comparison of the converter output voltage to a reference voltage. The control circuit includes a plurality of control circuit channels, each of which correspond to a converter channel. Each control circuit channel generates a channel current signal representative of a corresponding converter channel current, and generates a differential channel current signal representative of a comparison of the channel current signal to an average current signal.
    Type: Grant
    Filed: January 11, 2002
    Date of Patent: March 9, 2004
    Assignee: Intersil Communications, Inc.
    Inventors: Michael M. Walters, Charles E. Hawkes, Robert H. Isham
  • Patent number: RE38487
    Abstract: A DC to DC buck pulse width modulator converter circuit includes an input, a high side output and a low side output. A high side switch is electrically connected between a common output node and a voltage supply, and controls a flow of current therethrough dependent upon the high side output. A low side switch is electrically connected between the common output node and ground, and controls a flow of current therethrough dependent upon the low side output. A virtual ground amplifier includes a second input electrically connected to ground. A current feedback resistor is electrically connected intermediate the common output node and a first input of the virtual ground amplifier. A variable impedance component is electrically connected to an output of the virtual ground amplifier and to the first input of the virtual ground amplifier. The impedance of the variable impedance component is varied dependent upon the output of the virtual ground amplifier.
    Type: Grant
    Filed: January 11, 2002
    Date of Patent: April 6, 2004
    Assignee: Intersil Communications, Inc.
    Inventors: Robert H. Isham, Charles E. Hawkes, Michael M. Walters
  • Patent number: RE40593
    Abstract: A multi-phase DC/DC converter having an output voltage and including a plurality of converter channels. Each converter channel includes a converter channel input and a converter channel output. Each converter channel is configured for generating a converter channel current and for adjusting said converter channel current in response to a control signal electrically connected to each converter channel input. A control circuit generates an error signal representative of a comparison of the converter output voltage to a reference voltage. The control circuit includes a plurality of control circuit channels, each of which correspond to a converter channel. Each control circuit channel generates a channel current signal representative of a corresponding converter channel current, and generates a differential channel current signal representative of a comparison of the channel current signal to an average current signal.
    Type: Grant
    Filed: October 24, 2005
    Date of Patent: December 2, 2008
    Assignee: Intersil Americas Inc.
    Inventors: Michael M. Walters, Charles E. Hawkes, Robert H. Isham
  • Patent number: RE42063
    Abstract: A multi-phase DC/DC converter having an output voltage and including a plurality of converter channels. Each converter channel includes a converter channel input and a converter channel output. Each converter channel is configured for generating a converter channel current and for adjusting said converter channel current in response to a control signal electrically connected to each converter channel input. A control circuit generates an error signal representative of a comparison of the converter output voltage to a reference voltage. The control circuit includes a plurality of control circuit channels, each of which correspond to a converter channel. Each control circuit channel generates a channel current signal representative of a corresponding converter channel current, and generates a differential channel current signal representative of a comparison of the channel current signal to an average current signal.
    Type: Grant
    Filed: December 1, 2008
    Date of Patent: January 25, 2011
    Assignee: Intersil Americas Inc.
    Inventors: Michael M. Walters, Charles E. Hawkes, Robert H. Isham
  • Patent number: RE42532
    Abstract: A DC to DC buck pulse width modulator converter circuit includes an input, a high side output and a low side output. A high side switch is electrically connected between a common output node and a voltage supply, and controls a flow of current therethrough dependent upon the high side output. A low side switch is electrically connected between the common output node and ground, and controls a flow of current therethrough dependent upon the low side output. A virtual ground amplifier includes a second input electrically connected to ground. A current feedback resistor is electrically connected intermediate the common output node and a first input of the virtual ground amplifier. A variable impedance component is electrically connected to an output of the virtual ground amplifier and to the first input of the virtual ground amplifier. The impedance of the variable impedance component is varied dependent upon the output of the virtual ground amplifier.
    Type: Grant
    Filed: January 23, 2006
    Date of Patent: July 12, 2011
    Assignee: Intersil Americas Inc.
    Inventors: Robert H. Isham, Charles E. Hawkes, Michael M. Walters
  • Patent number: RE42897
    Abstract: A DC/DC converter has an output voltage and sources an output current to a load. The DC/DC converter includes an error amplifier with a reference input and a summing input. The reference input is electrically connected to a reference voltage. The summing input is electrically connected to the output voltage and the output current. The summing input is configured for adding together the output voltage and the output current. The error amplifier issues an error signal and adjusts the error signal dependent at least in part upon the output voltage and the output current. A comparator receives the error signal. The comparator has a ramp input electrically connected to a voltage ramp signal. The comparator issues an output signal that is based at least in part upon said error input. A power switch has an on condition and an off condition, and supplies dc current to the load when in the on condition. The power switch has a control input electrically connected to the comparator output signal.
    Type: Grant
    Filed: December 5, 2005
    Date of Patent: November 8, 2011
    Assignee: Intersil Americas Inc.
    Inventors: Charles E. Hawkes, Michael M. Walters, Robert H. Isham
  • Patent number: RE44910
    Abstract: A DC/DC converter has an output voltage and sources an output current to a load. The DC/DC converter includes an error amplifier with a reference input and a summing input. The reference input is electrically connected to a reference voltage. The summing input is electrically connected to the output voltage and the output current. The summing input is configured for adding together the output voltage and the output current. The error amplifier issues an error signal and adjusts the error signal dependent at least in part upon the output voltage and the output current. A comparator receives the error signal. The comparator has a ramp input electrically connected to a voltage ramp signal. The comparator issues an output signal that is based at least in part upon said error input. A power switch has an on condition and an off condition, and supplies dc current to the load when in the on condition. The power switch has a control input electrically connected to the comparator output signal.
    Type: Grant
    Filed: September 30, 2011
    Date of Patent: May 27, 2014
    Assignee: Intersil Americas Inc.
    Inventors: Charles E. Hawkes, Michael M. Walters, Robert H. Isham