Patents Assigned to Iwatt
  • Patent number: 7433211
    Abstract: A power converter delivers electrical power from an electrical power source to a load according to a plurality of operation modes, where at least one of the operation modes is a peak current switching mode. Under the peak current switching mode, a switch controller controls the switch in the power converter to be kept on until the current through the switch reaches a peak current value corresponding to a given phase of the input voltage signal to the power converter. The peak current values have a reference shape, which may be a trapezoidal. The power converter may have any topology, such as a flyback-type power converter or a boost-type power converter.
    Type: Grant
    Filed: June 28, 2004
    Date of Patent: October 7, 2008
    Assignee: iWatt Inc.
    Inventors: Arthur J. Collmeyer, Anatoly Shteynberg, Junjie Zheng, Paul F. King, Dickson T. Wong, Harry Rodriguez
  • Patent number: 7382308
    Abstract: A reference buffer includes a first current mirror, a second current mirror, a first source follower coupled in series to a branch of the first current mirror and receiving a first initial reference voltage and outputting a first reference voltage, a second source follower coupled in series to a branch of the second current mirror and receiving a second initial reference voltage and outputting a second reference voltage, and a resistor coupled between a first node and a second node outputting the first and second reference voltages, respectively. The first node is disposed between the first current mirror and the first source follower and the second node is disposed between the second current mirror and the second source follower. The voltage difference between the first reference voltage and the first initial reference voltage is substantially same as that between the second reference voltage and the second initial reference voltage.
    Type: Grant
    Filed: February 16, 2007
    Date of Patent: June 3, 2008
    Assignee: iWatt Inc.
    Inventors: Enzhu Liang, Xuecheng Jin
  • Publication number: 20080122422
    Abstract: A method and apparatus to implement parallel current mode control that is suitable for digital and analog implementation. A duty cycle algorithm is composed of a voltage term and a parallel current term which depends on the inductor current change between the inductor current value at the beginning of a switching cycle and the reference inductor current value at the end of that switching cycle. Parallel current mode control can be applied to all DC-DC converters, including both non-isolated and isolated topologies. It can also be applied to AC-DC converters with power factor correction.
    Type: Application
    Filed: December 5, 2007
    Publication date: May 29, 2008
    Applicant: IWATT INC.
    Inventors: Wanfeng Zhang, Yan-Fei Liu, Bin Wu
  • Publication number: 20080112193
    Abstract: A primary side sensing power control system and method for constant current control that utilizes a relationship that involves the measured reset-time from the previous cycle to determine the primary side peak current and off-time for the next cycle. This control mechanism does not need the knowledge of input voltage or magnetizing inductance. Therefore, it removes the sensitivities of input voltage and magnetizing inductance to the output current limit. Furthermore, it uses a time measurement instead of a voltage measurement for the current calculation which in many cases is easier to perform.
    Type: Application
    Filed: May 7, 2007
    Publication date: May 15, 2008
    Applicant: iWatt Inc.
    Inventors: Liang Yan, Junjie Zheng, John Kesterson, Xiaoyan Wang, Hien Bui
  • Patent number: 7336058
    Abstract: A low dropout (LDO) voltage regulator having more than one LDO modules, each LDO module having a frequency response adapted to a certain range of output frequency. The LDO voltage regulator can provide a gain over a broad range of operating frequency by combining output current from each LDO module and providing the combined current at an output of the LDO voltage regulator. The LDO voltage regulator further comprises a load monitor coupled to the LDO modules for disabling some of the LDO modules to reduce power consumption of the LDO voltage regulator.
    Type: Grant
    Filed: February 6, 2007
    Date of Patent: February 26, 2008
    Assignee: iWatt Inc.
    Inventors: Ping Lo, Xuecheng Jin
  • Patent number: 7317625
    Abstract: A method and apparatus to implement parallel current mode control that is suitable for digital and analog implementation. A duty cycle algorithm is composed of a voltage term and a parallel current term which depends on the inductor current change between the inductor current value at the beginning of a switching cycle and the reference inductor current value at the end of that switching cycle. Parallel current mode control can be applied to all DC-DC converters, including both non-isolated and isolated topologies. It can also be applied to AC-DC converters with power factor correction.
    Type: Grant
    Filed: June 4, 2004
    Date of Patent: January 8, 2008
    Assignee: iWatt Inc.
    Inventors: Wanfeng Zhang, Yan-Fei Liu, Bin Wu
  • Patent number: 7161816
    Abstract: A power converter delivers electrical power from an electrical power source to a load according to a plurality of operation modes corresponding to different levels of input voltage or output current. The power converter comprises a power stage for delivering the electrical power from the power source to the load, a switch in the power stage that electrically couples or decouples the load to the power source, and a switch controller coupled to the switch for controlling the on-times and off-times of the switch according to the plurality of operation modes. Each of the operation modes correspond to associated ranges of at least one of an input voltage to the power converter and an output current from the power converter, where the associated ranges are different for each of the operation modes.
    Type: Grant
    Filed: August 19, 2005
    Date of Patent: January 9, 2007
    Assignee: iWatt Inc.
    Inventors: Anatoly Shteynberg, Junjie Zheng, Harry Rodriguez, Mark D. Telefus, Dongsheng Zhou, Arthur J. Collmeyer
  • Patent number: 7024649
    Abstract: A tool is described to aid in the design and verification of multi-input, multi-output power supply systems. The designer describes the system requirements and constraints to the tool, which allows an iterative exploration of various alternative designs that satisfy the requirements and constraints. Alternative designs may comprise different power supply topologies, multiple controllers or multi-controllers, or configurable controllers that implement the power supply system. The tool generates a design for a power supply system that is reconfigurable to allow for performance optimization. The power supply system is configurable automatically according to a digital control signal. The digital control signal comprises configuration data which establishes the structure of the power supply system, and which determines the output power conditions of the power source.
    Type: Grant
    Filed: February 14, 2003
    Date of Patent: April 4, 2006
    Assignee: IWATT
    Inventors: Arthur Collmeyer, Thomas Szepesi, Dickson Wong, Allen Samuels
  • Patent number: 6990000
    Abstract: An AC-to-DC power converter controller reconstructs the output voltage of the power converter without a sample-and-hold circuit or an opto-coupler. The controller includes an accumulation module for accumulating a difference value obtained by subtracting a first representation of an output voltage of the power converter corresponding to a first sampling timing from the output voltage value sampled at a second sampling timing subsequent to the first sampling timing to obtain a second representation of the output voltage of the power converter corresponding to the second sampling timing. The accumulation module may set the second representation of the output voltage to a predetermined maximum value if the output voltage value sampled at the second sampling timing exceeds the predetermined maximum value, or to a predetermined minimum value if the output voltage value sampled at the second sampling timing is less than the predetermined minimum value.
    Type: Grant
    Filed: September 17, 2004
    Date of Patent: January 24, 2006
    Assignee: iWatt Inc.
    Inventors: Harry Rodriguez, Anatoly Shteynberg, Mark D. Telefus, Mark D. Eason
  • Patent number: 6972969
    Abstract: A primary side sensing power control system and method that controls the current limit such that it is maintained within a small range for any acceptable input voltages and causes the output voltage of a PWM controller to drop as the output load increases when the current limit is reached.
    Type: Grant
    Filed: August 19, 2004
    Date of Patent: December 6, 2005
    Assignee: iWatt, Inc.
    Inventors: Anatoly Shteynberg, Junjie Zheng, Harry Rodriguez, Mark D. Telefus, Dongsheng Zhou
  • Patent number: 6956750
    Abstract: A power converter comprises an event detection module detecting various events of the power converter in real time at the switching frequency of a switch in the power converter according to predetermined criteria. A pulse generator generates control signals for controlling the on-times and off-times of the switch based on the various detected events. The events detected by the event detection module include a detection of a “knee” in the reflected secondary voltage on the auxiliary windings of the transformer in a primary side sensing flyback power converter, and detection of a digital error quantifying the difference between the reference voltage and the reflected secondary voltage on the auxiliary windings of the transformer in time domain.
    Type: Grant
    Filed: December 12, 2003
    Date of Patent: October 18, 2005
    Assignee: iWatt Inc.
    Inventors: Mark D. Eason, Harry Rodriguez, Mark R. Muegge
  • Patent number: 6944034
    Abstract: A power converter delivers electrical power from an electrical power source to a load according to a plurality of operation modes corresponding to different levels of input voltage or output current. The power converter comprises a power stage for delivering the electrical power from the power source to the load, a switch in the power stage that electrically couples or decouples the load to the power source, and a switch controller coupled to the switch for controlling the on-times and off-times of the switch according to the plurality of operation modes. Each of the operation modes correspond to associated ranges of at least one of an input voltage to the power converter and an output current from the power converter, where the associated ranges are different for each of the operation modes.
    Type: Grant
    Filed: June 30, 2003
    Date of Patent: September 13, 2005
    Assignee: iWatt Inc.
    Inventors: Anatoly Shteynberg, Junjie Zheng, Harry Rodriguez, Mark D. Telefus, Dongsheng Zhou, Arthur J. Collmeyer
  • Patent number: 6900995
    Abstract: A method of regulating voltage at an output of a switching power converter includes sensing an output voltage feedback signal; comparing the sensed feedback signal to a reference at a determined time during a cycling of the switch; and regulating the output voltage by either enabling or inhibiting cycling of a switch by a cycle of a drive signal produced by pulse generation circuitry in response to an output of the comparison.
    Type: Grant
    Filed: November 27, 2002
    Date of Patent: May 31, 2005
    Assignee: iWatt, Inc.
    Inventors: Mark R. Muegge, Mark Eason, Mark D. Telefus
  • Patent number: 6894911
    Abstract: A method of regulating voltage at an output of a switching power converter, the converter comprising a switch and pulse generation circuitry, the pulse generation circuitry producing one or more drive signals for cycling the switch ON and OFF, wherein if the switch is cycled ON and OFF according to a cycle of a drive signal, power is transferred from a source to a load. The method includes sensing an output voltage feedback signal, comparing the sensed feedback signal to a reference at a determined time during a cycling of the switch, and regulating an output voltage at the load by controlling whether a cycle of one of the drive signals cycles the switch in response to the comparison.
    Type: Grant
    Filed: November 27, 2002
    Date of Patent: May 17, 2005
    Assignee: iWatt, Inc.
    Inventors: Mark D. Telefus, Mark R. Muegge, Charles R. Geber, Dickson T. Wong
  • Patent number: 6882552
    Abstract: A power converter for delivering power from a source to a load includes a switch, pulse generation circuitry producing one or more drive signals for cycling the switch ON and OFF, wherein if the switch is cycled ON and OFF according to a cycle of a drive signal, power is transferred from the source to the load, a comparator for comparing a feedback signal approximating an output voltage at the load to a reference, and a controller coupled to the pulse generation circuitry for controlling which, if any, cycle of a drive signal cycles the switch in response to an output of the comparator.
    Type: Grant
    Filed: November 27, 2002
    Date of Patent: April 19, 2005
    Assignee: iWatt, Inc.
    Inventors: Mark D. Telefus, Mark R. Muegge, Charles R. Geber, Dickson T. Wong
  • Patent number: 6862198
    Abstract: Switching power converters for regulating voltage at an output of a load include digital control circuitry for sensing an output voltage feedback signal, comparing the sensed feedback signal to a reference at a determined time during a cycling of the switch; and regulating the output voltage by either enabling or inhibiting cycling of a switch by a cycle of a drive signal produced by pulse generation circuitry in response to the comparison.
    Type: Grant
    Filed: November 27, 2002
    Date of Patent: March 1, 2005
    Assignee: iWatt, Inc.
    Inventors: Mark R. Muegge, Mark Eason, Mark D. Telefus
  • Publication number: 20040172603
    Abstract: A tool is described to aid in the design and verification of multi-input, multi-output power supply systems. The designer describes the system requirements and constraints to the tool, which allows an iterative exploration of various alternative designs that satisfy the requirements and constraints. Alternative designs may comprise different power supply topologies, multiple controllers or multi-controllers, or configurable controllers that implement the power supply system. The tool generates a design for a power supply system that is reconfigurable to allow for performance optimization. The power supply system is configurable automatically according to a digital control signal. The digital control signal comprises configuration data which establishes the structure of the power supply system, and which determines the output power conditions of the power source.
    Type: Application
    Filed: February 14, 2003
    Publication date: September 2, 2004
    Applicant: Iwatt
    Inventors: Arthur Collmeyer, Thomas Szepesi, Wong Dickson, Allen Samuels
  • Patent number: 6765774
    Abstract: A high-impedance-insertion system suppresses load-produced electromagnetic noise from interfering into a power source by coupling the load to the power source through a switch. If the power source is an AC power source, the switch couples to the power source through a storage element and a rectifier, such that the switch is OFF (in the high impedance state) when the rectifier is reversed biased (or in a low impedance state). If the power source is a DC power source, the switch couples to the power source through a storage element and a second switch, such that the switch is OFF (in the high impedance state) when the second switch is ON (in the low impedance state).
    Type: Grant
    Filed: May 31, 2002
    Date of Patent: July 20, 2004
    Assignee: iWatt, Inc.
    Inventors: Mark D. Telefus, Anatoly Shteynberg
  • Publication number: 20040052095
    Abstract: A method of regulating voltage at an output of a switching power converter includes sensing an output voltage feedback signal; comparing the sensed feedback signal to a reference at a determined time during a cycling of the switch; and regulating the output voltage by either enabling or inhibiting cycling of a switch by a cycle of a drive signal produced by pulse generation circuitry in response to an output of the comparison.
    Type: Application
    Filed: November 27, 2002
    Publication date: March 18, 2004
    Applicant: IWATT, INC
    Inventors: Mark R. Muegge, Mark Eason, Mark D. Telefus
  • Patent number: 6707285
    Abstract: An AC to DC power converter, comprising an input, an output, a plurality of pass elements connected in parallel between the input and output, and a controller for switching ON a subset of the plurality of pass elements. The controller sets an ON time for at least one pass element in the subset based on a load at the output and a phase angle of an input voltage at the input. The input voltage may comprise a single or multi-phase signal. The number of pass elements in the subset is based on the load. In one embodiment, each pass element comprising a pair of series-connected field effect transistors coupled source to source and operated in fully enhanced mode.
    Type: Grant
    Filed: January 10, 2002
    Date of Patent: March 16, 2004
    Assignee: Iwatt
    Inventors: Mark D. Telefus, Dickson T. Wong