Patents by Inventor Laszlo Lipcsei

Laszlo Lipcsei 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).

  • Publication number: 20080094858
    Abstract: A power converter includes a transformer having a primary winding and a secondary winding, and a plurality of switches coupled to the primary and secondary winding, the plurality of switches responsive to at least one control signal to short both the primary and secondary winding during a first reset time interval. An electronic device including such a power converter and related methods are also provided. A power converter having a plurality of DC to DC converters coupled in parallel is also provided.
    Type: Application
    Filed: December 4, 2007
    Publication date: April 24, 2008
    Applicant: O2MICRO INTERNATIONAL LIMITED
    Inventors: Laszlo Lipcsei, Catalin Popovici
  • Publication number: 20080089098
    Abstract: A controller for providing out of phase drive signals to a power converter having at least a first power unit and second power unit. The controller may comprise input circuitry adapted to receive a first signal from a first path and a second signal from a second path and provide an output signal in response to a difference between the first and second signals. The first signal may be representative of a current level of the first power unit during a first time interval and the first signal representative of a current level of the second power unit during a second time interval. The controller may further comprise output circuitry responsive to the output signal from the input circuitry to provide the out of phase drive signals to the first and second power unit.
    Type: Application
    Filed: December 30, 2004
    Publication date: April 17, 2008
    Inventors: Laszlo Lipcsei, Catalin Popovici
  • Publication number: 20080079403
    Abstract: A switching resistance linear regulator. The regulator comprises an output terminal producing a regulated output voltage, a first comparator, a second comparator, a first sourcing circuit coupled to the output terminal, and a first sinking circuit coupled to the output terminal. The first comparator compares a feedback signal representative of the output voltage and a first sourcing reference signal that is less than a reference signal. The second comparator compares the feedback signal and a first sinking reference signal that is greater than the reference signal. The first sourcing circuit is configured to be responsive to the first comparator by sourcing a first current to the output terminal. The first sinking circuit is configured to be responsive to the second comparator by sinking a second current from the output terminal.
    Type: Application
    Filed: October 2, 2006
    Publication date: April 3, 2008
    Inventors: Laszlo Lipcsei, Serban Popescu, ChengHwa Teh
  • Publication number: 20080049478
    Abstract: A DC-to-DC converter with improved transient response, accuracy and stability is disclosed. The DC-to-DC converter includes a comparator, a driver, at least one switch and a stability circuit. The stability circuit receives a voltage signal based upon sensing one of the at least one switch. The configuration with elimination a current sensing resistor can create a simpler solution for the DC-to-DC converter.
    Type: Application
    Filed: June 11, 2007
    Publication date: February 28, 2008
    Inventors: Footshen Wong, Laszlo Lipcsei, Sheng Huang
  • Publication number: 20070285066
    Abstract: A buck topology that provides voltage step up and polarity change is disclosed. In one embodiment a converter includes an input for receiving an input voltage, a switching circuit coupled to the input for receiving a first driving signal, a floating voltage source coupled to the switching circuit for producing an offset voltage, and an output coupled to the floating voltage source for generating an output voltage. The output voltage exhibits a voltage level that is directly proportional to a duty cycle of the first driving signal.
    Type: Application
    Filed: March 29, 2007
    Publication date: December 13, 2007
    Inventors: Laszlo Lipcsei, Serban Popescu, Sorin Hornet
  • Patent number: 7304866
    Abstract: A power converter includes a transformer having a primary winding and a secondary winding, and a plurality of switches coupled to the primary and secondary winding, the plurality of switches responsive to at least one control signal to short both the primary and secondary winding during a first reset time interval. An electronic device including such a power converter and related methods are also provided. A power converter having a plurality of DC to DC converters coupled in parallel is also provided.
    Type: Grant
    Filed: February 10, 2004
    Date of Patent: December 4, 2007
    Assignee: O2Micro International Limited
    Inventors: Laszlo Lipcsei, Catalin Popovici
  • Publication number: 20070253230
    Abstract: A DC to DC converter includes a comparator, a driver, and a pair of switches. The comparator compares the output voltage with a reference voltage signal and generates a PWM signal. The driver drives the switches so as to force the output voltage to follow the reference signal. In a multiphase architecture, two or more such converter circuits are incorporated to minimize the output voltage ripple and further reduce the recovery time. In a two-phase architecture, two reference signals are phase-shifted by 180 degrees. In an N-phase architecture, the reference signals are phase-shifted by 360/N degrees.
    Type: Application
    Filed: July 10, 2007
    Publication date: November 1, 2007
    Applicant: O2MICRO INTERNATIONAL LIMITED
    Inventor: Laszlo Lipcsei
  • Publication number: 20070222507
    Abstract: A low distortion class-D amplifier. The amplifier comprises a power supply terminal for receiving power, an amplification stage, and an output stage. The amplification stage receives an input signal and generates a ramp signal. Further more, the amplification stage generates a pulse width modulation signal based on the ramp signal and a hysteretic signal. The output stage coupled to the power supply terminal receives the pulse width modulation signal and generates an output. Advantageously, the ramp signal and the hysteretic signal are positioned at a voltage level that is half the voltage level of said power supply and that varies proportionally with said power supply.
    Type: Application
    Filed: December 20, 2006
    Publication date: September 27, 2007
    Inventor: Laszlo Lipcsei
  • Publication number: 20070176587
    Abstract: A DC to DC converter to convert an input voltage to an output voltage. The DC to DC converter may include a pair of switches including a high side switch and a low side switch, an inductor coupled to the pair of switches; and a controller. The controller may be configured to estimate a zero crossing of an inductor current through the inductor without directly measuring said inductor current. An associated method is also provided.
    Type: Application
    Filed: April 10, 2007
    Publication date: August 2, 2007
    Applicant: O2MICRO INTERNATIONAL LIMITED
    Inventors: Laszlo Lipcsei, Serban-Mihai Popescu
  • Patent number: 7242598
    Abstract: A DC to DC converter includes a comparator, a driver, and a pair of switches. The comparator compares the output voltage with a reference voltage signal and generates a PWM signal. The driver drives the switches so as to force the output voltage to follow the reference signal. In a multiphase architecture, two or more such converter circuits are incorporated to minimize the output voltage ripple and further reduce the recovery time. In a two-phase architecture, two reference signals are phase-shifted by 180 degrees. In an N-phase architecture, the reference signals are phase-shifted by 360/N degrees.
    Type: Grant
    Filed: April 18, 2006
    Date of Patent: July 10, 2007
    Assignee: O2Micro International Limited
    Inventor: Laszlo Lipcsei
  • Patent number: 7202650
    Abstract: A DC to DC converter to convert an input voltage to an output voltage. The DC to DC converter may include a pair of switches including a high side switch and a low side switch, an inductor coupled to the pair of switches; and a controller. The controller may be configured to estimate a zero crossing of an inductor current through the inductor without directly measuring said inductor current. An associated method is also provided.
    Type: Grant
    Filed: November 9, 2005
    Date of Patent: April 10, 2007
    Assignee: O2Micro International Limited
    Inventors: Laszlo Lipcsei, Serban-Mihai Popescu
  • Publication number: 20070069699
    Abstract: A DC/DC converter for converting an input voltage to an output voltage comprises a switch, an inductor, two voltage dividers, a capacitor, and a controller. The switch coupled to the input voltage. The inductor having a parasitic direct current resistance is used for coupling the switch to an output node of the DC/DC converter so as to generate the output voltage at the output node. The first voltage divider is coupled to the output node for generating a divided voltage of the output voltage. The second voltage divider is coupled to the switch and ground. The capacitor coupled to the first voltage divider and the second divider to measure the current through the inductor by sensing a voltage across the capacitor. The controller coupled to the first switch for enabling and disenabling it so as to discontinuously providing power from the input voltage to the inductor.
    Type: Application
    Filed: September 21, 2006
    Publication date: March 29, 2007
    Inventor: Laszlo Lipcsei
  • Patent number: 7196499
    Abstract: A DC/DC converter for converting an input voltage to an output voltage comprises a switch, an inductor, two voltage dividers, a capacitor, and a controller. The switch coupled to the input voltage. The inductor having a parasitic direct current resistance is used for coupling the switch to an output node of the DC/DC converter so as to generate the output voltage at the output node. The first voltage divider is coupled to the output node for generating a divided voltage of the output voltage. The second voltage divider is coupled to the switch and ground. The capacitor coupled to the first voltage divider and the second divider to measure the current through the inductor by sensing a voltage across the capacitor. The controller coupled to the first switch for enabling and disenabling it so as to discontinuously providing power from the input voltage to the inductor.
    Type: Grant
    Filed: September 21, 2006
    Date of Patent: March 27, 2007
    Assignee: 02Micro, Inc.
    Inventor: Laszlo Lipcsei
  • Publication number: 20070040538
    Abstract: The DC/DC converter according to one embodiment includes a switch, an inductor, a capacitor, a resistor, and a voltage divider. The switch is coupled to the input voltage. The inductor is used for coupling the first switch to an output node of the DC/DC converter so as to generate the output voltage at the output node. The capacitor is coupled to the output voltage. The resistor is coupled to the capacitor in series, and is coupled to ground. The voltage divider is coupled across the capacitor so as to reduce the zero frequency of the DC/DC converter.
    Type: Application
    Filed: August 11, 2006
    Publication date: February 22, 2007
    Inventors: Laszlo Lipcsei, Sorin Hornet
  • Publication number: 20060284608
    Abstract: A method includes starting a time count of a time interval at a start of a state change of a switch of a DC to DC converter; monitoring if the switch is in a skip mode; and disabling the skip mode in response to an expiration of the time interval so that the switch changes states at a frequency rate greater than an audible frequency for humans.
    Type: Application
    Filed: August 29, 2006
    Publication date: December 21, 2006
    Applicant: O2MICRO INTERNATIONAL LIMITED
    Inventors: Laszlo Lipcsei, Serban-Mihai Popescu
  • Publication number: 20060203526
    Abstract: A DC to DC converter includes a comparator, a driver, and a pair of switches. The comparator compares the output voltage with a reference voltage signal and generates a PWM signal. The driver drives the switches so as to force the output voltage to follow the reference signal. In a multiphase architecture, two or more such converter circuits are incorporated to minimize the output voltage ripple and further reduce the recovery time. In a two-phase architecture, two reference signals are phase-shifted by 180 degrees. In an N-phase architecture, the reference signals are phase-shifted by 360/N degrees.
    Type: Application
    Filed: April 18, 2006
    Publication date: September 14, 2006
    Applicant: O2Micro International Limited
    Inventor: Laszlo Lipcsei
  • Patent number: 7098642
    Abstract: A method includes starting a time count of a time interval at a start of a state change of a switch of a DC to DC converter; monitoring if the switch is in a skip mode; and disabling the skip mode in response to an expiration of the time interval so that the switch changes states at a frequency rate greater than an audible frequency for humans.
    Type: Grant
    Filed: January 18, 2005
    Date of Patent: August 29, 2006
    Assignee: O2Micro International Limited
    Inventors: Laszlo Lipcsei, Serban-Mihai Popescu
  • Publication number: 20060120122
    Abstract: A DC to DC converter having improved transient response, accuracy, and stability. The DC to DC converter includes a comparator configured to compare a reference signal with a second signal. The reference signal has a DC offset determined, at least in part, by a DC reference voltage source. The second signal is representative of an output voltage of the DC to DC converter. The comparator is further configured to provide a control signal to a driver that drives the output voltage of the DC to DC converter in response to a comparison of the reference and second signal. The DC to DC converter further includes an accuracy circuit to enhance accuracy of the DC to DC converter. The DC to DC converter may further include a stability circuit to enhance stability of the DC to DC converter.
    Type: Application
    Filed: January 30, 2006
    Publication date: June 8, 2006
    Inventor: Laszlo Lipcsei
  • Publication number: 20060120116
    Abstract: A power converter may include a transformer having a primary winding and a secondary winding. A first high side switch and a first low side switch may be coupled in series along a first path of a full bridge circuit, having a first node between the first high side switch and the first low side switch. The power converter may also comprise a second high side switch and a second low side switch coupled in series along a second path of the full bridge circuit, having a second node between the second high side switch and the second low side switch. The power converter may further comprise a first path capable of providing a first rectifier drive signal from the first node to a second rectifier switch, and a second path capable of providing a second rectifier drive signal from the second node to a first rectifier switch.
    Type: Application
    Filed: January 30, 2006
    Publication date: June 8, 2006
    Inventors: Laszlo Lipcsei, Catalin Popovici
  • Patent number: 7031174
    Abstract: A DC-to-DC converter includes a comparator, a driver, and a pair of switches. The comparator compares the output voltage with a reference voltage signal and generates a PWM signal. The driver drives the switches so as to force the output voltage to follow the reference signal. In a multiphase architecture, two or more such converter circuits are incorporated to minimize the output voltage ripple and further reduce the recovery time. In a two-phase architecture, two reference signals are phase-shifted by 180 degrees. In an N-phase architecture, the reference signals are phase-shifted by 360/N degrees.
    Type: Grant
    Filed: August 26, 2003
    Date of Patent: April 18, 2006
    Assignee: O2Micro International Limited
    Inventor: Laszlo Lipcsei