Patents Assigned to O2Micro International
  • Patent number: 7345431
    Abstract: A DC/AC converter circuit structure for driving a plurality of cold cathode fluorescent lamps is described. A common-mode choke is used between the cold cathode fluorescent lamps. The common-mode choke balances the currents respectively flowing through the cold cathode fluorescent lamps.
    Type: Grant
    Filed: March 13, 2007
    Date of Patent: March 18, 2008
    Assignee: O2Micro International Limited
    Inventor: Sheng Tai Lee
  • Patent number: 7343498
    Abstract: A method according to one embodiment includes receiving at least one ExpressCard module power management signal and controlling the passing of at least one ExpressCard power management signal to a host computer system, based on, at least in part, at least one signal indicative of a power state of the host computer system. Of course, many alternatives, variations, and modifications are possible without departing from this embodiment.
    Type: Grant
    Filed: December 10, 2004
    Date of Patent: March 11, 2008
    Assignee: O2Micro International Limited
    Inventor: Neil Morrow
  • Patent number: 7343484
    Abstract: A personal computer (PC) adapted to function as a personal digital assistant (PDA) includes: a central processing unit (CPU) responsive to a control signal to load a first operating system or a second operating system, wherein the first operating system is run by the PC in a first PC mode and the second operating system is run by the PC in a second PDA mode. A method of operating a personal computer (PC) in either a PC mode or a PDA mode is also provided that includes: initiating a control signal; and loading a first or second operating system based on the control signal, wherein the first operating system operates the PC is the first PC mode and the second operating system operates the PC is the second PDA mode.
    Type: Grant
    Filed: March 28, 2002
    Date of Patent: March 11, 2008
    Assignee: O2Micro International Limited
    Inventors: Sterling Du, Bruce Denning, James Lam
  • Patent number: 7331001
    Abstract: The present invention provides a test card for multiple functions testing. The test card includes a host of media devices, all of which reside on a single printed circuit board; and a selection device which selects each one of the host of media devices for testing. The test card can test all SD, MMC, MS (Pro), SMC devices and functions in one time in a bench without inserting and removing the media devices, thus accelerates the production line test speed.
    Type: Grant
    Filed: April 6, 2004
    Date of Patent: February 12, 2008
    Assignee: O2Micro International Limited
    Inventors: Han-Jung Kao, Shih-Chun Chen, Chun-Hsi Lin, Chih-Lang Lin, ShyhShin Lee
  • Patent number: 7324037
    Abstract: An analog to digital converter (ADC) with interference rejection capability and method thereof are disclosed. The ADC includes a threshold generator, a comparator circuit, a counter and an integrator. By comparing a signal with positive and negative threshold signals from the threshold generator, the comparator circuit converts the signal from analog to digital based on the result of the comparison. The counter counts a percentage of the digital signal and generates a bit signal based on the counted percentage. In response to the bit signal, the integrator supplies a control signal to the threshold generator to regulate the positive and negative threshold signals so as to maintain the counted percentage at a predetermined percentage threshold.
    Type: Grant
    Filed: July 14, 2006
    Date of Patent: January 29, 2008
    Assignee: O2Micro International Ltd.
    Inventors: Seeteck Tan, Wenhuan Chen
  • Patent number: 7319346
    Abstract: A programmable after-package, on-chip reference voltage trim circuit for an integrated circuit having a plurality of programmable trim cells generating a programmed sequence. A converter is provided to convert the bit sequence into a trim current. The trim current is added to an initial value of a reference voltage to be trimmed, as generated by the integrated circuit. Once the correct value of the trim current is determined, isolation circuitry is programmed to isolate the trim circuitry from the remainder of the IC, thereby freeing the logic and package pins associated with the IC for use by users of the IC. The preferred trim circuitry includes fuses which are blown in accordance with a bit value supplied to the trim cell to permanently fix a trim current value, once a best fit value is determined.
    Type: Grant
    Filed: January 23, 2004
    Date of Patent: January 15, 2008
    Assignee: O2Micro International Limited
    Inventors: You-Yuh Shyr, Sorin Laurentiu Negru
  • Patent number: 7309021
    Abstract: A dual mode smart card controller is provided. In one embodiment, a USB and ISO7816 smart card controller is provided that determines the type of card that is inserted into a slot. If the smart card is a USB smart card, the controller is adapted to pass control of the smart card to an external PC host USB hub circuit. If the smart card is an ISO7816 card, then control is handled by the dual mode controller. In another embodiment, the controller includes an embedded USB hub circuit to permit the controller to directly control both USB and ISO7816 smart cards. Exemplary control sequencing includes monitoring a C4 signal line for a preselected time period, or generating an enable signal if a USB smart card is detected.
    Type: Grant
    Filed: December 18, 2006
    Date of Patent: December 18, 2007
    Assignee: O2Micro International Limited
    Inventors: Neil Morrow, Hyang-Kyun Oh, Ching-Yung Han
  • 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
  • Patent number: 7292946
    Abstract: A controller includes a plurality of readers for reading an associated plurality of expansion cards and for controlling operation of such expansion cards, wherein at least one of the plurality of readers is a flash media reader. A method for controlling the operation of at least one expansion card with an integrated controller having a plurality of readers includes detecting the presence of at least one expansion card, and enabling a selected reader of the integrated controller associated with at least one expansion card. Another method of writing data to read only memory in an integrated controller includes unlocking the read only memory, writing information into the read only memory, and locking the read only memory to prevent otherwise unintentional or unauthorized writing to the read only memory is also provided.
    Type: Grant
    Filed: April 6, 2004
    Date of Patent: November 6, 2007
    Assignee: O2Micro International Limited
    Inventors: Yishao Max Huang, Sterling D. Du
  • 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
  • Patent number: 7268520
    Abstract: A sense amplifier adapted to amplify a voltage signal representative of a charging current provided to a rechargeable battery. The sense amplifier may include a p-type input sense amplifier and an n-type input sense amplifier, The p-type input sense amplifier may be enabled and the n-type input sense amplifier may be disabled if a battery voltage level of the rechargeable battery is less than an under voltage threshold level. The p-type input sense amplifier may be disabled and the n-type input sense amplifier may be enabled if the battery voltage level is greater than or equal to the under voltage threshold level. A related method and an electronic device having a sense amplifier consistent with an embodiment are also provided.
    Type: Grant
    Filed: April 8, 2005
    Date of Patent: September 11, 2007
    Assignee: O2Micro International Limited
    Inventor: Chun Lu
  • 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: 7248240
    Abstract: The present invention provides a driving circuit with protection function for driving a set of external electrode fluorescent lamps (EEFL) . The drive circuit includes, a transformer connected to the set of EEFLs, a switching network connected to the transformer which delivers power to the transformer, a sensing circuit connected to the set of EEFLs which detects disconnection if one light source is disconnected, and a controller connected to the switching network which controls the switching network to reduce the total current supplied to the EEFLs which remain connected, if the sensing circuit detects that one EEFL is disconnected. Appropriate protection can therefore be implemented when the EEFL is disconnected on one end or both ends.
    Type: Grant
    Filed: September 5, 2006
    Date of Patent: July 24, 2007
    Assignee: O2Micro International Limited
    Inventors: Yung-Lin Lin, Da Liu
  • 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
  • Publication number: 20070152608
    Abstract: A DC/AC converter circuit structure for driving a plurality of cold cathode fluorescent lamps is described. A common-mode choke is used between the cold cathode fluorescent lamps. The common-mode choke balances the currents respectively flowing through the cold cathode fluorescent lamps.
    Type: Application
    Filed: March 13, 2007
    Publication date: July 5, 2007
    Applicant: O2MICRO INTERNATIONAL LIMITED
    Inventor: Sheng Lee
  • Patent number: 7233117
    Abstract: The present invention is an inverter controller with feed-forward compensation. The inverter controller includes an error amplifier, a high frequency oscillator (HFOSC) with feed-forward compensation, a comparator, and a driver. The error amplifier can output a signal independent on the variation of a supply voltage. The HFOSC can generate a saw-tooth signal with a constant frequency and an amplitude proportional to the supply voltage. The comparator can compare the signal with the saw-tooth signal and generate a pulse width modulation signal whose duty cycle varies with the variation of the supply voltage. The driver receives the PWM signal and provides a proper pulse width modulation signal to drive an external inverter.
    Type: Grant
    Filed: August 9, 2005
    Date of Patent: June 19, 2007
    Assignee: O2Micro International Limited
    Inventors: Zhao Wang, Ruiqing Xu
  • 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
  • Patent number: 7202634
    Abstract: A circuit for controlling a charging parameter provided to a rechargeable battery. The circuit includes a power control circuit configured to provide a power control signal representative of a power output level of a DC source, and a control signal generating circuit configured to reduce the charging parameter provided to the battery if the power output level exceeds a predetermined power threshold level. An electronic device having such a circuit and a method is also provided. The circuit may be used with a DC source that supplies power to recharge a rechargeable battery. The DC source may have a non-fixed output voltage level such as from a controllable DC source or a variable DC source.
    Type: Grant
    Filed: January 15, 2004
    Date of Patent: April 10, 2007
    Assignee: O2Micro International Limited
    Inventor: Constantin Bucur
  • Patent number: 7200017
    Abstract: A controller for controlling at least two power circuits comprises a phase-shift selector for generating a reference signal according to variable input signals, the reference signal is programmed to indicate an amount of phase-delay according to a number of CCFL power circuits connected; and a pulse generator for receiving the reference signal and generating a pulse signal CLK in response to the received reference signal, the pulse signal is coupled to the CCFL power circuits connected for initiating the operation of the CCFL power circuits. The controller is used to control energy supplying to an electrical circuit comprising multiple CCFL power circuits and is more particularly to provide phase delay to the electrical circuit. Usually, the electrical circuit is applied to display devices, such as liquid crystal display monitors, liquid crystal display computers and liquid crystal display televisions.
    Type: Grant
    Filed: January 13, 2004
    Date of Patent: April 3, 2007
    Assignee: O2Micro International Limited
    Inventor: Yung-Lin Lin
  • Patent number: 7191270
    Abstract: An integrated controller for the detection and operation of both PC Cards, smart cards and passive smart card adapter cards. In one aspect, the invention detects the presence of standard expansion cards or passive smart card adapters by utilizing the reserved detection and voltage selection signal area defined by the PC Card specification. In another aspect, the invention provides an integrated controller that includes logic to operate either a standard expansion card or a passive smart card adapter by reassigning certain PC Card signal lines to operate a standard expansion card or a passive smart card adapter, thereby eliminating the need to provide pins in addition to those defined by the PC Card specification.
    Type: Grant
    Filed: September 4, 2003
    Date of Patent: March 13, 2007
    Assignee: O2Micro International Limited
    Inventors: Hyang-Kyun Oh, Yishao Max Huang, Richard Brayden