Patents Assigned to O2Micro International Limited
  • Patent number: 7847491
    Abstract: A sequential burst mode regulation system to deliver power to a plurality of loads. In the exemplary embodiments, the system of the present invention generates a plurality of phased pulse width modulated signals from a single pulse width modulated signal, where each of the phased signals regulates power to a respective load. Exemplary circuitry includes a PWM signal generator, and a phase delay array that receives a PWM signal and generates a plurality of phased PWM signals which are used to regulate power to respective loads. A frequency selector circuit can be provided that sets the frequency of the PWM signal using a fixed or variable frequency reference signal.
    Type: Grant
    Filed: January 12, 2009
    Date of Patent: December 7, 2010
    Assignee: O2Micro International Limited
    Inventors: Yung-Lin Lin, Yu-Cheng Chang, Bingwei Yao
  • Patent number: 7847783
    Abstract: A method according to one embodiment may include supplying power to an LED array having at least a first string of LEDs and a second string of LEDs coupled in parallel, each of the strings includes at least two LEDs. The method of this embodiment may also include comparing a first feedback signal from the first string of LEDs and a second feedback signal from the second string of LEDs. The first feedback signal is proportional to current in said first string of LEDs and said second feedback signal is proportional to current in said second string of LEDs. The method of this embodiment may also include controlling a voltage drop of at least the first string of LEDs to adjust the current of the first string of LEDs relative to the second string of LEDs, based on, at least in part, the comparing of the first and second feedback signals. Of course, many alternatives, variations, and modifications are possible without departing from this embodiment.
    Type: Grant
    Filed: October 11, 2005
    Date of Patent: December 7, 2010
    Assignee: O2Micro International Limited
    Inventors: Da Liu, Yung-Lin Lin
  • Patent number: 7825627
    Abstract: An apparatus includes battery gauge circuitry implemented on an integrated circuit. The battery gauge circuitry includes a plurality of switches that individually open in response to a voltage reduction on a battery cell associated with a respective one of the switches. The battery gauge circuitry also includes a logic device that determines if at least one of the switches is open. The battery gauge circuitry also includes a register that stores data that indicates if at least one switch is open. The battery gauge circuitry also includes a controller that initiates halting power delivery to a load if at least one of the switches is open. The controller also identifies the open switch.
    Type: Grant
    Filed: July 17, 2006
    Date of Patent: November 2, 2010
    Assignee: O2Micro International Limited
    Inventor: Constantin Bucur
  • Patent number: 7822956
    Abstract: A computer system includes a system CPU responsive to a control signal to load a first operating system or a second operating system. The first operating system is run by the computer system in a first operation mode and the second operating system is run by the computer system in a second entertainment mode. A PC operating in an entertainment mode may operate a variety of entertainment software applications. A quick boot process is also provided. The quick boot process may include an accelerated BIOS boot process that defers and delays appropriate tasks. The quick boot process may also include: detecting a condition; performing a BIOS boot process; loading an image file associated with the condition; and executing the image file associated with the condition. The condition may be that associated hardware is unchanged from a previous boot. A parental control system is also disclosed.
    Type: Grant
    Filed: April 3, 2003
    Date of Patent: October 26, 2010
    Assignee: O2Micro International Limited
    Inventors: Sterling Du, James Lam, Bruce Denning
  • Patent number: 7812546
    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 6, 2008
    Date of Patent: October 12, 2010
    Assignee: O2Micro International Limited
    Inventor: Sheng Tai Lee
  • Patent number: 7808548
    Abstract: A method according to one embodiment includes coupling at least one power supply to a power bus comprised in a digital camera. The method of this embodiment may also include allocating power to at least one component of the digital camera by coupling at least one component to the power bus based on at least one power management priority rule. Of course, many alternatives, variations, and modifications are possible without departing from this embodiment.
    Type: Grant
    Filed: December 30, 2004
    Date of Patent: October 5, 2010
    Assignee: O2Micro International Limited
    Inventors: Vlad Popescu-Stanseti, Liusheng Liu, James Lam, Bruce S. Denning, Sterling Du
  • Patent number: 7804273
    Abstract: A selector circuit configured to select among a DC power source and a plurality of batteries for an electronic device. The selector circuit includes a first comparator configured to compare a first input signal representative of a voltage level of the DC power source with a first threshold level and provide a first output signal representative of a difference between the first input signal and the first threshold level, and a selector output circuit. The selector output circuit is configured to provide selector output signals that control selection among the DC power source and the plurality of batteries. The selector output circuit providing said selector output signals to select the DC source and deselect the plurality of batteries if the first output signal is representative of the voltage level of said DC power source being greater than the first threshold level.
    Type: Grant
    Filed: March 10, 2009
    Date of Patent: September 28, 2010
    Assignee: O2Micro International Limited
    Inventors: Vlad Popescu-Stanesti, Marian Niculae, Constantin Bucur
  • Patent number: 7791469
    Abstract: A method and system for tracking a portable device. A tracking system includes a portable device, a first Radio Frequency (RF) module, and a second RF module. The first Radio Frequency (RF) module is installed in the portable device for transmitting a wireless signal. The second RF module is used for receiving the wireless signal. When a received amplitude of the wireless signal that is received by the second RF module is less than a predetermined value, the second RF module generates an alert.
    Type: Grant
    Filed: October 11, 2006
    Date of Patent: September 7, 2010
    Assignee: O2Micro International Limited
    Inventors: Jiwei Chen, James Lam
  • Patent number: 7791314
    Abstract: A power supply topology according to one embodiment includes a first path coupled to a controllable DC power source, a second path coupled to a rechargeable battery, and a third path coupled to a system load, the three paths coupled to a common node. The topology may further include a unidirectional switch coupled to the first path and a selectively unidirectional switch coupled to the second path. The topology may further include a power management control circuit including a wake up circuit having a comparison circuit and an output decision circuit. Of course, many alternatives, variations, and modifications are possible without departing from this embodiment.
    Type: Grant
    Filed: March 25, 2008
    Date of Patent: September 7, 2010
    Assignee: O2Micro International Limited
    Inventors: Constantin Bucur, Vlad Mihail Popescu-Stanesti, Marian Niculae, Daryl Nees
  • Patent number: 7791313
    Abstract: A selector circuit configured to select among a DC power source and a plurality of batteries for an electronic device. The selector circuit is responsive to an output signal from an associated power management unit. The selector circuit is further configured to permit parallel operation of two or more of the batteries. The selector circuit may further act to independently verify power conditions and override instructions from the PMU in certain instances to enhance power supply safety and battery life such as by preventing inter battery current flow from a higher potential battery to a lower potential battery coupled in parallel.
    Type: Grant
    Filed: February 10, 2009
    Date of Patent: September 7, 2010
    Assignee: O2Micro International Limited
    Inventors: Vlad Popescu Stanesti, Marian Niculae, Constantin Bucur
  • Patent number: 7777425
    Abstract: A multi-lamp backlight system is disclosed. The multi-lamp backlight system includes a plurality of lamps, an inverter circuit and a current balance circuit. The inverter circuit is capable of converting a DC input signal to a pair of AC output signals, which have a 180 degree phase shift. The pair of AC output signals are delivered to the plurality of lamps. The current balance circuit is connected to the low voltage sides of the plurality of lamps for balancing the lamp currents.
    Type: Grant
    Filed: May 30, 2007
    Date of Patent: August 17, 2010
    Assignee: O2Micro International Limited
    Inventors: Houng-Kuo Hsu, Chu-Chang Chen, Ching-Chuan Kuo
  • Patent number: 7777463
    Abstract: A method includes coupling a variable output DC power source to power control circuitry, and detecting a type of the variable output DC power source in response to the coupling operation. In one embodiment, the detecting operation may include sending an interrogation signal from the power control circuitry to the variable output DC power source, and evaluating a response to the interrogation signal to determine the type of said variable output DC power source. Power control circuitry may include source type recognition circuitry configured to detect a type of a variable output DC power source in response to a coupling of the variable output DC power source to the power control circuitry.
    Type: Grant
    Filed: April 25, 2005
    Date of Patent: August 17, 2010
    Assignee: O2Micro International Limited
    Inventors: Marian Niculae, Constantin Bucur, William Densham
  • Patent number: 7772882
    Abstract: A system for FPGA (Field Programmable Gate Array) upgrade includes: an FPGA, a FLASH memory and a CPLD. The FLASH memory includes a first section configured to store a workable version of bit files for the FPGA and a second section configured to store a backup version of bit files for the FPGA. The CPLD is coupled to the FPGA and the FLASH memory. The CPLD is configured to download the bit files from the FLASH memory to the FPGA to provide the FPGA with functionality. As a result, the CPLD communicates with CPU to upgrade the bit files in the FLASH memory, and indicates to the CPU which version of bit files has been downloaded to the FPGA.
    Type: Grant
    Filed: June 23, 2008
    Date of Patent: August 10, 2010
    Assignee: O2Micro International Limited
    Inventors: Licai Fang, Lin Gan, Shunguang Ding, Jyshyang Chen
  • Patent number: 7768806
    Abstract: A DC/AC inverter and method thereof are disclosed. The DC/AC inverter for driving a load includes a DC power supply for supplying a DC input voltage, a converter circuit coupled to the DC power supply which converts the DC input voltage into an AC signal used to drive the load, and a control circuit coupled to the converter circuit which sets a frequency of the AC signal. The control circuit is further capable of operating the DC/AC inverter in a fixed frequency mode and in a variable frequency mode in accordance with the DC input voltage and the load condition.
    Type: Grant
    Filed: December 11, 2006
    Date of Patent: August 3, 2010
    Assignee: O2Micro International Limited
    Inventors: Yung-Lin Lin, Da Liu
  • Patent number: 7764021
    Abstract: A method according to one embodiment may include supplying ignition power and steady state power to at least one lamp. The method of this embodiment may also include receiving, during an ignition period of said lamp, a feedback signal indicative of power supplied to said lamp; comparing said feedback signal to a signal that is approximately equal to a signal indicative of steady state power; and maintaining a supply of ignition power to said lamp while said feedback signal remains below said signal indicative of said steady state power. Of course, many alternatives, variations, and modifications are possible without departing from this embodiment.
    Type: Grant
    Filed: April 14, 2005
    Date of Patent: July 27, 2010
    Assignee: O2Micro International Limited
    Inventors: Da Liu, Sheng Tai Lee, Ching Chuan Kuo
  • Publication number: 20100171502
    Abstract: A battery pack including at least one battery cell, a switch, and battery state monitoring circuitry. The battery state monitoring circuitry may be configured to control an ON resistance of the switch to a first ON resistance when the switch is ON and the battery pack is in a stand-by-state and to control the ON resistance to a second ON resistance when the switch is ON and said battery pack is not in said stand-by-state, the first ON resistance greater than the second ON resistance. A cordless electrical device and method consistent with embodiments are also provided.
    Type: Application
    Filed: March 23, 2010
    Publication date: July 8, 2010
    Applicant: O2MICRO INTERNATIONAL LIMITED
    Inventors: Constantin Bucur, Marian Niculae
  • Publication number: 20100171467
    Abstract: A battery pack including at least one battery cell, a switch, and battery state monitoring circuitry. The battery state monitoring circuitry may be configured to control an ON resistance of the switch to a first ON resistance when the switch is ON and the battery pack is in a stand-by-state and to control the ON resistance to a second ON resistance when the switch is ON and said battery pack is not in said stand-by-state, the first ON resistance greater than the second ON resistance. A cordless electrical device and method consistent with embodiments are also provided.
    Type: Application
    Filed: March 23, 2010
    Publication date: July 8, 2010
    Applicant: O2MICRO INTERNATIONAL LIMITED
    Inventors: Constantin Bucur, Marian Niculae
  • Patent number: 7719211
    Abstract: A method according to one embodiment may include generating AC voltage and current and a striking voltage. The method of this embodiment may also include generating striking voltage and steady-state voltage for at least two lamp loads. The method of this embodiment may also include coupling at least two lamp loads in parallel. The method of this embodiment may also include coupling current balancing circuitry to the at least two lamp loads and providing, by the current balancing circuitry simultaneous striking voltage to the at least two lamps loads. The method of this embodiment may also include balancing, by the current balancing circuitry, AC current through the at least two lamp loads. Of course, many alternatives, variations, and modifications are possible without departing from this embodiment.
    Type: Grant
    Filed: May 13, 2008
    Date of Patent: May 18, 2010
    Assignee: O2Micro International Limited
    Inventors: Ching Chuan Kuo, Houng Kuo Hsu
  • Patent number: 7719236
    Abstract: A portable electrical device may include a DC to DC converter coupled to a common node, a load coupled to the common node, and a controller configured to control the DC to DC converter. The DC to DC converter may be configured to provide a charging current to a rechargeable battery from an adapter when the controller operates said DC to DC converter in a first adapter supply mode. The DC to DC converter may be configured to provide a battery supply current to the load via the common node when the controller operates the DC to DC converter in a second adapter supply mode. The adapter supply current and the battery supply current may add together at the common node to simultaneously provide a load supply current to the load in the second adapter supply mode.
    Type: Grant
    Filed: November 18, 2005
    Date of Patent: May 18, 2010
    Assignee: O2Micro International Limited
    Inventor: Alexandru Hartular
  • Patent number: 7719247
    Abstract: A DC/DC converter 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: Grant
    Filed: September 29, 2008
    Date of Patent: May 18, 2010
    Assignee: O2Micro International Limited
    Inventors: Laszlo Lipcsei, Sorin Hornet