Patents Assigned to Micro International Limited
  • 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: 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
  • 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: 7701177
    Abstract: A battery pre-charging circuit includes a pre-charging path, a pre-charging switch and a low-voltage pre-charging circuit. The pre-charging path is coupled between a charger and a battery for providing a pre-charging current from the charger to the battery. The pre-charging switch is coupled to the pre-charging path for conducting along the pre-charging path. The low-voltage pre-charging circuit is coupled to the pre-charging switch for controlling the pre-charging switch. The low-voltage pre-charging circuit is configured to switch on the pre-charging switch when the battery voltage is below a first battery voltage level.
    Type: Grant
    Filed: December 21, 2006
    Date of Patent: April 20, 2010
    Assignee: O2Micro International Limited
    Inventors: Shiqiang Liu, Guoxing Li, Sean Xiao, Liusheng Liu
  • Patent number: 7696725
    Abstract: A monitoring circuit for accurately monitoring a voltage level from each of a plurality of battery cells of a battery pack includes an analog to digital converter (ADC) and a processor. The ADC is configured to accept an analog voltage signal from each of the plurality of battery cells and convert each analog voltage signal to a digital signal representative of an accurate voltage level of each battery cell. The processor receives such signals and provides a safety alert signal based on at least one of the signals. The ADC resolution may be adjustable. A balancing circuit provides a balancing signal if at least two of the digital signals indicate a voltage difference between two cells is greater than a battery cell balance threshold. An electronic device including such monitoring and balancing circuits is also provided. Various methods are also provided.
    Type: Grant
    Filed: July 24, 2006
    Date of Patent: April 13, 2010
    Assignee: O2Micro International Limited
    Inventors: Liusheng Liu, Guoxing Li
  • Patent number: 7683577
    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: Grant
    Filed: September 26, 2005
    Date of Patent: March 23, 2010
    Assignee: O2Micro International Limited
    Inventors: Constantin Bucur, Marian Niculae
  • Patent number: 7679324
    Abstract: A communication circuit is used for transmitting data between a plurality of devices which have non-common ground voltages. The communication circuit comprises a plurality of transmitting input nodes coupled to the devices, respectively, a transmitting current path, a plurality of receiving output nodes coupled to the devices, respectively, and a receiving current path. The transmitting current path is coupled to the transmitting input nodes. The current through the transmitting current path is varied according to the input signal of the transmitting input nodes. The receiving current path is coupled to the receiving output nodes. The current through the receiving current path is varied according to the current of the transmitting current path such that data is transmitted from the transmitting input nodes to the receiving output nodes.
    Type: Grant
    Filed: November 18, 2005
    Date of Patent: March 16, 2010
    Assignee: O2Micro International Limited
    Inventors: Sean Xiao, Oleksandr Kokorin
  • Patent number: 7667435
    Abstract: A secondary battery protection circuit may include an over voltage detector circuit configured to monitor a voltage level of an associated cell of a rechargeable battery and provide an output signal to a switch in response to a comparison of the voltage level of the cell to an over voltage threshold level. The switch may be coupled between the rechargeable battery and a DC power source and capable of moving between conducting and non-conducting states. The switch may also be responsive to the output signal to protect the rechargeable battery if the voltage level of said cell is greater than the over voltage threshold level for a time interval less than or equal to a transient time interval.
    Type: Grant
    Filed: July 6, 2007
    Date of Patent: February 23, 2010
    Assignee: O2Micro International Limited
    Inventor: Bruce S. Denning
  • Patent number: 7659702
    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: Grant
    Filed: March 29, 2007
    Date of Patent: February 9, 2010
    Assignee: O2Micro International Limited
    Inventors: Laszlo Lipcsei, Serban Popescu, Sorin Hornet
  • Publication number: 20100026213
    Abstract: A method according to one embodiment may include providing power to at least one light source. The method of this embodiment may also include detecting the frequency of at least one vertical synchronization signal, among a plurality of different synchronization signals, and controlling the power to at least one light source based on, at least in part, the detected frequency of at least one vertical synchronization signal. Of course, many alternatives, variations, and modifications are possible without departing from this embodiment.
    Type: Application
    Filed: October 6, 2009
    Publication date: February 4, 2010
    Applicant: O2Micro International Limited
    Inventors: Yung-Lin Lin, Albert Chang
  • Patent number: 7656684
    Abstract: The present disclosure is directed towards a method for power conversion. The method may include controlling a first rectifier switch coupled to one end of a secondary winding of a transformer via a first control signal. The method may further include controlling a first low side switch via said first control signal, said first low side switch and a first high side switch coupled in series along a first path of a full bridge circuit, a first node located between said first high side switch and said first low side switch. The method may also include controlling a second rectifier switch coupled to an opposite end of said secondary winding via a second control signal.
    Type: Grant
    Filed: April 29, 2008
    Date of Patent: February 2, 2010
    Assignee: O2Micro International Limited
    Inventors: Laszlo Lipcsei, Catalin Popovici