Patents Assigned to 02 Micro International ltd.
  • Patent number: 7531989
    Abstract: The present invention is a battery fuel gauge circuit for measuring the capacity of a battery pack. The battery fuel gauge circuit includes an amplifier circuit, a correction circuit, a plurality of comparators, and a multiplexer. The amplifier circuit can sense a discharge current flowing through a sense resistor and a variable temperature from the battery pack and generate a first and a second voltage signals, which are corrected by the correction circuit and compared with a reference voltage by the plurality of comparators. After correction and comparison, the multiplexer can transmit the compared signals to an external indicating circuit that controls the display of the capacity of the battery pack.
    Type: Grant
    Filed: May 9, 2006
    Date of Patent: May 12, 2009
    Assignee: 02Micro International Ltd.
    Inventor: Stefan Maireanu
  • Patent number: 7526015
    Abstract: A method for processing spread spectrum signals through a two step integration process in a circuit having an intermediate frequency signal preprocessing unit and a plurality of block integrators, wherein the circuit receiving a digitized signal, a local reference signal, and a pseudorandom noise code. The method includes generating a plurality of data streams by the intermediate frequency signal preprocessing unit using the digitized signal and the reference signal, receiving at each block integrator a data stream from the plurality of data streams and the pseudorandom noise code, performing a predetermined number of partial correlations at each block integrator using hybrid correlation technique based on the data stream and the pseudorandom noise code to obtain a predetermined number of partial correlation results, and computing a predetermined number of complete correlation results based on the predetermined number of partial correlation results.
    Type: Grant
    Filed: September 15, 2005
    Date of Patent: April 28, 2009
    Assignee: 02Micro International Ltd.
    Inventors: MingQiang Cheng, ShiJie Li, Bo Yu
  • Patent number: 7498694
    Abstract: A power management device for enabling multiply power sources to supply power to a load. The power management device includes a plurality of switches and a control logic. The plurality of switches are coupled to a plurality of power sources respectively and each switch coupled to each power source. The control logic is capable of selecting a set of switches among the plurality of switches to cooperate in a time-divided fashion to allow the power sources to provide power to the load. The set of switches is selected based on an electrical requirement of the load and an electrical condition of each switch.
    Type: Grant
    Filed: April 12, 2006
    Date of Patent: March 3, 2009
    Assignee: 02Micro International Ltd.
    Inventors: Luyang Luo, Chun Lu, Jianping Xu, Lin Tang
  • Patent number: 7323853
    Abstract: The present invention is a LDO voltage regulator circuit with common-mode feedback. The LDO voltage regulator includes an error amplifier with a common-mode feedback unit, a pass device and a compensation circuit. A signal from the pass device acts as an input signal to the error amplifier and is compared with another input signal, producing a differential signal. The differential signal is amplified and then provided to the pass device. A capacitor in the compensation unit provides frequency compensation to the LDO voltage regulator. The common-mode feedback unit incorporated into the error amplifier greatly improves a slew rate of a gate voltage of the pass device.
    Type: Grant
    Filed: June 30, 2005
    Date of Patent: January 29, 2008
    Assignee: 02Micro International Ltd.
    Inventors: Xiaohu Tang, Wei Wang, XiaoHua Hou, Shiqiang Liu
  • Patent number: 6504735
    Abstract: A DC-DC converter for converting DC power received from a high-voltage DC power supply to a well-regulated output voltage that is significantly lower than the received voltage. The converter includes a regulated voltage-reduction stage which receives high-voltage DC electrical power and supplies DC electrical power at a voltage which is lower than that received. The converter also includes a separately regulated electrically isolated stage, energized by electrical power received from the voltage-reduction stage, that supplies DC electrical power to a load at the significantly lower output voltage. A feedback circuit couples an output signal from the output of the isolation-stage for regulating operation of the voltage-reduction stage and of the isolation stage.
    Type: Grant
    Filed: October 5, 2001
    Date of Patent: January 7, 2003
    Assignee: 02 Micro International Ltd.
    Inventors: Sorin Laurentiu Negru, Gabriel Andreis Nicolescu
  • Patent number: 6359796
    Abstract: An active transient-control circuit included in a power supply responds swiftly to changes occurring in the output-power voltage produced by a power converter to reduce transient changes in the output-power voltage caused by sudden, substantial changes in the electrical current drawn by the load. To respond in this way, when the output-power voltage has a magnitude less than a lower pre-established-voltage threshold, the active transient-control circuit supplies electrical energy directly to the load from the input electrical power thereby augmenting output electrical power supplied to the load by the power converter. Correspondingly, when the output-power voltage has a magnitude that exceeds an upper pre-established-voltage threshold, the active transient-control circuit draws electrical energy directly from the output of the power converter.
    Type: Grant
    Filed: June 21, 2001
    Date of Patent: March 19, 2002
    Assignee: 02 Micro International ltd.
    Inventors: Alexandru Hartular, Sorin Laurentiu Negru, Laszlo Lipcsei