Patents by Inventor Liusheng Liu
Liusheng Liu 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).
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Patent number: 7589499Abstract: An over voltage transient controller to protect a rechargeable battery from an over voltage transient condition. The over voltage transient controller may comprise a comparator to compare a first signal with a second signal representative of a reference voltage level and to provide an output signal representative of an over voltage transient condition to a switch if the first signal is greater than or equal to the second signal. The switch is responsive to the output signal to protect the rechargeable battery from the over voltage transient condition. The over voltage transient controller may further comprise a DAC, wherein the second signal is based, at least in part, on an output of the DAC. An apparatus comprising a charge switch and such an over voltage transient controller is also provided.Type: GrantFiled: April 27, 2004Date of Patent: September 15, 2009Assignee: O2Micro International LimitedInventors: Bruce S. Denning, Guoxing Li, Liusheng Liu
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Patent number: 7557540Abstract: A method and system for measuring the remaining capacity of a battery with open circuit voltage detection is disclosed. The method includes the steps of measuring an open circuit voltage, obtaining an initial capacity based on the open circuit voltage, initializing an accumulation counter with the initial capacity, adjusting the accumulation counter, and obtaining the remaining capacity based on the accumulation counter. The method further includes the step of calibrating the accumulation counter to eliminate accumulated error and offset resulting from the previous operation of adjusting the accumulation counter.Type: GrantFiled: June 15, 2006Date of Patent: July 7, 2009Assignee: O2Micro International Ltd.Inventors: William Kao, Vincent Hou, Liusheng Liu
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Publication number: 20090001937Abstract: A power management system includes a battery pack having a battery controller and includes an adapter operable for charging the battery pack and powering a system load. The adapter generates a power recognition signal indicative of a maximum adapter power and receives a control signal. The battery controller in the battery pack receives the power recognition signal and generates the control signal to adjust an output power of the adapter according to a status of the battery pack and a status of the system load.Type: ApplicationFiled: June 12, 2008Publication date: January 1, 2009Applicant: O2Micro, Inc.Inventors: William Densham, Han-Jung Kao, Liusheng Liu
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Publication number: 20080218127Abstract: A battery management system comprises a control circuit and an adapter. The control circuit can be used to generate a control signal according to a status of each cell of a plurality of cells in a battery pack. The adapter receives the control signal and charges the battery pack. An output power of the adapter is adjusted according to the control signal.Type: ApplicationFiled: June 20, 2007Publication date: September 11, 2008Inventors: Han-Jung Kao, Jiankui Guo, Liusheng Liu, Ruichao Tang, Guoxing Li, Xiaohua Hou, Zhengming Zhang
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Publication number: 20080150487Abstract: A battery pre-charging circuit. The pre-charging circuit comprises 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 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 a battery voltage over the battery is below a first battery voltage level.Type: ApplicationFiled: December 21, 2006Publication date: June 26, 2008Inventors: Shiqiang Liu, Guoxing Li, Sean Xiao, Liusheng Liu
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Publication number: 20070257642Abstract: A monitoring circuit for monitoring a plurality of battery cells of a battery pack includes a plurality of temperature sensors, an analog to digital converter (ADC) and a processor. The plurality of temperature sensors is used for sensing temperatures of the plurality of battery cells and outputting a plurality of analog temperature voltage signals representative of the temperature of the plurality of battery cells. The analog to digital converter (ADC) is adapted to receive the plurality of analog temperature voltage signals and to convert each of the plurality of analog temperature voltage signals to a plurality of individual digital signals. The processor is adapted to generate an alert signal when an individual digital signal is not within a predetermined range.Type: ApplicationFiled: April 24, 2007Publication date: November 8, 2007Inventors: Sean Xiao, Kevin Sheng, Guoxing Li, Liusheng Liu
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Publication number: 20070205908Abstract: A method and apparatus are provided to indicate battery capacity status. Different blinking frequencies of the LED correspond to different battery states of charge. Furthermore, the present invention provides a smooth visual brightness change of the LED by providing the appropriate LED current according to human eye characteristic.Type: ApplicationFiled: March 1, 2007Publication date: September 6, 2007Inventors: Sterling Du, Liusheng Liu, Oleksandr Kokorin
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Publication number: 20070188950Abstract: A protection device for non-common ground buses is disclosed. The protection circuit includes a controller, a level shifter, a first group of switches, and a second group of switches. The controller together with the level shifter controls the first group and second group of switches. The non-common ground buses will be isolated when at least one group of the switches are turned off in an abnormal condition.Type: ApplicationFiled: December 27, 2006Publication date: August 16, 2007Inventors: Liusheng Liu, Guoxing Li, Shiqiang Liu, Sean Xiao
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Publication number: 20070075684Abstract: A circuit is used for controlling charging and discharging a battery. The circuit comprises a first MOSFET for controlling discharging the battery, and a second MOSFET coupled in series to the battery and the first MOSFET for controlling charging the battery. The first and second MOSFETs have body diodes respectively, and the first body diode of the first MOSFET and the second body diode of the second MOSFET are coupled in opposite directions. A load is coupled to the battery and a common node between the first and second MOSFETs such that power in the battery is delivered to said load when the first MOSFET is turned on. The circuit further comprises a power source coupled to the second switch in series and power is delivered from the power source to the battery when the first and second MOSFETs are turned on.Type: ApplicationFiled: August 22, 2006Publication date: April 5, 2007Inventors: Shiqiang Liu, Sean Xiao, Guoxing Li, Liusheng Liu
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Patent number: 7196652Abstract: An analog to digital converter may include an input switch array configured to alternately sample a first and a second input signal to a first and a second input capacitor during two different sample time intervals, an integrator having a first and second integration capacitor, and a cross switch array coupled to the input switch array and the integrator. The cross switch array may be configured to alternately transfer charges from the first and second input capacitors to the first and second integration capacitors during two different transfer time intervals. A system including an analog to digital converter consistent with an embodiment and an associated method of sampling and transferring charges in an analog to digital converter are also provided.Type: GrantFiled: May 31, 2005Date of Patent: March 27, 2007Assignee: 02Micro International LimitedInventors: Liusheng Liu, Guoxing Li
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Patent number: 7180268Abstract: Battery charging circuitry and systems are provided. One embodiment may include at least one switch having a full conduction state and a controllable conduction state and switch control circuitry capable of sensing a condition. The switch control circuitry may further be capable of generating at least one control signal capable of controlling the conduction state of the switch based on, at least in part, the sensed condition.Type: GrantFiled: April 27, 2004Date of Patent: February 20, 2007Assignee: O2Micro International LimitedInventors: Bruce S. Denning, Guoxing Li, Liusheng Liu
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Publication number: 20070024243Abstract: Battery protection circuitry and method are disclosed. A battery is protected from a large current overdrawn condition by setting a discharge switch into a controllable conduction state. After the discharge switch is in the controllable conduction state, a tickle discharge current is gradually generated under control of a switch control signal. The trickle discharge current can be used to determine whether the large current overdrawn condition still exists. When the large current overdrawn condition is removed, the discharge switch is turned back on.Type: ApplicationFiled: September 29, 2006Publication date: February 1, 2007Inventors: Liusheng Liu, Bruce Denning
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Patent number: 7161520Abstract: An analog to digital converter (ADC) includes a cross switch array coupled between an input switch array and an integrator configured to alternately transfer charges from a first input capacitor and a second input capacitor to a first integration capacitor and a second integration capacitor thereby improving linearity problems caused by capacitor mismatching. The cross switch array may also be configured to transfer charges from the first input capacitor to the first integration capacitor and from the second input capacitor to the second integration capacitor during a first charge transfer time interval, and from the first input capacitor to the second integration capacitor and from the second input capacitor to the first integration capacitor during a second charge transfer time interval. A sensing system including and ADC consistent with the invention is also provided. Various methods of transferring charges in an ADC are also provided.Type: GrantFiled: May 4, 2004Date of Patent: January 9, 2007Assignee: O2Micro International LimitedInventors: Liusheng Liu, Guoxing Li
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Publication number: 20060255769Abstract: 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: ApplicationFiled: July 24, 2006Publication date: November 16, 2006Applicant: O2MICRO, INC.Inventors: Liusheng Liu, Guoxing Li
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Patent number: 7081737Abstract: 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: GrantFiled: June 19, 2003Date of Patent: July 25, 2006Assignee: O2Micro International LimitedInventors: Liusheng Liu, Guoxing Li
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Publication number: 20050219105Abstract: An analog to digital converter may include an input switch array configured to alternately sample a first and a second input signal to a first and a second input capacitor during two different sample time intervals, an integrator having a first and second integration capacitor, and a cross switch array coupled to the input switch array and the integrator. The cross switch array may be configured to alternately transfer charges from the first and second input capacitors to the first and second integration capacitors during two different transfer time intervals. A system including an analog to digital converter consistent with an embodiment and an associated method of sampling and transferring charges in an analog to digital converter are also provided.Type: ApplicationFiled: May 31, 2005Publication date: October 6, 2005Inventors: Liusheng Liu, Guoxing Li
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Publication number: 20050212489Abstract: An over voltage transient controller to protect a rechargeable battery from an over voltage transient condition. The over voltage transient controller may comprise a comparator to compare a first signal with a second signal representative of a reference voltage level and to provide an output signal representative of an over voltage transient condition to a switch if the first signal is greater than or equal to the second signal. The switch is responsive to the output signal to protect the rechargeable battery from the over voltage transient condition. The over voltage transient controller may further comprise a DAC, wherein the second signal is based, at least in part, on an output of the DAC. An apparatus comprising a charge switch and such an over voltage transient controller is also provided.Type: ApplicationFiled: April 27, 2004Publication date: September 29, 2005Inventors: Bruce Denning, Guoxing Li, Liusheng Liu
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Publication number: 20050212484Abstract: Battery charging circuitry and systems are provided. One embodiment may include at least one switch having a full conduction state and a controllable conduction state and switch control circuitry capable of sensing a condition. The switch control circuitry may further be capable of generating at least one control signal capable of controlling the conduction state of the switch based on, at least in part, the sensed condition.Type: ApplicationFiled: April 27, 2004Publication date: September 29, 2005Inventors: Bruce Denning, Guoxing Li, Liusheng Liu
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Patent number: 6930515Abstract: Level shifting and amplified level shifting circuit topologies are provided that include two or more level shifting or amplified level shifting circuits. The level shifting circuits receive a variable and fixed input and generate a variable and fixed output that are level shifted with respect to the input signals. The amplified level shifting circuits receive a variable and fixed input and generate a variable and fixed output that are level shifted and amplified with respect to the input signals. These circuits may be utilized to form a detection circuit that detects a difference in the output signals.Type: GrantFiled: September 2, 2004Date of Patent: August 16, 2005Assignee: O2 Micro International LimitedInventors: Liusheng Liu, Guoxing Li
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Patent number: 6924667Abstract: Level shifting and amplified level shifting circuit topologies are provided that include two or more level shifting or amplified level shifting circuits. The level shifting circuits receive a variable and fixed input and generate a variable and fixed output that are level shifted with respect to the input signals. The amplified level shifting circuits receive a variable and fixed input and generate a variable and fixed output that are level shifted and amplified with respect to the input signals. These circuits may be utilized to form a detection circuit that detects a difference in the output signals.Type: GrantFiled: July 19, 2002Date of Patent: August 2, 2005Assignee: O2Micro International LimitedInventors: Liusheng Liu, Guoxing Li