Patents by Inventor Xujun Liu
Xujun 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: 10116219Abstract: A method comprises connecting a first resonant converter and a second resonant converter in parallel, detecting a first signal indicating a first soft switching process of the first resonant converter and a second signal indicating a second soft switching process of the second resonant converter and adjusting a first switching frequency of the first resonant converter by a first control circuit and a second switching frequency of the second resonant converter by a second control circuit until a load current flowing through the first resonant converter is substantially equal to a load current flowing through the second resonant converter.Type: GrantFiled: September 12, 2016Date of Patent: October 30, 2018Assignee: Futurewei Technologies, Inc.Inventors: Daoshen Chen, Heping Dai, Xujun Liu, Zhihua Liu, Liming Ye, Dianbo Fu, Ce Liu, Bing Cai
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Publication number: 20180226035Abstract: The present disclosure discloses a GOA gate driving circuit includes a plurality of GOA driving units arranged in cascade, each level GOA driving unit includes a pull-up control part, a pull-up part, a first pull-down part and a pull-down holding part; wherein, each stage GOA driving unit further includes a second pull-down part coupled between the gate control signal and the reference low level signal, the second pull-down part being controlled by a pull-down signal for lowering the gate control signal to the reference low level signal; the phase of the pull-down signal lags behind the latter two-stage scan driving signal, and the pull-down signal is provided by a separate control chip. The present disclosure further discloses a liquid crystal display including a GOA gate driving circuit as described above.Type: ApplicationFiled: January 17, 2017Publication date: August 9, 2018Applicant: Shenzhen China Star Optoelectronics Technology Co., Ltd.Inventors: Tianhong WANG, Xujun LIU, Yi-fang CHOU
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Publication number: 20180102713Abstract: A device comprises a gate drive bridge coupled between a bias voltage of a power converter and ground and a transformer connected to the gate drive bridge, wherein the transformer comprises a primary winding connected to two legs of the gate drive bridge respectively and a plurality of secondary windings configured to generate gate drive signals for low side switches, high side switches and secondary switches of the power converter.Type: ApplicationFiled: December 12, 2017Publication date: April 12, 2018Inventors: Daoshen Chen, Heping Dai, Xujun Liu, Liming Ye, Dianbo Fu
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Patent number: 9876435Abstract: A method comprises providing a resonant converter comprising a switching network comprising a first high-side switch, a second high-side switch, a first low-side switch and a second low-side switch, a resonant tank coupled between the switching network and a transformer and a rectifier coupled to a secondary side of the transformer, coupling a driver to the switching network and the rectifier, wherein the driver includes a first winding coupled to the rectifier, a second winding coupled to the first high-side switch and a third winding coupled to the second high-side switch, detecting a signal indicating a soft switching process of the driver and adjusting a resonant frequency of the driver until the resonant frequency of the driver approximately matches a switch frequency of the resonant converter.Type: GrantFiled: October 19, 2016Date of Patent: January 23, 2018Assignee: Futurewei Technologies, Inc.Inventors: Daoshen Chen, Heping Dai, Xujun Liu, Liming Ye, Dianbo Fu
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Patent number: 9812968Abstract: A converter comprises a switch network coupled to a power source, wherein the switch network comprises a plurality of power switches, a magnetic device coupled to the switch network, a detector coupled to the magnetic device through a magnetic coupling and a control circuit configured to receive a zero voltage switching signal from the detector and adjust gate drive signals of the power switches based upon the zero voltage switching signal.Type: GrantFiled: November 19, 2014Date of Patent: November 7, 2017Assignee: Futurewei Technologies, Inc.Inventors: Jinbo Huang, Xujun Liu, Dianbo Fu, Liming Ye, Heping Dai, Daoshen Chen
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Publication number: 20170250686Abstract: A method and an apparatus for driving a power switch tube. The apparatus includes an input unit, a drive unit, a transformer and a power switch tube. The input unit is connected to the drive unit, which is configured to input a group of drive signals, and the group of drive signals includes four drive signals, where the first drive signal and the second are complementary signals, and a dead time exists; the third drive signal and the fourth are complementary signals, and a dead time exists; the phase difference between the first drive signal and the third is 180 degrees, and the phase difference between the second drive signal and the fourth is 180 degrees; the drive unit is configured to power on a field winding of the transformer; and the transformer provides a drive voltage signal for the power switch tube.Type: ApplicationFiled: May 15, 2017Publication date: August 31, 2017Inventor: Xujun Liu
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Patent number: 9680467Abstract: A method and an apparatus for driving a power switch tube. The apparatus includes an input unit, a drive unit, a transformer and a power switch tube. The input unit is connected to the drive unit, which is configured to input a group of drive signals, and the group of drive signals includes four drive signals, where the first drive signal and the second are complementary signals, and a dead time exists; the third drive signal and the fourth are complementary signals, and a dead time exists; the phase difference between the first drive signal and the third is 180 degrees, and the phase difference between the second drive signal and the fourth is 180 degrees; the drive unit is configured to power on a field winding of the transformer; and the transformer provides a drive voltage signal for the power switch tube.Type: GrantFiled: March 25, 2014Date of Patent: June 13, 2017Assignee: Huawei Technologies Co., Ltd.Inventor: Xujun Liu
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Publication number: 20170040903Abstract: A method comprises providing a resonant converter comprising a switching network comprising a first high-side switch, a second high-side switch, a first low-side switch and a second low-side switch, a resonant tank coupled between the switching network and a transformer and a rectifier coupled to a secondary side of the transformer, coupling a driver to the switching network and the rectifier, wherein the driver includes a first winding coupled to the rectifier, a second winding coupled to the first high-side switch and a third winding coupled to the second high-side switch, detecting a signal indicating a soft switching process of the driver and adjusting a resonant frequency of the driver until the resonant frequency of the driver approximately matches a switch frequency of the resonant converter.Type: ApplicationFiled: October 19, 2016Publication date: February 9, 2017Inventors: Daoshen Chen, Heping Dai, Xujun Liu, Liming Ye, Dianbo Fu
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Publication number: 20160380547Abstract: A method comprises connecting a first resonant converter and a second resonant converter in parallel, detecting a first signal indicating a first soft switching process of the first resonant converter and a second signal indicating a second soft switching process of the second resonant converter and adjusting a first switching frequency of the first resonant converter by a first control circuit and a second switching frequency of the second resonant converter by a second control circuit until a load current flowing through the first resonant converter is substantially equal to a load current flowing through the second resonant converter.Type: ApplicationFiled: September 12, 2016Publication date: December 29, 2016Inventors: Daoshen Chen, Heping Dai, Xujun Liu, Zhihua Liu, Liming Ye, Dianbo Fu, Ce Liu, Bing Cai
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Publication number: 20160329817Abstract: A power supply converter includes a power input circuit, which generates and outputs a first alternating current voltage; a transformer, which converts the first alternating current voltage into a second alternating current voltage; a power output circuit, which converts the second alternating current voltage into an output voltage, and outputs the output voltage; a resonant circuit and a correction circuit, which senses the first alternating current voltage to obtain a detection signal, and detects a value of a ringing signal in the detection signal, and sends a control signal to the power input circuit according to the value of the ringing signal, to adjust the frequency of the first alternating current voltage to be equal to the resonance frequency of the resonant circuit or be around the resonance frequency, so as to adjust the value of the ringing signal to reach a minimum value.Type: ApplicationFiled: July 19, 2016Publication date: November 10, 2016Inventors: Xujun Liu, Liming Ye
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Patent number: 9479073Abstract: An apparatus comprises a bridge coupled between a bias voltage and ground, wherein the bridge comprises a first switch and a second switch connected in series and coupled between the bias voltage and ground and a third switch and a fourth switch connected in series and coupled between the bias voltage and ground, a resonant device coupled to the bridge, wherein the resonant device comprises a fixed capacitance, a gate capacitance and a magnetizing inductance, a transformer coupled to the resonant device, wherein the transformer comprises a primary winding and a plurality of secondary windings.Type: GrantFiled: November 12, 2013Date of Patent: October 25, 2016Assignee: Futurewei Technologies, Inc.Inventors: Daoshen Chen, Heping Dai, Xujun Liu, Liming Ye, Dianbo Fu
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Patent number: 9467054Abstract: An apparatus comprises a magnetic device coupled to an inductor-inductor-capacitor (LLC) resonant converter, an ac current sensing circuit coupled to the magnetic device, an average current sensing circuit coupled to the ac current sensing circuit and a reference voltage source coupled to the average current sensing circuit, wherein the reference voltage source is configured such that a magnitude of an average signal from the average current sensing circuit is greater than a voltage level of the reference voltage source.Type: GrantFiled: November 7, 2013Date of Patent: October 11, 2016Assignee: Futurewei Technologies, Inc.Inventors: Heping Dai, Xujun Liu, Liming Ye, Daoshen Chen
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Patent number: 9444346Abstract: A converter comprises an input stage coupled to a power source, wherein the input stage comprises a plurality of power switches, a resonant tank coupled to the plurality of power switches, a transformer coupled to the resonant tank, an output stage coupled to the transformer, an efficiency point tracking indicator coupled to the converter, a detector coupled to the efficiency point tracking indicator and a control circuit configured to receive an efficiency point tracking signal from the detector and adjust a switching frequency of the power switches based upon the efficiency point tracking signal.Type: GrantFiled: October 17, 2013Date of Patent: September 13, 2016Assignee: FUTUREWEI TECHNOLOGIES, INC.Inventors: Daoshen Chen, Heping Dai, Xujun Liu, Zhihua Liu, Liming Ye, Dianbo Fu, Ce Liu, Bing Cai
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Patent number: 9350260Abstract: A method comprises providing a resonant converter comprising a switching network comprising a plurality of switches, a resonant tank coupled between the switching network and a transformer, wherein the resonant tank comprises a series resonant inductor coupled to a switching network and the transformer and a series resonant capacitor coupled to the switching network and the transformer and a driver having an adjustable bias voltage and in response to a startup process of the resonant converter, configuring the switching network to operate a switching frequency higher than a resonant frequency of the resonant tank.Type: GrantFiled: November 7, 2013Date of Patent: May 24, 2016Assignee: FUTUREWEI TECHNOLOGIES, INC.Inventors: Heping Dai, Daoshen Chen, Xujun Liu, Liming Ye
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Publication number: 20160141960Abstract: A converter comprises a switch network coupled to a power source, wherein the switch network comprises a plurality of power switches, a magnetic device coupled to the switch network, a detector coupled to the magnetic device through a magnetic coupling and a control circuit configured to receive a zero voltage switching signal from the detector and adjust gate drive signals of the power switches based upon the zero voltage switching signal.Type: ApplicationFiled: November 19, 2014Publication date: May 19, 2016Inventors: Jinbo Huang, Xujun Liu, Dianbo Fu, Liming Ye, Heping Dai, Daoshen Chen
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Patent number: 9143044Abstract: An embodiment apparatus comprises a first two-piecewise linear approximation generator and a second two-piecewise linear approximation generator coupled to an output of the first two-piece wise linear approximation generator. The second two-piecewise linear approximation generator generates a dead time inversely proportional to the output of the first two-piece wise linear approximation generator. A gate drive generator is configured to generate a primary switch drive signal and an auxiliary switch drive signal complementary to the primary switch drive signal. In addition, the dead time between the primary switch drive signal and the auxiliary switch drive signal is adjustable when the power converter operates in a light load condition.Type: GrantFiled: September 13, 2012Date of Patent: September 22, 2015Assignee: Futurewei Technologies, Inc.Inventors: Liming Ye, Xujun Liu
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Publication number: 20150131329Abstract: An apparatus comprises a bridge coupled between a bias voltage and ground, wherein the bridge comprises a first switch and a second switch connected in series and coupled between the bias voltage and ground and a third switch and a fourth switch connected in series and coupled between the bias voltage and ground, a resonant device coupled to the bridge, wherein the resonant device comprises a fixed capacitance, a gate capacitance and a magnetizing inductance, a transformer coupled to the resonant device, wherein the transformer comprises a primary winding and a plurality of secondary windings.Type: ApplicationFiled: November 12, 2013Publication date: May 14, 2015Applicant: FutureWei Technologies, Inc.Inventors: Daoshen Chen, Heping Dai, Xujun Liu, Liming Ye, Dianbo Fu
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Publication number: 20150124489Abstract: An apparatus comprises a magnetic device coupled to an inductor-inductor-capacitor (LLC) resonant converter, an ac current sensing circuit coupled to the magnetic device, an average current sensing circuit coupled to the ac current sensing circuit and a reference voltage source coupled to the average current sensing circuit, wherein the reference voltage source is configured such that a magnitude of an average signal from the average current sensing circuit is greater than a voltage level of the reference voltage source.Type: ApplicationFiled: November 7, 2013Publication date: May 7, 2015Applicant: FutureWei Technologies, Inc.Inventors: Heping Dai, Xujun Liu, Liming Ye, Daoshen Chen
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Publication number: 20150124488Abstract: A method comprises providing a resonant converter comprising a switching network comprising a plurality of switches, a resonant tank coupled between the switching network and a transformer, wherein the resonant tank comprises a series resonant inductor coupled to a switching network and the transformer and a series resonant capacitor coupled to the switching network and the transformer and a driver having an adjustable bias voltage and in response to a startup process of the resonant converter, configuring the switching network to operate a switching frequency higher than a resonant frequency of the resonant tank.Type: ApplicationFiled: November 7, 2013Publication date: May 7, 2015Applicant: FutureWei Technologies, Inc.Inventors: Heping Dai, Daoshen Chen, Xujun Liu, Liming Ye
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Publication number: 20150109824Abstract: A converter comprises an input stage coupled to a power source, wherein the input stage comprises a plurality of power switches, a resonant tank coupled to the plurality of power switches, a transformer coupled to the resonant tank, an output stage coupled to the transformer, an efficiency point tracking indicator coupled to the converter, a detector coupled to the efficiency point tracking indicator and a control circuit configured to receive an efficiency point tracking signal from the detector and adjust a switching frequency of the power switches based upon the efficiency point tracking signal.Type: ApplicationFiled: October 17, 2013Publication date: April 23, 2015Applicant: FutureWei Technologies, Inc.Inventors: Daoshen Chen, Heping Dai, Xujun Liu, Zhihua Liu, Liming Ye, Dianbo Fu, Ce Liu, Bing Cai