Patents by Inventor Qiang Zong
Qiang Zong 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: 9853563Abstract: The present invention provides an isolated synchronous rectification control circuit, a control device, and a control method. The control circuit includes a power supply module, a reference module, a comparator module, a primary side turn-on determination unit, a secondary intermittent burst estimation unit, a logic unit, and a driver unit. The control device includes a transformer, a bypass capacitor configured to provide a stable voltage, a time constant setting resistor configured to configure a primary side turn-on time constant and a secondary intermittent burst time estimation determination, a synchronous rectification control circuit configured to determine the primary side turn-on based on the current flowing into a time setting terminal, predict a secondary side intermittent burst time, and generate logic control signals to drive the turn-on or turn-off of the synchronous rectifier, and an output capacitor connected to the rectification control circuit to provide an output capacitance.Type: GrantFiled: February 2, 2016Date of Patent: December 26, 2017Assignee: SHENZHEN CHIP HOPE MICRO-ELECTRONICS LTD.Inventors: Qiang Zong, Shouhua Wu, Lei Guan, Zhong Yin
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Publication number: 20170272001Abstract: The present invention provides an isolated synchronous rectification control circuit, a control device, and a control method. The control circuit includes a power supply module, a reference module, a comparator module, a primary side turn-on determination unit, a secondary intermittent burst estimation unit, a logic unit, and a driver unit.Type: ApplicationFiled: February 2, 2016Publication date: September 21, 2017Inventors: QIANG ZONG, SHOUHUA WU, LEI GUAN, ZHONG YIN
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Patent number: 9520868Abstract: A power supply controller is provided for providing a drive current to a control terminal of a power transistor in three time intervals. The controller includes control circuits configured to control the drive current in multiple stages. During a first time interval, first drive current includes a current spike for turning on the power transistor in response to a start of the control signal pulse. During a second time interval, a second drive current includes a ramping current substantially proportional to a magnitude of a current through the power transistor. During a third time interval, current flow to the power transistor is at least partially turned off before an end of the control signal pulse.Type: GrantFiled: April 12, 2013Date of Patent: December 13, 2016Assignee: BCD Semiconductor Manufacturing LimitedInventors: Jinhua Duan, Qiang Zong, Yajiang Zhu
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Patent number: 9391530Abstract: A synchronous rectification circuit for a power supply includes a power switch for coupling to a secondary winding of a transformer of the power supply and an output capacitor of the power supply. The power switch includes a four-terminal MOSFET having a source, a drain, a gate, and a body. A body diode is formed by a junction between the body and the drain or by a junction between the body and the source. The body diode is coupled in parallel to the source and drain of the power transistor. A control circuit is configured to provide a control signal for controlling an on/off state of the power switch in response to a voltage condition of two terminals of the power switch. When the body diode makes a transition from reverse bias to forward bias, the control circuit causes the MOSFET to turn on, and when the forward bias voltage drops below a reference voltage, the control circuit causes the MOSFET to turn off.Type: GrantFiled: August 13, 2013Date of Patent: July 12, 2016Inventors: ShaoHua Fang, BaoZhen Chen, Qiang Zong, YaJiang Zhu
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Patent number: 9083246Abstract: A switched mode power supply (SMPS) includes a transformer with a primary winding, a secondary winding, an auxiliary winding, and a power switch coupled to the primary winding. During one switching cycle, the auxiliary winding provides a feedback signal which includes a first voltage pulse that is induced after the power switch is turned on and a second voltage pulse that is induced after the power switch is turned off. A control circuit includes a circuit for generating a sampling signal for sampling the second voltage pulse in a switching cycle at a time that is determined based on the first voltage pulse in the same switching cycle. A sample-and-hold circuit is configured for sampling and storing the second voltage pulse in response to the sampling signal. A switching signal generating circuit is configured to generate a switching signal for controlling the power switch based on an output of the sample-and-hold circuit.Type: GrantFiled: April 20, 2011Date of Patent: July 14, 2015Assignee: BCD Semiconductor Manufacturing CO., LTd.Inventors: Qiang Zong, Huizhen Zhu, Pingan Zhao, Yajiang Zhu
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Publication number: 20140233272Abstract: A synchronous rectification circuit for a power supply includes a power switch for coupling to a secondary winding of a transformer of the power supply and an output capacitor of the power supply. The power switch includes a four-terminal MOSFET having a source, a drain, a gate, and a body. A body diode is formed by a junction between the body and the drain or by a junction between the body and the source. The body diode is coupled in parallel to the source and drain of the power transistor. A control circuit is configured to provide a control signal for controlling an on/off state of the power switch in response to a voltage condition of two terminals of the power switch. When the body diode makes a transition from reverse bias to forward bias, the control circuit causes the MOSFET to turn on, and when the forward bias voltage drops below a reference voltage, the control circuit causes the MOSFET to turn off.Type: ApplicationFiled: August 13, 2013Publication date: August 21, 2014Applicant: BCD Semiconductor Manufacturing LimitedInventors: ShaoHua Fang, BaoZhen Chen, Qiang Zong, YaJiang Zhu
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Patent number: 8559200Abstract: A startup circuit for a switching-mode power supply (SMPS) includes a first voltage detector configured to trigger the switching-mode power supply from a first operation mode to a second operation mode when an input supply voltage exceeds a first threshold voltage, a current consumption in the first voltage detector in the first operation mode being determined by a reverse leakage current of a diode. A feedback circuit is coupled to the first voltage detector and being capable of maintaining a positive feedback loop. A second voltage detector is coupled to the first voltage detector and the feedback circuit, and is configured to trigger the switching-mode power supply to switch from the second operation mode to the first operation mode when the input supply voltage is below a second threshold voltage.Type: GrantFiled: January 27, 2011Date of Patent: October 15, 2013Assignee: BCD Semiconductor Manufacturing LimitedInventors: Qiang Zong, Shaohua Fang, Reixia Fei, Jia Xie
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Patent number: 8526202Abstract: A synchronous rectification circuit for a power converter includes a power switch coupled to a transformer and an output capacitor and a switching control circuit configured to provide a control signal to the power switch in response to a first state and a second state of the voltage across the power switch. In the switching control circuit, the second state is determined prior to the first state is determined. In an embodiment, the switching control circuit includes a voltage comparing unit configured to act in response to the first and second inputs. The voltage comparing unit is also configured to output a logic signal according to the voltage difference between the sensed voltage drop across the power switch and a reference threshold voltage. A logic processing circuit is coupled to the voltage comparing unit and configured to provide the first state and the second state of the voltage across the power switch.Type: GrantFiled: October 22, 2009Date of Patent: September 3, 2013Assignee: BCD Semiconductor Manufacturing LimitedInventors: ShaoHua Fang, BaoZhen Chen, Qiang Zong, YaJiang Zhu
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Patent number: 8482943Abstract: A power supply controller is provided for providing a drive current to a control terminal of a power transistor in three time intervals. The controller includes control circuits configured to control the drive current in multiple stages. During a first time interval, first drive current includes a current spike for turning on the power transistor in response to a start of the control signal pulse. During a second time interval, a second drive current includes a ramping current substantially proportional to a magnitude of a current through the power transistor. During a third time interval, current flow to the power transistor is at least partially turned off before an end of the control signal pulse.Type: GrantFiled: December 15, 2009Date of Patent: July 9, 2013Assignee: BCD Semiconductor Manufacturing LimitedInventors: Jianhua Duan, Qiang Zong, Yajiang Zhu
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Publication number: 20110261596Abstract: A switched mode power supply (SMPS) includes a transformer with a primary winding, a secondary winding, an auxiliary winding, and a power switch coupled to the primary winding. During one switching cycle, the auxiliary winding provides a feedback signal which includes a first voltage pulse that is induced after the power switch is turned on and a second voltage pulse that is induced after the power switch is turned off. A control circuit includes a circuit for generating a sampling signal for sampling the second voltage pulse in a switching cycle at a time that is determined based on the first voltage pulse in the same switching cycle. A sample-and-hold circuit is configured for sampling and storing the second voltage pulse in response to the sampling signal. A switching signal generating circuit is configured to generate a switching signal for controlling the power switch based on an output of the sample-and-hold circuit.Type: ApplicationFiled: April 20, 2011Publication date: October 27, 2011Applicant: BCD Semiconductor Manufacturing LimitedInventors: Qiang Zong, Huizhen Zhu, Pingan Zhao, Yajiang Zhu
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Publication number: 20110122659Abstract: A power supply controller is provided for providing a drive current to a control terminal of a power transistor in three time intervals. The controller includes control circuits configured to control the drive current in multiple stages. During a first time interval, first drive current includes a current spike for turning on the power transistor in response to a start of the control signal pulse. During a second time interval, a second drive current includes a ramping current substantially proportional to a magnitude of a current through the power transistor. During a third time interval, current flow to the power transistor is at least partially turned off before an end of the control signal pulse.Type: ApplicationFiled: December 15, 2009Publication date: May 26, 2011Applicant: BCD Semiconductor Manufacturing LimitedInventors: Jianhua Duan, Qiang Zong, YaJiang Zhu
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Publication number: 20110116289Abstract: A startup circuit for a switching-mode power supply (SMPS) includes a first voltage detector configured to trigger the switching-mode power supply from a first operation mode to a second operation mode when an input supply voltage exceeds a first threshold voltage, a current consumption in the first voltage detector in the first operation mode being determined by a reverse leakage current of a diode. A feedback circuit is coupled to the first voltage detector and being capable of maintaining a positive feedback loop. A second voltage detector is coupled to the first voltage detector and the feedback circuit, and is configured to trigger the switching-mode power supply to switch from the second operation mode to the first operation mode when the input supply voltage is below a second threshold voltage.Type: ApplicationFiled: January 27, 2011Publication date: May 19, 2011Applicant: BCD Semiconductor Manufacturing LimitedInventors: Qiang Zong, Shaohua Fang, Reixia Fei, Jia Xie
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Publication number: 20110096578Abstract: A synchronous rectification circuit for a power converter includes a power switch coupled to a transformer and an output capacitor and a switching control circuit configured to provide a control signal to the power switch in response to a first state and a second state of the voltage across the power switch. In the switching control circuit, the second state is determined prior to the first state is determined. In an embodiment, the switching control circuit includes a voltage comparing unit configured to act in response to the first and second inputs. The voltage comparing unit is also configured to output a logic signal according to the voltage difference between the sensed voltage drop across the power switch and a reference threshold voltage. A logic processing circuit is coupled to the voltage comparing unit and configured to provide the first state and the second state of the voltage across the power switch.Type: ApplicationFiled: October 22, 2009Publication date: April 28, 2011Applicant: BCD Semiconductor Manufacturing LimitedInventors: ShaoHua Fang, BaoZhen Chen, Qiang Zong, YaJiang Zhu
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Patent number: 7894219Abstract: A startup circuit for a switching-mode power supply (SMPS) includes a first voltage detector configured to trigger the switching-mode power supply from a startup mode to a normal operation mode when an input supply voltage exceeds a first threshold voltage, a current consumption in the first voltage detector in the startup mode being determined by a reverse leakage current of a diode. A feedback circuit is coupled to the first voltage detector and being capable of maintaining a positive feedback loop with a current consumption of no more than a microampere. A second voltage detector is coupled to the first voltage detector and the feedback circuit, and is configured to trigger the switching-mode power supply to switch from the normal operation mode to the startup mode when the input supply voltage is below a second threshold voltage.Type: GrantFiled: May 14, 2009Date of Patent: February 22, 2011Assignee: BCD Semiconductor Manufacturing LimitedInventors: Qiang Zong, Shaohua Fang, Reixia Fei, Jia Xie
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Publication number: 20100244804Abstract: A startup circuit for a switching-mode power supply (SMPS) includes a first voltage detector configured to trigger the switching-mode power supply from a startup mode to a normal operation mode when an input supply voltage exceeds a first threshold voltage, a current consumption in the first voltage detector in the startup mode being determined by a reverse leakage current of a diode. A feedback circuit is coupled to the first voltage detector and being capable of maintaining a positive feedback loop with a current consumption of no more than a microampere. A second voltage detector is coupled to the first voltage detector and the feedback circuit, and is configured to trigger the switching-mode power supply to switch from the normal operation mode to the startup mode when the input supply voltage is below a second threshold voltage.Type: ApplicationFiled: May 14, 2009Publication date: September 30, 2010Applicant: BCD Semiconductor Manufacturing LimitedInventors: Qiang Zong, Shaohua Fang, Reixia Fei, Jia Xie