Patents by Inventor En Li

En Li 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).

  • Publication number: 20130242626
    Abstract: A discharge circuit for an EMI filter capacitor, wherein the EMI filter capacitor is coupled between input terminals of a switching converter. The discharge circuit has a detecting circuit and a current source. The detecting circuit is configured to detect whether an electrical source is coupled to the input terminals of the switching converter. The current source is coupled between the input terminals of the switching converter and a power supply capacitor, and is configured to provide a power supply voltage across the power supply capacitor. When the electrical source is uncoupled from the input terminals of the switching converter, the EMI filter capacitor is discharged by the current source.
    Type: Application
    Filed: March 11, 2013
    Publication date: September 19, 2013
    Applicant: CHENGDU MONOLITHIC POWER SYSTEMS CO., LTD.
    Inventor: En Li
  • Patent number: 8498135
    Abstract: Embodiments of circuits and methods for a switching mode power supply are described in detail herein. In one embodiment, a switching mode power supply includes a transformer having a primary winding and a secondary winding to supply power to a load, a feedback circuit that generates a feedback signal that varies in relation to the load on the secondary winding, a switching circuit coupled to the primary winding to control current flow through the primary winding, and a control circuit coupled to the switching circuit to control the on/off status of switching circuit in response to the feedback signal and the current flow through the primary winding. The control circuit comprises a spectrum shaping circuit configured to generate a spectrum shaping signal in response to the feedback signal. The spectrum shaping signal can then be used to regulate the switching frequency and the spectrum shaping range.
    Type: Grant
    Filed: November 11, 2010
    Date of Patent: July 30, 2013
    Assignee: Monolithic Power Systems, Inc.
    Inventors: En Li, Junming Zhang, Yuancheng Ren
  • Patent number: 8472217
    Abstract: A switching mode power supply with a multi-mode controller is provided. The switching mode power supply may include a transformer having a primary winding and a secondary winding to supply power to a load. A feedback circuit may be included to generate a feedback signal that varies in relation to the load on the secondary winding. The multi-mode controller may include a switching circuit, a frequency control circuit and a current limiting circuit. The switching circuit may be coupled to the primary winding to control current flow through the primary winding. The frequency control circuit may control a switching frequency of the switching circuit based on the feedback signal. The current limiting circuit may limit current flow through the primary winding by causing the switching circuit to suspend current flow through the primary winding when the current reaches a peak current limit that is set based on the feedback signal.
    Type: Grant
    Filed: March 9, 2010
    Date of Patent: June 25, 2013
    Assignee: Monolithic Power Systems, Inc.
    Inventors: En Li, Junming Zhang, Yuancheng Ren
  • Publication number: 20130082742
    Abstract: A no-load detecting circuit and the method thereof are disclosed. The no-load detecting circuit may be applied in switching mode power supplies or other circuits. The no-load detecting circuit comprises: a variable resistance circuit coupled in series to a load of the switching mode power supply; and a first comparison circuit coupled to the variable resistance circuit to receive the voltage across the variable resistance circuit, wherein based on the comparison of the voltage across the variable resistance circuit and a first threshold, the first comparison circuit generates a no-load detecting signal indicative of the load status; wherein the equivalent resistance of the variable resistance circuit varies based on the varying of the load of the switching mode power supply.
    Type: Application
    Filed: June 29, 2012
    Publication date: April 4, 2013
    Applicant: Chengdu Monolithic Power Systems Co., Ltd.
    Inventors: Yuancheng Ren, En Li, Naixing Kuang, Yike Li
  • Patent number: 8391030
    Abstract: Switching mode power supplies and associated methods of control are disclosed herein. In one embodiment, a method for controlling a switching mode power supply includes determining whether the switching mode power supply is in a burst mode. If the switching mode power supply is in the burst mode, the method includes recording a switching time with and without switching pulses to obtain a current value of an equivalent frequency and generating a peak current limit that decreases as a load becomes lighter based on the equivalent frequency, thereby maintaining the equivalent frequency at the current value above an audible range. If the switching mode power supply is not in the burst mode, the method includes continuing to monitor whether the switching mode power supply is in the burst mode.
    Type: Grant
    Filed: August 31, 2010
    Date of Patent: March 5, 2013
    Assignee: Monolithic Power Systems, Inc.
    Inventors: En Li, Junming Zhang
  • Patent number: 8315072
    Abstract: A switching power supply has an inductor that includes a coil. A chopper circuit chops the primary current drawn through the coil, for the inductor to output an induced current. A multifunction junction of the power supply has a multifunction voltage that is a function of a primary voltage that drives the coil. A first circuit suspends the chopping in response to a first sensed voltage crossing a first threshold, the first sensed voltage being a function of the multifunction voltage. A second circuit suspends the chopping in response to a second sensed voltage crossing a second threshold, the second threshold being a function of the multifunction voltage.
    Type: Grant
    Filed: March 9, 2010
    Date of Patent: November 20, 2012
    Assignee: Monolithic Power Systems, Inc.
    Inventors: Huanyu Lu, En Li
  • Patent number: 8238124
    Abstract: Dual-mode AC/DC power converters and associated methods of operation are disclosed herein. In one embodiment, the AC/DC converter includes a primary winding, a switching transistor coupled to the primary winding, the switching transistor configured to carry a drain-source current, and a feedback voltage port configured to carry a feedback voltage. The feedback voltage port is coupled to the switching transistor to switch off the switching transistor when the drain-source current reaches a peak current limit. The peak current limit increases with increasing feedback voltage if and only if the feedback voltage satisfies an ordered relationship with a threshold.
    Type: Grant
    Filed: December 9, 2009
    Date of Patent: August 7, 2012
    Assignee: Monolithic Power Systems, Inc.
    Inventors: Huanyu Lu, En Li
  • Publication number: 20120162765
    Abstract: The present invention provides an optical device having inhomogeneous polarization selectivity. The optical device includes a transparent substrate having a surface, a first optical element and a second optical element. The first and the second elements are disposed on the surface. The first optical element has a first polarization selectivity at least within a full visible frequency domain. The second optical element has a second polarization selectivity at least within a full visible frequency domain. The first and the second polarization selectivities have different orientations.
    Type: Application
    Filed: June 27, 2011
    Publication date: June 28, 2012
    Applicant: National Chiao Tung University
    Inventors: Chung-Hao Tien, Tzu-Hsiang Lan, Jie-En Li
  • Publication number: 20120112795
    Abstract: A switching mode power supply with improved peak current control is disclosed. A varying reference signal is adopted to limit the peak current in the energy storage component. The varying reference signal is an exponential function of a time period when a power switch is ON, wherein the power switch is coupled to the energy storage component. The varying reference signal may be generated by a circuit comprising a RC circuit and one or several voltage sources.
    Type: Application
    Filed: November 3, 2011
    Publication date: May 10, 2012
    Inventors: Siran Wang, Yuancheng Ren, Junming Zhang, En Li
  • Publication number: 20120113684
    Abstract: A compensation circuit and method for constant current regulation of switching mode power supply are disclosed. The ringing waveform of a feedback signal, indicative of the output current of the power supply, causes error. To eliminate the error, a current source charges a capacitor in response to a demagnetizing oscillation signal indicative of the error caused by the ringing waveform of the feedback signal. The voltage across the capacitor is compared to a reference signal to generate a more accurate signal indicative of the conductive time of a secondary diode in a secondary winding of the switching mode power supply. This more accurate signal is inputted to a logic circuit to generate a constant current control signal to control a power switch of the power supply.
    Type: Application
    Filed: November 4, 2011
    Publication date: May 10, 2012
    Inventors: Siran Wang, Yuancheng Ren, Junming Zhang, En Li
  • Patent number: 8132028
    Abstract: A motherboard and a power supply module thereof are disclosed. The power supply module provided by the invention can be directly fixed on a motherboard supporting an AM2 CPU and an AM2+ CPU. The power supply module provided by the invention utilizes a switching unit to switch between a group of pulse width modulation (PWM) signals for generating core voltages needed by an AM2 CPU and another PWM signal for generating a core voltage needed by an AM2+ CPU according to a version signal provided by the CPU of the motherboard. Therefore, no matter a CPU socket of the motherboard receives the AM2 CPU or the AM2+ CPU, the power supply module of the invention can obtain the maximum usage efficiency thereof, and the manufacture cost of motherboard with the power supply module decreases.
    Type: Grant
    Filed: June 9, 2008
    Date of Patent: March 6, 2012
    Assignee: ASUSTeK Computer Inc.
    Inventors: Jiang-Shin Wu, En-Li Chen
  • Publication number: 20120049822
    Abstract: A frequency limitation method used in a quasi-resonant controlled switching regulator is disclosed. The switching frequency is limited by setting a minimum time period, such as a minimum switching period or a minimum OFF time period. The minimum time period is varying according to the difference between the minimum time period of the previous cycle and an offset value, so as to eliminate the audible noise caused by the frequency hopping when the minimum OFF time period is close to the valley of a quasi-resonant signal.
    Type: Application
    Filed: August 25, 2011
    Publication date: March 1, 2012
    Inventors: Yike Li, Rui Wang, En Li
  • Publication number: 20120029699
    Abstract: A method for robot trajectory generation with continuous acceleration, Receiving a user's motion command through a motion command interface, and sending the user's motion command to Cartesian trajectory generator; Converting the user's command to a trajectory path points of robot end effector in Cartesian space; Transforming the trajectory path points of robot end effector in Cartesian space into a robot trajectory path points in a joint space; Calculating positions, velocities and accelerations of robot joints in each motion servo cycle; Comparing the positions, velocities and accelerations of the robot joints generated by a joint Trajectory Interpolator with a velocity's limit value and an acceleration's limit value of each robot joint stored in a robot parameter database respectively.
    Type: Application
    Filed: June 4, 2010
    Publication date: February 2, 2012
    Applicant: Institute of Automation, Chinese Academy of Sciences
    Inventors: Fengshui Jing, Min Tan, En Li, Zize Liang, Zengguang Hou, Degang Yang, Kailiang Zhang, Yanhui Qiang
  • Patent number: 8033014
    Abstract: The present invention provides a method of making a molded interconnect device. The method includes the steps of: injection molding a plastic body having thereon at least one patterned circuit trench structure; and filling a conductive material into the patterned circuit trench structure thereby forming a circuit trace on the plastic body.
    Type: Grant
    Filed: July 7, 2008
    Date of Patent: October 11, 2011
    Assignee: Unimicron Technology Corp.
    Inventors: Cheng-Hung Yu, Chi-En Li
  • Publication number: 20110228570
    Abstract: Switching mode power supplies with primary side control and associated methods of control are disclosed. In one embodiment, a signal with input voltage information and a signal with both input voltage information and output voltage information are provided to a subtracter to generate a feedback signal that is indicative of the output voltage. The feedback signal is then used to control the switching mode power supply.
    Type: Application
    Filed: March 15, 2011
    Publication date: September 22, 2011
    Inventors: En Li, Junming Zhang, Yuancheng Ren
  • Publication number: 20110112912
    Abstract: A web-based classified ads system providing tools that enable buyers and sellers to complete transactions in a social network environment. By integrating many of the transactions features such as classifieds, auctioning, bartering, event signups, with social networking elements such as profiles, chats, friend lists, groups, messages, degrees of separations, friend post notifications, feedbacks, and recommendations the system of the present invention reduces anxiety and cuts down on time and cost involved in business transactions.
    Type: Application
    Filed: November 11, 2009
    Publication date: May 12, 2011
    Inventor: En-li Wu
  • Publication number: 20110110123
    Abstract: Embodiments of circuits and methods for a switching mode power supply are described in detail herein. In one embodiment, a switching mode power supply includes a transformer having a primary winding and a secondary winding to supply power to a load, a feedback circuit that generates a feedback signal that varies in relation to the load on the secondary winding, a switching circuit coupled to the primary winding to control current flow through the primary winding, and a control circuit coupled to the switching circuit to control the on/off status of switching circuit in response to the feedback signal and the current flow through the primary winding. The control circuit comprises a spectrum shaping circuit configured to generate a spectrum shaping signal in response to the feedback signal. The spectrum shaping signal can then be used to regulate the switching frequency and the spectrum shaping range.
    Type: Application
    Filed: November 11, 2010
    Publication date: May 12, 2011
    Inventors: En Li, Junming Zhang, Yuancheng Ren
  • Publication number: 20110051470
    Abstract: Switching mode power supplies and associated methods of control are disclosed herein. In one embodiment, a method for controlling a switching mode power supply includes determining whether the switching mode power supply is in a burst mode. If the switching mode power supply is in the burst mode, the method includes recording a switching time with and without switching pulses to obtain a current value of an equivalent frequency and generating a peak current limit that decreases as a load becomes lighter based on the equivalent frequency, thereby maintaining the equivalent frequency at the current value above an audible range. If the switching mode power supply is not in the burst mode, the method includes continuing to monitor whether the switching mode power supply is in the burst mode.
    Type: Application
    Filed: August 31, 2010
    Publication date: March 3, 2011
    Inventors: EN LI, JUNMING ZHANG
  • Publication number: 20100302813
    Abstract: Dual-mode AC/DC power converters and associated methods of operation are disclosed herein. In one embodiment, the AC/DC converter includes a primary winding, a switching transistor coupled to the primary winding, the switching transistor configured to carry a drain-source current, and a feedback voltage port configured to carry a feedback voltage. The feedback voltage port is coupled to the switching transistor to switch off the switching transistor when the drain-source current reaches a peak current limit. The peak current limit increases with increasing feedback voltage if and only if the feedback voltage satisfies an ordered relationship with a threshold.
    Type: Application
    Filed: December 9, 2009
    Publication date: December 2, 2010
    Inventors: Huanyu Lu, En Li
  • Publication number: 20100302814
    Abstract: A switching power supply has an inductor that includes a coil. A chopper circuit chops the primary current drawn through the coil, for the inductor to output an induced current. A multifunction junction of the power supply has a multifunction voltage that is a function of a primary voltage that drives the coil. A first circuit suspends the chopping in response to a first sensed voltage crossing a first threshold, the first sensed voltage being a function of the multifunction voltage. A second circuit suspends the chopping in response to a second sensed voltage crossing a second threshold, the second threshold being a function of the multifunction voltage.
    Type: Application
    Filed: March 9, 2010
    Publication date: December 2, 2010
    Inventors: Huanyu Lu, En Li