Patents Assigned to Alpha and Omega Semiconductor (Cayman) LTD
  • Patent number: 9548667
    Abstract: The present invention discloses a constant on-time isolated converter comprising a transformer with a primary side and a secondary side. The primary side is connected to an electronic switch and secondary-side is connected to a load and a processor. The processor is connected to a driver on primary side through at least one coupling element and to the electronic switch. The processor receives an output voltage or an output current across the load generating a control signal accordingly. The driver receives the control signal through the coupling element and accordingly changes the ON/OFF state of the electronic switch, regulating the output voltage and the output current via the transformer, where the duration of the ON/OFF state of the electronic switch is determined between the moment control signal changes from negative to positive and the moment it changes from positive to negative to achieve a high-speed load transient response.
    Type: Grant
    Filed: December 7, 2014
    Date of Patent: January 17, 2017
    Assignee: Alpha and Omega Semiconductor (Cayman) Ltd.
    Inventors: Tien-Chi Lin, Chih-Yuan Liu, Yung-Chuan Hsu, Pei-Lun Huang
  • Publication number: 20160358705
    Abstract: A voltage converter comprises a second controller as a power switch of the secondary side of the transformer for comparing a detection voltage representing an output voltage and/or load current with a first reference voltage and generating a control signal, and a coupling element for transmitting the control signal generated by the second controller to the first controller on the primary side of the transformer enabling the first controller to generate a first pulse signal driving the power switch to control the on/off state of the primary side winding.
    Type: Application
    Filed: August 18, 2016
    Publication date: December 8, 2016
    Applicant: Alpha and Omega Semiconductor (Cayman) Ltd.
    Inventors: Tien-Chi Lin, Yu-Ming Chen, Jung-Pei Cheng, Pei-Lun Huang
  • Publication number: 20160359421
    Abstract: The present invention relates to a power supply device for voltage converter, which includes a master switch, a first controller for generating a first pulse signal to drive the master switch to be turned on and turned off, a second controller for comparing a detection voltage representing an output voltage and/or load current with a first reference voltage to determine the logic state of a control signal generated by the second controller, and a coupling element connected between the first controller and the second controller for transmitting the logic state of the control signal to the first controller and enabling the first controller to determine the logic state of the first pulse signal according to the logic state of the control signal. The second controller includes a driving module for generating a second control signal to drive a synchronous switch to be turned on and turned off.
    Type: Application
    Filed: August 18, 2016
    Publication date: December 8, 2016
    Applicant: Alpha and Omega Semiconductor (Cayman) Ltd.
    Inventors: Tien-Chi Lin, Yu-Ming Chen, Jung-Pei Cheng, Yung-Chuan Hsu, Yueh-Ping Yu, Wei-Ting Wang, Pei-Lun Huang
  • Publication number: 20160359419
    Abstract: A voltage converter comprises a second controller as a power switch of the secondary side of the transformer for comparing a detection voltage representing an output voltage and/or load current with a first reference voltage and generating a control signal, and a coupling element for transmitting the control signal generated by the second controller to the first controller on the primary side of the transformer enabling the first controller to generate a first pulse signal driving the power switch to control the on/off state of the primary side winding.
    Type: Application
    Filed: August 18, 2016
    Publication date: December 8, 2016
    Applicant: Alpha and Omega Semiconductor (Cayman) Ltd.
    Inventors: Tien-Chi Lin, Yu-Ming Chen, Jung-Pei Cheng, Yung-Chuan Hsu, Yueh-Ping Yu, Wei-Ting Wang, Pei-Lun Huang
  • Patent number: 9490712
    Abstract: An output current calculating circuit for a flyback converter operating under CCM and DCM is disclosed. The off current value ION and the blanking current value ILEB flowing through a sensing resistor are calculated using a detection module and are summed together using a current summing unit. A voltage converted from the sum value of the off current value IOFF and the blanking current value ILEB is transmitted through an output stage in a predetermined time ratio of a cycle with the duty cycle determined by a logic control unit, in which the logic control unit controls the output stage to receive the voltage converted from sum current in a predetermined time period of each cycle, and prevents the output stage to receive the voltage converted from sum current in the remaining time other than such predetermined time period of each cycle.
    Type: Grant
    Filed: June 30, 2015
    Date of Patent: November 8, 2016
    Assignee: Alpha and Omega Semiconductor (Cayman) Ltd.
    Inventors: Yu-Ming Chen, Jung-Pei Cheng, Pei-Lun Huang
  • Patent number: 9437528
    Abstract: A dual-side exposed semiconductor package with ultra-thin die and a manufacturing method are disclosed. A die having a source electrode and a gate electrode at top surface is flipped and attached to a die paddle of a lead frame and then is encapsulated with a first molding compound. The first molding compound and the die are ground to reduce the thickness. A mask is applied atop the lead frame with the back of the flipped die exposed and a metal layer is deposited on the exposed area at the back of the flipped die. A metal clip is attached to the back of the flipped die. A second molding compound is deposited on the lead frame with the top surface of the metal clip exposed from the top surface of the second molding compound and the bottom surface of the lead frame exposed from the bottom surface of the second plastic molding compound.
    Type: Grant
    Filed: September 22, 2015
    Date of Patent: September 6, 2016
    Assignee: ALPHA AND OMEGA SEMICONDUCTOR (CAYMAN) LTD.
    Inventors: Yuping Gong, Xiaoming Sui, Yan Yun Xue, Jun Lu
  • Patent number: 9385530
    Abstract: An input line selector system provided to selectively connect one of two input power lines is configured with a single switch provided in series with each of the input power lines, the connection between the switches being made such that it prevents reverse flow of current in the event that the switches are OFF. A smart, simple and precisely operating automatic line selector is provided to control the operation of the two switches. The line selector system configuration is simple and implements only two switches and can be applied to a linear charger or switching charger application with addition of one or two switches respectively, thereby providing a simple, efficient and cost effective system.
    Type: Grant
    Filed: December 12, 2012
    Date of Patent: July 5, 2016
    Assignee: Alpha and Omega Semiconductor (Cayman), Ltd.
    Inventor: Gilbert S. Lee
  • Patent number: 9337127
    Abstract: A small and ultra-thin power semiconductor device and a preparation method are disclosed. The device includes a chip mounting unit with a plurality of pads with a plate arranged on top surface of each pad; a semiconductor chip flipped and attached on the chip mounting unit, where the electrodes at the front of the chip are electrically connected to the pads; a plastic packaging body covering the chip mounting units and the chip, where the top surface of the plate and the back surface of the chip are exposed out from top surface of the plastic packaging body and the bottom surfaces of the pads are exposed out of the bottom surface of the plastic packaging body; a plurality of top metal segments arranged on the top surface of the plastic packaging body and electrically connected to the top surface of each plate and the back surface of the chip.
    Type: Grant
    Filed: July 21, 2015
    Date of Patent: May 10, 2016
    Assignee: Alpha and Omega Semiconductor (Cayman) Ltd.
    Inventor: Yan Huo
  • Patent number: 9337131
    Abstract: An ultrathin power semiconductor package with high thermal dissipation performance and its preparation method are disclosed. The package includes a lead frame unit with a staggered structure including an upper section and a lower section. A thin layer is attached on the surface of the lead frame unit having a plurality of contact holes on the upper section and at least one opening on the lower section. A semiconductor chip is attached on the opening on the lower section of the lead frame unit and then a plurality of metal bumps are deposited, where one metal bump is formed on each contact hole on the upper section and on each of the electrodes on the top surface of the semiconductor chip.
    Type: Grant
    Filed: September 29, 2014
    Date of Patent: May 10, 2016
    Assignee: Alpha and Omega Semiconductor (Cayman) Ltd.
    Inventors: Yan Huo, Hamza Yilmaz, Jun Lu, Ming-Chen Lu, Zhi Qiang Niu, Yan Xun Xue, Demei Gong
  • Patent number: 9245831
    Abstract: A semiconductor package includes a lead frame having a die paddle and a plurality of leads connected to die paddle, where each lead has a lead surface parallel to die paddle and is a continuous extension bending upward from die paddle. A semiconductor chip is mounted on die paddle, where drain metal layer covering a first surface of chip is connected to die paddle, and source metal layer and gate metal layer are located on a second surface opposite to first surface with gate metal layer located at one corner of the second surface. A source metal plate and a gate metal plate are attached on source metal layer and gate metal layer respectively. A molding layer covers lead frame, semiconductor chip, source metal plate and gate metal plate, where lead surface, top surfaces of source metal plate and gate metal plate are exposed from top surface of molding layer.
    Type: Grant
    Filed: November 5, 2014
    Date of Patent: January 26, 2016
    Assignee: ALPHA AND OMEGA SEMICONDUCTOR (CAYMAN) LTD.
    Inventors: Yan Huo, Zhi Qiang Niu, Ming-Chen Lu, Hongtao Gao
  • Publication number: 20150372595
    Abstract: The present invention discloses a voltage control method. At first, the load voltage of the load is divided to generate a feedback voltage. The feedback voltage and a triangular wave of a triangular wave periodic signal, including the positive voltage and negative voltage, are combined to generate a sum signal. The sum signal is compared with a target voltage, and when the sum signal is less than the target voltage signal, a control signal is generated to control the switches to turn on or off. Finally, the switch receives the control signal and accordingly providing an input voltage to update and stabilize the load voltage.
    Type: Application
    Filed: August 27, 2015
    Publication date: December 24, 2015
    Applicant: ALPHA AND OMEGA SEMICONDUCTOR (CAYMAN) LTD.
    Inventors: Kong Soon Ng, Wei-Chi Huang, Jean-Shin Wu
  • Publication number: 20150357268
    Abstract: A power semiconductor package with a small footprint and a preparation method thereof are disclosed. The first semiconductor chip and second semiconductor chip are attached on the front and back sides of a die paddle. Conductive pads are then attached on the electrodes at the top surfaces of the first and second semiconductor chips flowed by the formation of a plastic package body covering the die paddle, first and second semiconductor chips, the conductive pads, where a side surface of a conductive pad is exposed from a side surface of the plastic package body.
    Type: Application
    Filed: June 7, 2014
    Publication date: December 10, 2015
    Applicant: Alpha and Omega Semiconductor (Cayman), Ltd
    Inventors: Hongtao Gao, Jun Lu, Ming-Chen Lu, Jianxin Ye, Yan Huo, Hua Pan
  • Publication number: 20150325500
    Abstract: A small and ultra-thin power semiconductor device and a preparation method are disclosed. The device includes a chip mounting unit with a plurality of pads with a plate arranged on top surface of each pad; a semiconductor chip flipped and attached on the chip mounting unit, where the electrodes at the front of the chip are electrically connected to the pads; a plastic packaging body covering the chip mounting units and the chip, where the top surface of the plate and the back surface of the chip are exposed out from top surface of the plastic packaging body and the bottom surfaces of the pads are exposed out of the bottom surface of the plastic packaging body; a plurality of top metal segments arranged on the top surface of the plastic packaging body and electrically connected to the top surface of each plate and the back surface of the chip.
    Type: Application
    Filed: July 21, 2015
    Publication date: November 12, 2015
    Applicant: Alpha and Omega Semiconductor (Cayman) Ltd.
    Inventor: Yan - Huo
  • Patent number: 9154034
    Abstract: The present invention discloses a voltage control method. At first, the load voltage of the load is divided to generate a feedback voltage. The feedback voltage and a triangular wave of a triangular wave periodic signal, including the positive voltage and negative voltage, are combined to generate a sum signal. The sum signal is compared with a target voltage, and when the sum signal is less than the target voltage signal, a control signal is generated to control the switches to turn on or off. Finally, the switch receives the control signal and accordingly providing an input voltage to update and stabilize the load voltage.
    Type: Grant
    Filed: August 13, 2014
    Date of Patent: October 6, 2015
    Assignee: Alpha and Omega Semiconductor (Cayman), Ltd.
    Inventors: Kong Soon Ng, Wei-Chi Huang, Jean-Shin Wu
  • Patent number: 9118322
    Abstract: A bidirectional switch device includes a main pass field effect transistor (FET) connected to an input node and an output node. A body region of the first main pass transistor is tied to a voltage substantially halfway between the voltage at the input node side of the first main pass transistor and the voltage at the output node side of the transistor when the first main pass transistor is in an ON state.
    Type: Grant
    Filed: February 24, 2011
    Date of Patent: August 25, 2015
    Assignee: Alpha and Omega Semiconductor (Cayman) LTD
    Inventors: Mohammad Suhaib Husain, Shekar Mallikarjunaswamy
  • Patent number: 9117809
    Abstract: A preparation method of small and ultra-thin power semiconductor device comprising the steps of: providing a chip mounting unit with a plurality of pads with a plate arranged on top surface of each pad; flipping and attaching a semiconductor chip on the chip mounting unit, where the electrodes at the front of the chip are electrically connected to the pads; forming a plastic packaging body covering the chip mounting units and the chip, where the top surface of the plate and the back surface of the chip are exposed out from top surface of the plastic packaging body and the bottom surfaces of the pads are exposed out of the bottom surface of the plastic packaging body; forming a plurality of top metal segments arranged on the top surface of the plastic packaging body and electrically connected to the top surface of each plate and the back surface of the chip.
    Type: Grant
    Filed: March 9, 2014
    Date of Patent: August 25, 2015
    Assignee: Alpha & Omega Semiconductor (Cayman), Ltd.
    Inventor: Yan Huo