Patents by Inventor Gwan-Bon Koo

Gwan-Bon Koo 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).

  • Patent number: 10407113
    Abstract: An LED driver is provided. The LED driver comprises a plurality of driving units and a fold circuit. The driving units are coupled to an LED string including a plurality of LEDs for driving the LEDs. The fold circuit is coupled to the LED string and divides the LED string into a plurality of LED segments when an input voltage is lower than a threshold voltage. The LED segments are coupled to each other in parallel, and the input voltage is supplied to the LED segments.
    Type: Grant
    Filed: November 14, 2016
    Date of Patent: September 10, 2019
    Assignee: SEMICONDUCTOR COMPONENTS INDUSTRIES, LLC
    Inventors: Chen-Hua Chiu, Moon-Ho Choi, Gwan-Bon Koo
  • Patent number: 9917518
    Abstract: A method and a circuit of detecting attachment and detachment between a portable device and a power converter are provided. The method and the circuit confirm attachment of the portable device to the power converter and generate an attachment signal. The method and the circuit further detect a bus voltage of the power converter for confirming detachment of the portable device from the power converter.
    Type: Grant
    Filed: April 22, 2015
    Date of Patent: March 13, 2018
    Assignee: SEMICONDUCTOR COMPONENTS INDUSTRIES, LLC
    Inventors: Eui-Soo Kim, Bong-Geun Chung, Gwan-Bon Koo, Ju-Hyun Kim, Young-Bae Park
  • Patent number: 9814105
    Abstract: A control circuit for LED and an active bleeder thereof are provided. The control circuit comprises an LED driver and the active bleeder. The LED driver drives at least one LED and generates a current-sense signal. The current-sense signal is correlated to an LED current. The active bleeder comprises a bleeder circuit. The bleeder circuit is coupled to the LED driver to receive the current-sense signal and sinks a bleeding current in accordance with the current-sense signal for keeping the current flowing through the dimmer higher than the holding current.
    Type: Grant
    Filed: November 10, 2016
    Date of Patent: November 7, 2017
    Assignee: SEMICONDUCTOR COMPONENTS INDUSTRIES, LLC
    Inventors: Chen-Hua Chiu, Moon-Ho Choi, Gwan-Bon Koo
  • Publication number: 20170142798
    Abstract: An LED driver is provided. The LED driver comprises a plurality of driving units and a fold circuit. The driving units are coupled to an LED string including a plurality of LEDs for driving the LEDs. The fold circuit is coupled to the LED string and divides the LED string into a plurality of LED segments when an input voltage is lower than a threshold voltage. The LED segments are coupled to each other in parallel, and the input voltage is supplied to the LED segments.
    Type: Application
    Filed: November 14, 2016
    Publication date: May 18, 2017
    Inventors: CHEN-HUA CHIU, MOON-HO CHOI, GWAN-BON KOO
  • Publication number: 20170142797
    Abstract: A control circuit for LED and an active bleeder thereof are provided. The control circuit comprises an LED driver and the active bleeder. The LED driver drives at least one LED and generates a current-sense signal. The current-sense signal is correlated to an LED current. The active bleeder comprises a bleeder circuit. The bleeder circuit is coupled to the LED driver to receive the current-sense signal and sinks a bleeding current in accordance with the current-sense signal for keeping the current flowing through the dimmer higher than the holding current.
    Type: Application
    Filed: November 10, 2016
    Publication date: May 18, 2017
    Inventors: CHEN-HUA CHIU, MOON-HO CHOI, GWAN-BON KOO
  • Patent number: 9397284
    Abstract: The present invention relates to a piezoelectric circuit, a piezoelectric driving circuit driving the piezoelectric circuit, and a method for driving the piezoelectric circuit. The piezoelectric circuit includes a sub-piezoelectric circuit and an external inductor coupled in parallel with the sub-piezoelectric circuit. The external inductor discharges the sub-piezoelectric circuit when a polarity of a piezoelectric voltage, that is, a both-end voltage of the piezoelectric circuit is inverted. The piezoelectric driving circuit includes first and third switches connected to a first node of the piezoelectric circuit and second and fourth switches connected to a second node of the piezoelectric circuit.
    Type: Grant
    Filed: May 7, 2013
    Date of Patent: July 19, 2016
    Assignee: Fairchild Korea Semiconductor LTD
    Inventors: Gwan-Bon Koo, Young Sik Lee, Young-Bae Park
  • Publication number: 20150311806
    Abstract: A method and a circuit of detecting attachment and detachment between a portable device and a power converter are provided. The method and the circuit confirm attachment of the portable device to the power converter and generate an attachment signal. The method and the circuit further detect a bus voltage of the power converter for confirming detachment of the portable device from the power converter.
    Type: Application
    Filed: April 22, 2015
    Publication date: October 29, 2015
    Inventors: EUI-SOO KIM, BONG-GEUN CHUNG, GWAN-BON KOO, JU-HYUN KIM, YOUNG-BAE PARK
  • Patent number: 8981659
    Abstract: An input voltage transfer apparatus for an LED lighting system is provided. The input voltage transfer apparatus includes a source voltage storage unit, a zero voltage switching unit, and a nonzero voltage switching unit. The source voltage storage unit stores a source voltage. The zero voltage switching unit turns on according to the source voltage stored in the source voltage storage unit when a zero voltage is inputted. The nonzero voltage switching unit turns on according to a current applied thereto through the zero voltage switching unit when a nonzero voltage is inputted. When the nonzero voltage switching unit is turned on, the source voltage storage unit discharges the stored source voltage.
    Type: Grant
    Filed: October 10, 2011
    Date of Patent: March 17, 2015
    Assignee: LG Innotek Co., Ltd.
    Inventors: Young Jong Kim, Sang Hyun Park, Sang Man Kim, Woo Chang Jung, Gwan Bon Koo, Dong Young Huh, Seok Yoon
  • Patent number: 8878593
    Abstract: The present invention relates to a switch control circuit that controls a switching operation of a power switch circuit that includes cascode-coupled first and second transistors. A switch control circuit includes a first zener diode coupled between a gate of the first transistor and a first end of a capacitor supplying a power voltage and a second zener diode coupled to a gate and a source of the first transistor, and a first resistor coupled between the first zener diode and the second zener diode.
    Type: Grant
    Filed: October 25, 2013
    Date of Patent: November 4, 2014
    Assignee: Fairchild Korea Semiconductor Ltd.
    Inventors: Gwan-Bon Koo, Jin-Tae Kim, Won-Seok Lim
  • Publication number: 20140217925
    Abstract: An input voltage transfer apparatus for an LED lighting system is provided. The input voltage transfer apparatus includes a source voltage storage unit, a zero voltage switching unit, and a nonzero voltage switching unit. The source voltage storage unit stores a source voltage. The zero voltage switching unit turns on according to the source voltage stored in the source voltage storage unit when a zero voltage is inputted. The nonzero voltage switching unit turns on according to a current applied thereto through the zero voltage switching unit when a nonzero voltage is inputted. When the nonzero voltage switching unit is turned on, the source voltage storage unit discharges the stored source voltage.
    Type: Application
    Filed: October 10, 2011
    Publication date: August 7, 2014
    Applicant: LG INNOTEK CO., LTD.
    Inventors: Young Jong Kim, Sang Hyun Park, Sang Man Kim, Woo Chang Jung, Gwan Bon Koo, Dong Young Huh, Seok Yoon
  • Publication number: 20140118054
    Abstract: The present invention relates to a switch control circuit that controls a switching operation of a power switch circuit that includes cascode-coupled first and second transistors. A switch control circuit includes a first zener diode coupled between a gate of the first transistor and a first end of a capacitor supplying a power voltage and a second zener diode coupled to a gate and a source of the first transistor, and a first resistor coupled between the first zener diode and the second zener diode.
    Type: Application
    Filed: October 25, 2013
    Publication date: May 1, 2014
    Applicant: FAIRCHILD KOREA SEMICONDUCTOR LTD.
    Inventors: Gwan-Bon KOO, Jin-Tae KIM, Won-Seok LIM
  • Patent number: 8711581
    Abstract: A synchronous rectifier network unit and synchronous rectifying method. The synchronous rectifier network unit includes a first body diode to which a first current flows at a first time when the first current flows to a first coil, and a first transistor which is turned on after the first body diode is conducted, and to which the first current flows, and it rectifies the first current by differently controlling the turn-off time of the first transistor according to the first current.
    Type: Grant
    Filed: January 29, 2009
    Date of Patent: April 29, 2014
    Assignee: Fairchild Korea Semiconductor Ltd.
    Inventors: Jin-Tae Kim, Gwan-Bon Koo, Jinho Choi
  • Patent number: 8686645
    Abstract: Disclosed is an LED protection circuit using a one-shot vibrator. The LED protection circuit includes an LED module; an LED load-open detection circuit for detecting a voltage applied to the LED module to vary a reference potential; a latch circuit for maintaining a latch state according to the reference potential of the LED load-open detection circuit; a current limit circuit for receiving an output signal from the latch circuit to output a first signal; an LED load connection detection circuit for varying the reference potential through the first signal to output a second signal; a trigger input circuit connected to the LED load connection detection circuit for outputting a third signal using the second signal; and a one-shot vibrator for outputting a fourth signal of a square waveform during a predetermined time when the third signal is input.
    Type: Grant
    Filed: October 26, 2012
    Date of Patent: April 1, 2014
    Assignee: LG Innotek Co., Ltd.
    Inventors: Gwan Bon Koo, Dong Keun Yoon, Jong Hyun Lee, Jin Woo Lee, Jae Beom Cho, Ji Woong Jo
  • Patent number: 8670252
    Abstract: Disclosed are a switch controller, a switch control method, a converter using the same, and a driving method thereof. A first voltage is generated by using a voltage that is input to an input terminal, and a soft start signal is generated by using the first voltage during a soft start duration. A switching operation is controlled by using the soft start signal during the soft start duration.
    Type: Grant
    Filed: April 3, 2012
    Date of Patent: March 11, 2014
    Assignee: Fairchild Korea Semiconductor, Ltd.
    Inventors: Jin-Tae Kim, Gwan-Bon Koo, Hang Seok Choi
  • Patent number: 8625308
    Abstract: A switched-mode power supply includes a soft-burst circuit to minimize or prevent distracting audible noise. The power supply includes a control circuit for controlling switching of an output transistor to deliver a regulated output voltage to a load. The control circuit adjusts the operating frequency of the power supply based on a control signal. The soft-burst circuit discharges a storage device to minimize or prevent audible noise when the control signal reaches a particular level.
    Type: Grant
    Filed: February 6, 2009
    Date of Patent: January 7, 2014
    Assignee: Fairchild Korea Semiconductor Ltd.
    Inventors: Jin-Tae Kim, Kwang-Il Lee, Gwan-Bon Koo
  • Publication number: 20130293064
    Abstract: The present invention relates to a piezoelectric circuit, a piezoelectric driving circuit driving the piezoelectric circuit, and a method for driving the piezoelectric circuit. The piezoelectric circuit includes a sub-piezoelectric circuit and an external inductor coupled in parallel with the sub-piezoelectric circuit. The external inductor discharges the sub-piezoelectric circuit when a polarity of a piezoelectric voltage, that is, a both-end voltage of the piezoelectric circuit is inverted. The piezoelectric driving circuit includes first and third switches connected to a first node of the piezoelectric circuit and second and fourth switches connected to a second node of the piezoelectric circuit.
    Type: Application
    Filed: May 7, 2013
    Publication date: November 7, 2013
    Applicant: FAIRCHILD KOREA SEMICONDUCTOR LTD.
    Inventors: Gwan-Bon KOO, Young Sik LEE, Young-Bae PARK
  • Patent number: 8482886
    Abstract: The present invention relates to a protection circuit, a resonance converter having the same, and a protection method thereof. A resonance converter having high-side and low-side switches senses a current flowing through the low-side switch and determines a zero voltage switching failure by using a width of a current flowing to a negative direction of the low-side switch.
    Type: Grant
    Filed: November 14, 2012
    Date of Patent: July 9, 2013
    Assignee: Fairchild Korea Semiconductor Ltd.
    Inventors: Gwan-Bon Koo, Hyun-Chul Eom, Jin-Tae Kim
  • Patent number: 8339815
    Abstract: Ripple of an input voltage is used to modulate a switching operation frequency of a switch mode power supply. A sensing voltage corresponding to the input voltage is received, a current ripple that is proportional to a difference between a peak value of the sensing voltage and the sensing voltage is generated, and a modulation control signal that is variable by the current ripple is generated. A switching frequency is modulated using an oscillator signal that is variable by the modulation control signal, and reduces the output voltage ripple.
    Type: Grant
    Filed: May 26, 2010
    Date of Patent: December 25, 2012
    Assignee: Fairchild Korea Semiconductor Ltd.
    Inventors: Kwang-Il Lee, Jin-Tae Kim, Gwan-Bon Koo
  • Patent number: 8335061
    Abstract: The present invention relates to a protection circuit, a resonance converter having the same, and a protection method thereof. A resonance converter having high-side and low-side switches senses a current flowing through the low-side switch and determines a zero voltage switching failure by using a width of a current flowing to a negative direction of the low-side switch.
    Type: Grant
    Filed: March 3, 2010
    Date of Patent: December 18, 2012
    Assignee: Fairchild Korea Semiconductor Ltd.
    Inventors: Gwan-Bon Koo, Hyun-Chul Eom, Jin-Tae Kim
  • Patent number: RE44228
    Abstract: A switching mode power supply includes a switching transistor, coupled to a primary coil at a primary side of a transformer for converting an input DC voltage, supplying power to a secondary and a tertiary coil at a secondary side of the transformer according to an operation of the switching transistor; a switching controller receiving a feedback voltage corresponding to a first voltage generated in the secondary coil and receiving a detection signal corresponding to a current of the switching transistor to generate a switching control signal for controlling the turn on/off of the switching transistor; and a feedback signal generator receiving the first voltage and the switching control signal to set a sampling period, and storing the first voltage, sampled with a last pulse of the first pulse string within the sampling period as a feedback voltage. The output voltage is thereby accurately detected without opto-couplers or shunt regulators.
    Type: Grant
    Filed: March 1, 2012
    Date of Patent: May 21, 2013
    Assignee: Fairchild Korea Semiconductor, Ltd.
    Inventors: Young-Bae Park, Gwan-Bon Koo