Patents by Inventor Leaf Chen

Leaf Chen 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: 20200244165
    Abstract: A switching device includes a first switch and a threshold voltage adjustment circuitry. The first switch is configured to be selectively turned on according to an enable signal, in order to connect a first pin to a second pin. The threshold voltage adjustment circuitry is configured to adjust a voltage level of a bulk terminal of the first switch according to the enable signal and a voltage provided from a power source. In response to the voltage being de-asserted, the threshold voltage adjustment circuitry is further configured to cut off a signal path between the bulk terminal and the power source.
    Type: Application
    Filed: October 24, 2019
    Publication date: July 30, 2020
    Inventors: Leaf CHEN, Ya-Hsuan SUNG, Li-Chen LIU
  • Publication number: 20200174961
    Abstract: The invention discloses a control circuit applied to a Universal Serial Bus (USB) which includes a first channel configuration pin and a second channel configuration pin. The control circuit includes: a first transistor having a first control terminal; a first resistor group coupled to the first channel configuration pin and the first transistor; a first Schottky diode having a first end and a second end, the first end being coupled to the first control terminal; a second transistor having a second control terminal; a second resistor group coupled to the second channel configuration pin and the second transistor; and a second Schottky diode having a third end and a fourth end, the third end being coupled to the second control terminal, and the fourth end being coupled to the second end of the first Schottky diode.
    Type: Application
    Filed: November 14, 2019
    Publication date: June 4, 2020
    Inventor: LEAF CHEN
  • Publication number: 20200125519
    Abstract: The present invention provides an interface circuit, wherein the interface circuit includes a switching circuit, an over-voltage detection circuit and a control signal generating circuit. In the operations of the interface circuit, the switching circuit is configured to receive an input signal from an input terminal, and selectively transmit the input signal to an internal circuit. The over-voltage detection circuit is configured to detect whether a voltage level of the input signal is greater than a threshold value, and accordingly generate at least one over-voltage signal. The control signal generating circuit is configured to generate a control signal according to said at least one over-voltage signal, to control the switching circuit to be in one of three or more states.
    Type: Application
    Filed: September 19, 2019
    Publication date: April 23, 2020
    Inventors: Jiun-Hung Pan, Leaf Chen
  • Publication number: 20200119729
    Abstract: A switch circuit includes: a switching device control circuit receiving a first voltage and a second voltage, a first Type-I switching device coupled to the switching device control circuit and a first control voltage, a first Type-II switch element coupled to the switch control circuit and the first Type-I switch element, and a second Type-II switch element coupled to the first Type-I switch element and the first Type-II switch element. When the second voltage is higher than the first voltage, the switch control circuit turns on the first Type-II switch element in order to turn off the second Type-II switch element; and when the second voltage is higher than the first voltage, the first Type-I switch element is off.
    Type: Application
    Filed: May 8, 2019
    Publication date: April 16, 2020
    Inventors: Ya-Hsuan Sung, Leaf Chen
  • Patent number: 10103722
    Abstract: A differential switch circuit includes: a first transistor having a first terminal coupled with a first input terminal, a second terminal coupled with a first output terminal, and a control terminal coupled with a switch signal receiving terminal; a second transistor having a first terminal coupled with a second input terminal, a second terminal coupled with a second output terminal, and a control terminal coupled with the switch signal receiving terminal; a central switch element positioned between the control terminals of the first and second transistors; and a switch element control circuit for controlling the central switch element based on a switch signal. When the switch signal turns on the first and second transistors, the switch element control circuit turns off the central switch element, and when the switch signal turns off the first and second transistors, the switch element control circuit turns on the central switch element.
    Type: Grant
    Filed: June 6, 2017
    Date of Patent: October 16, 2018
    Assignee: REALTEK SEMICONDUCTOR CORP.
    Inventors: Bo-Yu Chen, Leaf Chen
  • Patent number: 9882487
    Abstract: The present disclosure illustrates a voltage regulator having wide common voltage operating range and an operating method thereof. The voltage regulator can solve a problem of the prior art that the excessive low or high common voltage easily causes the voltage regulator to operate abnormally. In addition, the voltage regulator completes the operation of boosting voltage by increasing additional switch transistors and error amplifiers without using a complex design, so that the lower common voltage can still satisfy with the operation condition of the voltage regulator to output the correct output voltage accordingly.
    Type: Grant
    Filed: May 11, 2017
    Date of Patent: January 30, 2018
    Assignee: REALTEK SEMICONDUCTOR CORP.
    Inventor: Leaf Chen
  • Publication number: 20180006638
    Abstract: A differential switch circuit includes: a first transistor having a first terminal coupled with a first input terminal, a second terminal coupled with a first output terminal, and a control terminal coupled with a switch signal receiving terminal; a second transistor having a first terminal coupled with a second input terminal, a second terminal coupled with a second output terminal, and a control terminal coupled with the switch signal receiving terminal; a central switch element positioned between the control terminals of the first and second transistors; and a switch element control circuit for controlling the central switch element based on a switch signal. When the switch signal turns on the first and second transistors, the switch element control circuit turns off the central switch element, and when the switch signal turns off the first and second transistors, the switch element control circuit turns on the central switch element.
    Type: Application
    Filed: June 6, 2017
    Publication date: January 4, 2018
    Applicant: Realtek Semiconductor Corp.
    Inventors: Bo-Yu CHEN, Leaf CHEN
  • Publication number: 20170331375
    Abstract: The present disclosure illustrates a voltage regulator having wide common voltage operating range and an operating method thereof. The voltage regulator can solve a problem of the prior art that the excessive low or high common voltage easily causes the voltage regulator to operate abnormally. In addition, the voltage regulator completes the operation of boosting voltage by increasing additional switch transistors and error amplifiers without using a complex design, so that the lower common voltage can still satisfy with the operation condition of the voltage regulator to output the correct output voltage accordingly.
    Type: Application
    Filed: May 11, 2017
    Publication date: November 16, 2017
    Inventor: LEAF CHEN
  • Patent number: 9673800
    Abstract: An analog switch circuit is disclosed. The analog switch circuit includes a MOSFET and a control switch. The MOSFET includes a drain electrode, a source electrode, a gate electrode, and a body electrode. A gate bias is applied on the gate electrode to control whether the MOSFET is ON or OFF. The control switch includes a control terminal, a first terminal, a second terminal, and a third terminal. A control bias relating to the gate bias is applied to the control terminal so that the first terminal is connected to the second terminal when the MOSFET is ON, and the first terminal is connected to the third terminal when the MOSFET is OFF. The second terminal is connected to a first voltage source providing a first bias. The third terminal is connected to a second voltage source providing a second bias different from the first bias.
    Type: Grant
    Filed: February 19, 2016
    Date of Patent: June 6, 2017
    Assignee: REALTEK SEMICONDUCTOR CORP.
    Inventors: Guan-Yu Chen, Leaf Chen
  • Patent number: 9621158
    Abstract: A switch and a multiplexer including the same are provided, which are applicable to selectively transmit the high frequency signal from an input terminal to an output terminal therethrough. The switch includes a switch device and a variable resistor. The switch device is connected between the input terminal and the output terminal, and the switch device includes a control terminal and is configured to be switched between ON and OFF according to a switch controlling signal provided to the control terminal. The variable resistor is connected to the control terminal and configured to change to a first resistance while the switch device is ON, and to change to a second resistance while the switch device is OFF according to a resistor controlling signal. The first resistance is higher than the second resistance, and the resistor controlling signal is changed corresponding to the switch controlling signal.
    Type: Grant
    Filed: September 28, 2015
    Date of Patent: April 11, 2017
    Assignee: REALTEK SEMICONDUCTOR CORP.
    Inventors: Ming-Hui Tung, An-Ming Lee, Leaf Chen, Chien-Wen Chen, Guan-Yu Chen, Tsung-Yen Liu
  • Publication number: 20160301410
    Abstract: A switch and a multiplexer including the same are provided, which are applicable to selectively transmit the high frequency signal from an input terminal to an output terminal therethrough. The switch includes a switch device and a variable resistor. The switch device is connected between the input terminal and the output terminal, and the switch device includes a control terminal and is configured to be switched between ON and OFF according to a switch controlling signal provided to the control terminal. The variable resistor is connected to the control terminal and configured to change to a first resistance while the switch device is ON, and to change to a second resistance while the switch device is OFF according to a resistor controlling signal. The first resistance is higher than the second resistance, and the resistor controlling signal is changed corresponding to the switch controlling signal.
    Type: Application
    Filed: September 28, 2015
    Publication date: October 13, 2016
    Inventors: MING-HUI TUNG, AN-MING LEE, LEAF CHEN, CHIEN-WEN CHEN, GUAN-YU CHEN, TSUNG-YEN LIU
  • Publication number: 20160261263
    Abstract: An analog switch circuit is disclosed. The analog switch circuit includes a MOSFET and a control switch. The MOSFET includes a drain electrode, a source electrode, a gate electrode, and a body electrode. A gate bias is applied on the gate electrode to control whether the MOSFET is ON or OFF. The control switch includes a control terminal, a first terminal, a second terminal, and a third terminal. A control bias relating to the gate bias is applied to the control terminal so that the first terminal is connected to the second terminal when the MOSFET is ON, and the first terminal is connected to the third terminal when the MOSFET is OFF. The second terminal is connected to a first voltage source providing a first bias. The third terminal is connected to a second voltage source providing a second bias different from the first bias.
    Type: Application
    Filed: February 19, 2016
    Publication date: September 8, 2016
    Inventors: Guan-Yu CHEN, Leaf CHEN
  • Patent number: 8896362
    Abstract: A control circuit for generating a first control signal and a second control signal includes: an inverter, used for generating an inverted clock according to an input clock; a first delay circuit, used for generating a first delay control signal; a second delay circuit, used for generating a second delay control signal; a first mask circuit, used for generating a first mask signal according to the input clock; a second mask circuit, used for generating a second mask signal according to the inverted input clock; a first logic determining circuit, used for generating the first control signal to the first delay circuit according to the second mask signal and the input clock; and a second logic determining circuit, used for generating the second control signal to the second delay circuit according to the first mask signal and the inverted clock.
    Type: Grant
    Filed: October 3, 2013
    Date of Patent: November 25, 2014
    Assignee: Realtek Semiconductor Corp.
    Inventor: Leaf Chen
  • Publication number: 20140203861
    Abstract: A control circuit for generating a first control signal and a second control signal includes: an inverter, used for generating an inverted clock according to an input clock; a first delay circuit, used for generating a first delay control signal; a second delay circuit, used for generating a second delay control signal; a first mask circuit, used for generating a first mask signal according to the input clock; a second mask circuit, used for generating a second mask signal according to the inverted input clock; a first logic determining circuit, used for generating the first control signal to the first delay circuit according to the second mask signal and the input clock; and a second logic determining circuit, used for generating the second control signal to the second delay circuit according to the first mask signal and the inverted clock.
    Type: Application
    Filed: October 3, 2013
    Publication date: July 24, 2014
    Applicant: Realtek Semiconductor Corp.
    Inventor: Leaf Chen
  • Publication number: 20130229161
    Abstract: A modulating determination apparatus, a modulating determination method, and a power supply circuit thereof are provided. The modulating determination apparatus is electrically connected to an examined circuit and includes a driver circuit and a comparison circuit. The driver circuit provides an impulse signal to a first end of the examined circuit. The comparison circuit is coupled to the first end of the examined circuit to obtain a first detected electric value of the first end. The comparison circuit calculates a difference value between the first detected electric value and a second detected electric value. The comparison circuit produces a comparison result by comparing the difference value with a threshold value. The comparison result indicates whether the examined circuit comprises a passive component, which is used to decide either a first modulating scheme or a second modulating scheme for modulating the power supply circuit to supply an output power.
    Type: Application
    Filed: December 14, 2012
    Publication date: September 5, 2013
    Applicant: REALTEK SEMICONDUCTOR CORPORATION
    Inventor: Leaf CHEN
  • Publication number: 20090190650
    Abstract: A driving signal generation circuit including a transforming circuit and a phase split circuit is disclosed. The transforming circuit is utilized to generate a transformed signal by delaying a rising or falling edge of each pulse of a pulse-width-modulation signal. The phase split circuit generates first and second driving signals by respectively extracting each odd pulse and each even pulse of the transformed signal. Furthermore, disclosed is another driving signal generation circuit including a phase split circuit and a phase shift circuit. The phase split circuit generates first and second push-pull signals by respectively extracting each odd pulse and each even pulse of the pulse-width-modulation signal. The phase shift circuit generates a driving signal by delaying rising and falling edges of each pulse of the first or second push-pull signal.
    Type: Application
    Filed: October 16, 2008
    Publication date: July 30, 2009
    Inventors: Shih-Chung Huang, Leaf Chen
  • Publication number: 20090146718
    Abstract: A delay circuit is disclosed for providing highly stable delay time in digital signal processing. The delay circuit includes a preliminary charging/discharging circuit, a signal processing circuit and an output circuit. The preliminary charging/discharging circuit performs charging and discharging operations based on a logic input signal for generating a voltage signal. The signal processing circuit performs signal processing on the voltage signal for generating a first delay signal and a second delay signal. The output circuit performs logic signal processing on the first and second delay signals for generating a logic output signal lagging behind the logic input signal by a delay time. The delay time is independent of any supply voltage. That is, even though the supply voltage is unstable, the delay circuit is capable of generating a stable logic output signal by performing a signal delay process on a logic input signal regardless of the unstable supply voltage.
    Type: Application
    Filed: September 4, 2008
    Publication date: June 11, 2009
    Inventor: Leaf Chen
  • Publication number: 20090009152
    Abstract: A bias supply, a start-up circuit, and a start-up method for a bias circuit are provided. The bias supply includes the bias circuit, a first switch, a second switch, and a charge storage unit. The first switch is coupled between a first voltage and a node. The first switch determines whether or not to be turned on according to a feedback voltage from the bias circuit. The charge storage unit is coupled between the node and a second voltage. The second switch determines whether or not to output a start-up voltage to the bias circuit according to the voltage of the node. In other words, the present invention utilizes charge/discharge properties of the charge storage unit and the feedback voltage from the bias circuit for controlling whether the second switch outputs a start-up voltage to the bias circuit or not. Therefore, the power consumption of the start-up circuit is decreased.
    Type: Application
    Filed: March 25, 2008
    Publication date: January 8, 2009
    Applicant: BEYOND INNOVATION TECHNOLOGY CO., LTD.
    Inventors: Leaf Chen, Chih-Shun Lee
  • Publication number: 20090002061
    Abstract: A bias supply, a start-up circuit, and a start-up method for a bias circuit are provided. The bias supply includes the bias circuit, an impedance unit, a charge storage unit, and a switch. The impedance unit is coupled between a first voltage and a node. The charge storage unit is coupled between the node and a second voltage. The switch decides whether or not to output a start-up voltage to the bias circuit according to the voltage of the node. In other words, charge/discharge properties of the charge storage unit are utilized for controlling whether the switch outputs a start-up voltage to the bias circuit or not. Therefore, the power consumption of the start-up circuit is decreased.
    Type: Application
    Filed: March 21, 2008
    Publication date: January 1, 2009
    Applicant: BEYOND INNOVATION TECHNOLOGY CO., LTD.
    Inventors: Leaf Chen, Chih-Shun Lee
  • Publication number: 20080315690
    Abstract: An initial circuit is provided. The initial circuit receives a plurality of input signals and controls an initial status of a switching circuit with a plurality of switches. The initial circuit includes a judgment circuit for generating an enable signal according to one of the input signals, and a control circuit for generating a plurality of control signals according to the enable signal and the input signals. The switches are turned off by the control circuit according to the control signals when the switching circuit is in an initial status, and the switches are controlled by the control circuit according to the control signals when the switching circuit is in an operating status.
    Type: Application
    Filed: March 3, 2008
    Publication date: December 25, 2008
    Applicant: BEYOND INNOVATION TECHNOLOGY CO., LTD.
    Inventors: Leaf Chen, Chih-Shun Lee, Chia-Hsin Chen