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).

  • Patent number: 11911359
    Abstract: The present invention provides compositions and methods for stimulating an immune response using cationic lipids alone or in combination with antigens.
    Type: Grant
    Filed: November 3, 2014
    Date of Patent: February 27, 2024
    Assignee: PDS Biotechnology Corporation
    Inventors: Weihsu Chen, Weili Yan, Kenya Johnson, Gregory Conn, Frank Bedu-Addo, Leaf Huang
  • Patent number: 11901804
    Abstract: A power supplying circuit includes a first high-voltage switch, a first low-voltage switch, a second high-voltage switch, a second low-voltage switch, and a controller circuit. The first high-voltage switch receives a first input voltage and generates a first node voltage. The first low-voltage switch is coupled between the first high-voltage switch and an output terminal. The second high-voltage switch receives a second input voltage and generates a second node voltage. The second low-voltage switch is coupled between the second high-voltage switch and the output terminal. The controller circuit controls the first high-voltage switch, the first low-voltage switch, the second high-voltage switch, and the second low-voltage switch according to the first node voltage and the second node voltage such that an output voltage is outputted to the output terminal.
    Type: Grant
    Filed: June 23, 2022
    Date of Patent: February 13, 2024
    Assignee: Realtek Semiconductor Corporation
    Inventors: Jiun Hung Pan, Leaf Chen
  • Patent number: 11750000
    Abstract: An electronic device having a universal serial bus (USB) power delivery function includes a connector, an electrostatic discharge (ESD) protection circuit, a power reception notification circuit, and a control circuit. The connector is coupled to a USB host. The connector includes a configuration channel (CC) pin. The power reception notification circuit is configured to turn on, in response to an enable signal, a pull-down path of a pull-down circuit of the ESD protection circuit. The configuration channel pin generates a pull-down voltage through the pull-down path of the pull-down circuit when the pull-down path is turned on. The control circuit is configured to send the enable signal to the power reception notification circuit when a trigger signal that meets a power reception condition is detected. The control circuit controls the connector to draw power from the USB host when the pull-down voltage of the connector is greater than a pull-down threshold.
    Type: Grant
    Filed: November 15, 2021
    Date of Patent: September 5, 2023
    Assignee: REALTEK SEMICONDUCTOR CORP.
    Inventors: Ya-Hsuan Sung, Leaf Chen, Li-Cheng Chu
  • Publication number: 20230268913
    Abstract: A bidirectional signal conversion circuit is configured to perform a signal conversion between a first port and a second port, and includes a switch, a first pull-up resistor, a second pull-up resistor, a first output-response enhancement circuit, and a second output-response enhancement circuit. The switch is coupled between the first port and the second port, and operates according to a bias. The first (second) pull-up resistor is coupled between the first (second) port and a high (low) voltage terminal having a high (low) voltage. The first (second) output-response enhancement circuit includes a first (second) alternative-current (AC) coupling circuit and a first (second) output-stage circuit. When the first (second) port and the second (first) port functions as an input port and an output port respectively, the first (second) output-response enhancement circuit is operable to accelerate the transient response of the output port.
    Type: Application
    Filed: February 14, 2023
    Publication date: August 24, 2023
    Inventors: LEAF CHEN, JIUN-HUNG PAN
  • Publication number: 20230155480
    Abstract: A power supplying circuit includes a first high-voltage switch, a first low-voltage switch, a second high-voltage switch, a second low-voltage switch, and a controller circuit. The first high-voltage switch receives a first input voltage and generates a first node voltage. The first low-voltage switch is coupled between the first high-voltage switch and an output terminal. The second high-voltage switch receives a second input voltage and generates a second node voltage. The second low-voltage switch is coupled between the second high-voltage switch and the output terminal. The controller circuit controls the first high-voltage switch, the first low-voltage switch, the second high-voltage switch, and the second low-voltage switch according to the first node voltage and the second node voltage such that an output voltage is outputted to the output terminal.
    Type: Application
    Filed: June 23, 2022
    Publication date: May 18, 2023
    Inventors: Jiun Hung PAN, Leaf CHEN
  • Patent number: 11569813
    Abstract: The present invention discloses a USB signal output circuit having reverse current prevention mechanism. A switch circuit turns on when a switch control terminal receives a first high level voltage to output a signal from a signal input terminal to a signal output terminal. A first voltage pull-low circuit includes a passive-component high-pass filter circuit and a discharging circuit. The passive-component high-pass filter circuit couples an output terminal voltage of the signal output terminal to a pull-low control terminal. The discharging circuit turns on when a voltage of the pull-low control terminal is larger than a predetermined voltage level to discharge the switch control terminal to pull the switch control terminal to a second high level voltage. A second voltage pull-low circuit pulls the switch control terminal to a low level voltage when the output terminal voltage is larger than a reference voltage and does not have a glitch.
    Type: Grant
    Filed: March 19, 2021
    Date of Patent: January 31, 2023
    Assignee: REALTEK SEMICONDUCTOR CORPORATION
    Inventors: Li-Cheng Chu, Leaf Chen
  • Patent number: 11418052
    Abstract: The present disclosure relates to a power circuit including a power supply circuit and a first control circuit. The power supply circuit is electrically connected to a power supply source and a power terminal for selectively providing power to the power terminal. The first control circuit is electrically connected to the power supply circuit and configured to receive a detection signal to enable or disable the power supply circuit. When the detection signal is enabled, the first control circuit provides a first enable signal to the power supply circuit, so that the power supply circuit provides power to the power terminal. When the detection signal is at the disable level, the first control circuit is configured to provide the first disable signal to the power supply circuit, so that the power supply circuit stops providing power from the power supply source to the power terminal.
    Type: Grant
    Filed: February 21, 2020
    Date of Patent: August 16, 2022
    Assignee: REALTEK SEMICONDUCTOR CORPORATION
    Inventors: Ya-Hsuan Sung, Leaf Chen
  • Publication number: 20220166241
    Abstract: An electronic device having a universal serial bus (USB) power delivery function includes a connector, an electrostatic discharge (ESD) protection circuit, a power reception notification circuit, and a control circuit. The connector is coupled to a USB host. The connector includes a configuration channel (CC) pin. The power reception notification circuit is configured to turn on, in response to an enable signal, a pull-down path of a pull-down circuit of the ESD protection circuit. The configuration channel pin generates a pull-down voltage through the pull-down path of the pull-down circuit when the pull-down path is turned on. The control circuit is configured to send the enable signal to the power reception notification circuit when a trigger signal that meets a power reception condition is detected. The control circuit controls the connector to draw power from the USB host when the pull-down voltage of the connector is greater than a pull-down threshold.
    Type: Application
    Filed: November 15, 2021
    Publication date: May 26, 2022
    Applicant: REALTEK SEMICONDUCTOR CORP.
    Inventors: Ya-Hsuan Sung, Leaf Chen, Li-Cheng Chu
  • Patent number: 11342840
    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: Grant
    Filed: October 24, 2019
    Date of Patent: May 24, 2022
    Assignee: REALTEK SEMICONDUCTOR CORPORATION
    Inventors: Leaf Chen, Ya-Hsuan Sung, Li-Chen Liu
  • Patent number: 11288219
    Abstract: A USB switching circuit includes a first multiplexer, a second multiplexer coupled with the first multiplexer through transmission paths, and a voltage regulation circuit coupled with the first and second multiplexers. The first multiplexer distributes first data signals to the transmission paths according to first control signals. The second multiplexer distributes a second data signal to the transmission paths according to second control signals. The voltage regulation circuit sets a maximum voltage and a minimum voltage of the first data signals to corresponding to a common voltage. The maximum voltage of the first data signals is not higher than a maximum voltage of the second control signals, or the minimum voltage of the first data signals is not lower than a minimum voltage of the second control signals. The first data signals and the second data signal are generated according to different communication protocols.
    Type: Grant
    Filed: October 27, 2020
    Date of Patent: March 29, 2022
    Assignee: REALTEK SEMICONDUCTOR CORPORATION
    Inventors: Kai-Yuan Yin, Wen-Bin Wu, Leaf Chen, Bo-Yu Chen
  • Patent number: 11237586
    Abstract: Disclosed is a reference voltage generating circuit including a bandgap reference voltage generating circuit, a voltage controlled current source circuit, a current mirror circuit, an input voltage generating circuit, and a voltage controlled voltage source circuit. The bandgap reference voltage generating circuit generates a bandgap reference voltage. The voltage controlled current source circuit generates a reference current according to the bandgap reference voltage. The current mirror circuit generates a mirrored current according to the reference current. The input voltage generating circuit determines an input voltage according to the mirrored current. The voltage controlled voltage source circuit generates a reference voltage according to the input voltage.
    Type: Grant
    Filed: June 2, 2020
    Date of Patent: February 1, 2022
    Assignee: REALTEK SEMICONDUCTOR CORPORATION
    Inventor: Leaf Chen
  • Publication number: 20210297076
    Abstract: The present invention discloses a USB signal output circuit having reverse current prevention mechanism. A switch circuit turns on when a switch control terminal receives a first high level voltage to output a signal from a signal input terminal to a signal output terminal. A first voltage pull-low circuit includes a passive-component high-pass filter circuit and a discharging circuit. The passive-component high-pass filter circuit couples an output terminal voltage of the signal output terminal to a pull-low control terminal. The discharging circuit turns on when a voltage of the pull-low control terminal is larger than a predetermined voltage level to discharge the switch control terminal to pull the switch control terminal to a second high level voltage. A second voltage pull-low circuit pulls the switch control terminal to a low level voltage when the output terminal voltage is larger than a reference voltage and does not have a glitch.
    Type: Application
    Filed: March 19, 2021
    Publication date: September 23, 2021
    Inventors: LI-CHENG CHU, LEAF CHEN
  • Patent number: 11038505
    Abstract: Disclosed is a switch control circuit coupled between a switch control node and a voltage terminal. The switch control node is between an input circuit and a switch. The switch control circuit includes: an electronic component being turned on or off according to voltages of the switch control node and a control voltage node in a power-on state and preventing the voltage of the switch control node from being higher than a predetermined voltage in a power-off state; a control circuit outputting a control signal to the control voltage node in the power-on state and having no effective control over the voltage of the control voltage node in the power-off state; and a resistive component coupled between the control voltage node and voltage terminal. The electronic and resistive components function as at least a part of a leakage path to assist in turning off the switch in the power-off state.
    Type: Grant
    Filed: June 12, 2020
    Date of Patent: June 15, 2021
    Assignee: REALTEK SEMICONDUCTOR CORPORATION
    Inventor: Leaf Chen
  • Publication number: 20210141753
    Abstract: A USB switching circuit includes a first multiplexer, a second multiplexer coupled with the first multiplexer through transmission paths, and a voltage regulation circuit coupled with the first and second multiplexers. The first multiplexer distributes first data signals to the transmission paths according to first control signals. The second multiplexer distributes a second data signal to the transmission paths according to second control signals. The voltage regulation circuit sets a maximum voltage and a minimum voltage of the first data signals to corresponding to a common voltage. The maximum voltage of the first data signals is not higher than a maximum voltage of the second control signals, or the minimum voltage of the first data signals is not lower than a minimum voltage of the second control signals. The first data signals and the second data signal are generated according to different communication protocols.
    Type: Application
    Filed: October 27, 2020
    Publication date: May 13, 2021
    Inventors: Kai-Yuan YIN, Wen-Bin WU, Leaf CHEN, Bo-Yu CHEN
  • Patent number: 11003617
    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: Grant
    Filed: November 14, 2019
    Date of Patent: May 11, 2021
    Assignee: REALTEK SEMICONDUCTOR CORPORATION
    Inventor: Leaf Chen
  • Publication number: 20200395934
    Abstract: Disclosed is a switch control circuit coupled between a switch control node and a voltage terminal. The switch control node is between an input circuit and a switch. The switch control circuit includes: an electronic component being turned on or off according to voltages of the switch control node and a control voltage node in a power-on state and preventing the voltage of the switch control node from being higher than a predetermined voltage in a power-off state; a control circuit outputting a control signal to the control voltage node in the power-on state and having no effective control over the voltage of the control voltage node in the power-off state; and a resistive component coupled between the control voltage node and voltage terminal. The electronic and resistive components function as at least a part of a leakage path to assist in turning off the switch in the power-off state.
    Type: Application
    Filed: June 12, 2020
    Publication date: December 17, 2020
    Inventor: LEAF CHEN
  • Publication number: 20200387186
    Abstract: Disclosed is a reference voltage generating circuit including a bandgap reference voltage generating circuit, a voltage controlled current source circuit, a current mirror circuit, an input voltage generating circuit, and a voltage controlled voltage source circuit. The bandgap reference voltage generating circuit generates a bandgap reference voltage. The voltage controlled current source circuit generates a reference current according to the bandgap reference voltage. The current mirror circuit generates a mirrored current according to the reference current. The input voltage generating circuit determines an input voltage according to the mirrored current. The voltage controlled voltage source circuit generates a reference voltage according to the input voltage.
    Type: Application
    Filed: June 2, 2020
    Publication date: December 10, 2020
    Inventor: LEAF CHEN
  • Patent number: 10853295
    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: Grant
    Filed: September 19, 2019
    Date of Patent: December 1, 2020
    Assignee: Realtek Semiconductor Corp.
    Inventors: Jiun-Hung Pan, Leaf Chen
  • Publication number: 20200303946
    Abstract: The present disclosure relates to a power circuit including a power supply circuit and a first control circuit. The power supply circuit is electrically connected to a power supply source and a power terminal for selectively providing power to the power terminal. The first control circuit is electrically connected to the power supply circuit and configured to receive a detection signal to enable or disable the power supply circuit. When the detection signal is enabled, the first control circuit provides a first enable signal to the power supply circuit, so that the power supply circuit provides power to the power terminal. When the detection signal is at the disable level, the first control circuit is configured to provide the first disable signal to the power supply circuit, so that the power supply circuit stops providing power from the power supply source to the power terminal.
    Type: Application
    Filed: February 21, 2020
    Publication date: September 24, 2020
    Inventors: Ya-Hsuan SUNG, Leaf CHEN
  • Patent number: 10749523
    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: Grant
    Filed: May 8, 2019
    Date of Patent: August 18, 2020
    Assignee: Realtek Semiconductor Corp.
    Inventors: Ya-Hsuan Sung, Leaf Chen