Patents by Inventor Nien-Hui Kung

Nien-Hui Kung 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: 8378640
    Abstract: A charging circuit with an application system thereof provides an error amplifier to control a transistor switch for controlling the charging power source to charges the battery. When the voltage difference between the power source and load terminals of the transistor switch drops along with the transistor switch being turned on, the output voltage of the error amplifier changes as well to increase the turning-on resistance of the transistor switch such that the voltage difference between the power source and load terminals is capable of maintaining at a value above a certain reference level for avoiding the unstable state resulting from the charging circuit being turned on and off frequently.
    Type: Grant
    Filed: December 7, 2009
    Date of Patent: February 19, 2013
    Assignee: Richtek Technology Corp.
    Inventors: Li-Wei Lee, Nien-Hui Kung, Kwan-Jen Chu, Hsuan-Kai Wang
  • Publication number: 20130015822
    Abstract: The present invention discloses a multi-purpose power management apparatus, a power path control circuit, and a control method therefor. The multi-purpose power management apparatus controls power conversion between an input power and an output power and charging operation from the output power to a battery. The multi-purpose power management apparatus includes: a switch circuit including at least one power transistor; a switch control circuit generating a PWM signal to control the power transistor, for controlling the power conversion between the input power and the output power; a charging management circuit for controlling the charging operation from the output power to the battery; and a path selection circuit for determining whether the charging operation is controlled by the charging management circuit.
    Type: Application
    Filed: July 12, 2011
    Publication date: January 17, 2013
    Inventor: Nien-Hui Kung
  • Publication number: 20130002196
    Abstract: A charger for a portable device includes a USB detector connected to a data pin to detect the effective resistance on the data pin before a USB transceiver is enabled, to identify USB or adapter plug in and control a charging current for a battery accordingly.
    Type: Application
    Filed: September 11, 2012
    Publication date: January 3, 2013
    Applicant: RICHTEK TECHNOLOGY CORP.
    Inventors: LI-WEI LEE, NIEN-HUI KUNG, KWAN-JEN CHU, YING-HSIN HSING
  • Publication number: 20130002195
    Abstract: A charger for a portable device includes a USB detector connected to a data pin to detect the effective resistance on the data pin before a USB transceiver is enabled, to identify USB or adapter plug in and control a charging current for a battery accordingly.
    Type: Application
    Filed: September 11, 2012
    Publication date: January 3, 2013
    Applicant: RICHTEK TECHNOLOGY CORP.
    Inventors: Li-Wei LEE, Nien-Hui KUNG, Kwan-Jen CHU, Ying-Hsin HSING
  • Publication number: 20120319662
    Abstract: The present invention discloses a switching regulator, a control circuit and a control method therefor. The switching regulator comprises an upper gate switch, a lower gate switch, and an inductor connected to a switching node. When a current passing through the upper gate switch or the inductor is lower than a threshold, the lower gate switch is kept OFF until a next cycle, and during the cycle wherein the lower gate switch is OFF, the upper gate switch is turned ON for a period of time.
    Type: Application
    Filed: June 16, 2011
    Publication date: December 20, 2012
    Inventor: Nien-Hui Kung
  • Patent number: 8283974
    Abstract: A fast start-up low-voltage bandgap reference voltage generator uses two current generators to provide a first current having a positive temperature coefficient and a second current having a negative temperature coefficient, respectively, and a resistor to generate a temperature independent output voltage according to the sum of the first and second currents. The current generator for providing the first current has a self-bias circuit which uses a single MOSFET to establish the first current, and thereby avoids error caused by mismatched MOSFETs.
    Type: Grant
    Filed: January 4, 2011
    Date of Patent: October 9, 2012
    Assignee: Richtek Technology Corp.
    Inventors: Kwan-Jen Chu, Nien-Hui Kung, Hsuan-Kai Wang
  • Patent number: 8269461
    Abstract: A hybrid battery charger includes a control circuit and a power stage. The control circuit includes an error amplifier to generate a first error signal and a second error signal according to an output voltage and an output current of the hybrid battery charger, a linear controller to generate a first control signal according to the first error signal, a PWM controller to generate a second control signal and a third control signal according to the second error signal, and according to a mode signal, a multiplexer to select the first control signal for the power stage to operate the hybrid battery charger in a linear mode, or the second and third control signals for the power stage to operate the hybrid battery charger in a switching mode.
    Type: Grant
    Filed: July 7, 2010
    Date of Patent: September 18, 2012
    Assignee: Richtek Technology Corp.
    Inventors: Nien-Hui Kung, Kwan-Jen Chu
  • Publication number: 20120217936
    Abstract: The present invention discloses a power management circuit, including: a first voltage regulator, which converts an input voltage to an output voltage; a second voltage regulator coupled between the output voltage and a battery; and a voltage difference control circuit, which receives the output voltage and a voltage of the battery, and outputs a voltage difference control signal to control the first voltage regulator. The voltage difference control circuit includes: a battery reference voltage determination circuit, which generates a battery reference voltage related to the battery voltage, and an error amplifier, which receives the output voltage and the battery reference voltage and generates the voltage difference control signal.
    Type: Application
    Filed: February 24, 2011
    Publication date: August 30, 2012
    Inventor: NIEN-HUI KUNG
  • Patent number: 8248049
    Abstract: In an NMOSFET-base linear charger, a pair of common gate charging NMOSFET and sensing NMOSFET have their sources coupled together or virtually shorted to each other, so that these two NMOSFETs have a same gate-source voltage and thereby the sensing NMOSFET reflects the drain-source current of the charging NMOSFET on its drain-source current. From the drain-source current of the sensing NMOSFET, a current sensing signal is generated to control the gate voltage of the charging NMOSFET. By implementing the current source with NMOSFETs, the linear charger has smaller die area and less power loss.
    Type: Grant
    Filed: September 30, 2008
    Date of Patent: August 21, 2012
    Assignee: Richtek Technology Corp.
    Inventors: Nien-Hui Kung, Kwan-Jen Chu
  • Publication number: 20120169294
    Abstract: A circuit and method for power path management track the input voltage at a power input terminal to generate a reference voltage, and generate a control signal for controlling a charger control circuit coupled between a power output terminal and a charger output terminal according to the difference between the voltage at the power output terminal and the reference voltage.
    Type: Application
    Filed: December 30, 2011
    Publication date: July 5, 2012
    Applicant: Richtek Technology Corp.
    Inventors: Hsuan-Kai WANG, Nien-Hui KUNG, Chia-Hsiang LIN
  • Patent number: 8203234
    Abstract: A power safety system includes a first MOS, a second MOS, a switch and a body controller. The first MOS is connected between a power input and a power output. The second MOSFET is connected between the power output and a charging output. The switch has an end connected to the body of the first MOS, and the opposite end switched between the source and the drain of the first MOS. A body controller controls the switch according to the voltage at the power input and the voltage at the power output, to connect the body of the first MOS to the source or the drain of the first MOS. By switching the switch, the first MOS will have a parasitic diode effective to prevent a reverse current from the power output to the power input.
    Type: Grant
    Filed: March 9, 2010
    Date of Patent: June 19, 2012
    Assignee: Richtek Technology Corp.
    Inventors: Li-Wei Lee, Nien-Hui Kung, Kwan-Jen Chu, Chun-Tsung Chen
  • Publication number: 20120112705
    Abstract: The present invention discloses a charger circuit. The charger circuit comprises a control circuit and at least two charging paths. The control circuit determines to activate or inactivate each charging path according to a battery feedback signal representing the charging status. Accordingly, the battery is charged by input power in an optimal way so that the charging efficiency is improved and the overheating problem is solved.
    Type: Application
    Filed: May 26, 2011
    Publication date: May 10, 2012
    Inventors: Hsuan-Kai Wang, Nien-Hui Kung, Wei-I Li
  • Patent number: 8169208
    Abstract: For output current detection of a voltage regulator, the currents in a high-side transistor and a low-side transistor of the voltage regulator are sensed and summarized to a summed current to flow through a setting resistor. The voltage variation on the setting resistor is monitored to provide a feedback signal for feedback control in the voltage regulator. This detection scheme removes the current sensing resistor from the charging current path of the voltage regulator to prevent efficiency loss on it, and is much less sensitive to noise interference because greater voltage variation is available by using a greater setting resistor.
    Type: Grant
    Filed: June 18, 2009
    Date of Patent: May 1, 2012
    Assignee: Richtek Technology Corp.
    Inventors: Nien-Hui Kung, Kwan-Jen Chu
  • Patent number: 8159195
    Abstract: The present invention discloses an overvoltage protection (OVP) circuit for use in a charger circuit system, comprising: a power transistor electrically connected between a voltage supply and a battery; an OVP circuit which turns off the transistor when a voltage supply exceeds a threshold value; and a multiplexing circuit electrically connected between an output of the OVP circuit and the gate of the transistor. The present invention also discloses a charger circuit with an OVP function, comprising: a single power transistor electrically connected between a voltage supply and a battery; an OVP control circuit which turns off the power transistor when a voltage supply exceeds a threshold value; and a charger control circuit which controls the gate of the power transistor to determine a charge current to the battery when the voltage supply does not reach the threshold value.
    Type: Grant
    Filed: March 10, 2009
    Date of Patent: April 17, 2012
    Assignee: Richtek Technology Corporation
    Inventors: Chien-Ping Lu, Nien-Hui Kung, Li-Wei Lee, Kwan-Jen Chu, Ying-Hsin Hsing, Chun-Tsung Chen
  • Patent number: 8140726
    Abstract: The present invention discloses a single wire transmission interface comprising: a signal detection circuit detecting level switchings of a transmission signal from a single wire, and generating an enable signal and a decoded signal corresponding to the transmission signal, the level switchings including first switchings from a first level to a second level and second switchings from the second level to the first level, wherein the enable signal starts according to one first switching of the transmission signal, and stops when no first switching occur in a predetermined period after one second switching of the transmission signal, and wherein rising edges (or falling edges) of the decoded signal correspond to the first switchings of the transmission signal; a counter, under enablement by the enable signal, counting a number of the rising edges (or the rising edges) of the decoded signal or the first switchings of the transmission signal, and generating a count; a single short pulse generator generating a shor
    Type: Grant
    Filed: October 23, 2009
    Date of Patent: March 20, 2012
    Assignee: Richtek Technology Corporation, R.O.C.
    Inventors: Nien-Hui Kung, Kwan-Jen Chu
  • Publication number: 20120038338
    Abstract: For output current detection of a voltage regulator, the currents in a high-side transistor and a low-side transistor of the voltage regulator are sensed and summarized to a summed current to flow through a setting resistor. The voltage variation on the setting resistor is monitored to provide a feedback signal for feedback control in the voltage regulator. This detection scheme removes the current sensing resistor from the charging current path of the voltage regulator to prevent efficiency loss on it, and is much less sensitive to noise interference because greater voltage variation is available by using a greater setting resistor.
    Type: Application
    Filed: October 24, 2011
    Publication date: February 16, 2012
    Applicant: RICHTEK TECHNOLOGY CORP.
    Inventors: NIEN-HUI KUNG, KWAN-JEN CHU
  • Patent number: 8085014
    Abstract: The present invention discloses a dual power switch and a voltage regulator using the dual power switch. The dual power switch comprises a PMOS power switch and an NMOS power switch connected in parallel and operating according to corresponding predetermined conditions, respectively.
    Type: Grant
    Filed: February 17, 2009
    Date of Patent: December 27, 2011
    Assignee: Richtek Technology Corporation
    Inventors: Nien-Hui Kung, Kwan-Jen Chu, Chun-Tsung Chen, Tzu-Huan Chiu
  • Patent number: 8049462
    Abstract: The present invention discloses a universal serial bus (USB) charging circuit, comprising: a charging path for charging a battery from a USB host; a charging switch located on the charging path; a current sensing circuit for sensing current information on the charging path; a maximum available current detection circuit for detecting the maximum available current from the USB host; and a loop controller circuit for controlling the charging switch so that the charging current on the charging path is substantially equal to the maximum available current detected by the maximum available current detection circuit, wherein the maximum available current detection circuit detects the maximum available current during circuit initialization and stores it.
    Type: Grant
    Filed: September 18, 2008
    Date of Patent: November 1, 2011
    Assignee: Richtek Technology Corporation, R.O.C.
    Inventors: Nien-Hui Kung, Kwan-Jen Chu, Jing-Meng Liu
  • Patent number: 7994728
    Abstract: The present invention discloses a boost driver circuit which converts an input voltage to an output voltage and supplies it to a load, the boost driver circuit comprising: a power transistor electrically connected with a node between the input voltage and the output voltage; a pulse width modulation driver circuit for controlling the operation of the power transistor; an output node electrically connected with the output voltage; a feedback node electrically connected with the load; a low voltage transistor electrically connected with the feedback node; and a clamp and fast discharge circuit electrically connected with the feedback node for discharging the feedback node when the voltage at the feedback node is higher than a predetermined voltage.
    Type: Grant
    Filed: April 1, 2009
    Date of Patent: August 9, 2011
    Assignee: Richtek Technology Corporation
    Inventors: Kwan-Jen Chu, Nien-Hui Kung, Tzu-Huan Chiu, Chien-Ping Lu
  • Publication number: 20110169561
    Abstract: A fast start-up low-voltage bandgap reference voltage generator uses two current generators to provide a first current having a positive temperature coefficient and a second current having a negative temperature coefficient, respectively, and a resistor to generate a temperature independent output voltage according to the sum of the first and second currents. The current generator for providing the first current has a self-bias circuit which uses a single MOSFET to establish the first current, and thereby avoids error caused by mismatched MOSFETs.
    Type: Application
    Filed: January 4, 2011
    Publication date: July 14, 2011
    Applicant: RICHTEK TECHNOLOGY CORP.
    Inventors: KWAN-JEN CHU, NIEN-HUI KUNG, HSUAN-KAI WANG