Patents by Inventor Li-Wen Fang

Li-Wen Fang 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: 12027966
    Abstract: A control circuit for controlling a stackable multiphase power converter includes: a synchronization terminal; a synchronization signal connected to the synchronization terminals of a plurality of the control circuits in parallel, wherein the synchronization signal includes a plurality of pulses to be successively counted as a count number; and a reset signal, configured to reset and initiate the count number; wherein the control circuit further comprises a phase-sequence number, wherein the control circuit enables a corresponding power stage circuit to generate a phase of the output power when the count number reaches the phase-sequence number.
    Type: Grant
    Filed: August 21, 2022
    Date of Patent: July 2, 2024
    Assignee: RICHTEK TECHNOLOGY CORPORATION
    Inventors: Ta-Yung Yang, Wei-Chuan Wu, Chih-Hao Yang, Ping-Ching Huang, Li-Wen Fang
  • Patent number: 11929681
    Abstract: A scalable multi-phase switching converter includes: converter modules, each including: a loop control unit, which generates a basic trigger pulse according to a feedback signal in master operation mode; and a switching control unit, which determines an operation mode and a corresponding phase serial order according to a setting signal received by a setting pin in a setting mode, and generates a multi-phase trigger pulse signal at a trigger pin according to the basic trigger pulse in master operation mode. The switching control unit receives the multi-phase trigger pulse signal at the trigger pin in slave operation mode. The switching control unit generates an ON-trigger pulse according to the multi-phase trigger pulse signal and the corresponding phase serial order. An ON-period determination unit generates a conduction control pulse according to the ON-trigger pulse to control a corresponding inductor. The trigger pins of the converter modules are coupled to each other.
    Type: Grant
    Filed: February 11, 2022
    Date of Patent: March 12, 2024
    Assignee: RICHTEK TECHNOLOGY CORPORATION
    Inventors: Chih-Wen Hsiao, Ping-Ching Huang, Li-Wen Fang
  • Publication number: 20230238875
    Abstract: A control circuit for controlling a stackable multiphase power converter includes: a synchronization terminal; a synchronization signal connected to the synchronization terminals of a plurality of the control circuits in parallel, wherein the synchronization signal includes a plurality of pulses to be successively counted as a count number; and a reset signal, configured to reset and initiate the count number; wherein the control circuit further comprises a phase-sequence number, wherein the control circuit enables a corresponding power stage circuit to generate a phase of the output power when the count number reaches the phase-sequence number.
    Type: Application
    Filed: August 21, 2022
    Publication date: July 27, 2023
    Inventors: Ta-Yung Yang, Wei-Chuan Wu, Chih-Hao Yang, Ping-Ching Huang, Li-Wen Fang
  • Publication number: 20220271668
    Abstract: A scalable multi-phase switching converter includes: converter modules, each including: a loop control unit, which generates a basic trigger pulse according to a feedback signal in master operation mode; and a switching control unit, which determines an operation mode and a corresponding phase serial order according to a setting signal received by a setting pin in a setting mode, and generates a multi-phase trigger pulse signal at a trigger pin according to the basic trigger pulse in master operation mode. The switching control unit receives the multi-phase trigger pulse signal at the trigger pin in slave operation mode. The switching control unit generates an ON-trigger pulse according to the multi-phase trigger pulse signal and the corresponding phase serial order. An ON-period determination unit generates a conduction control pulse according to the ON-trigger pulse to control a corresponding inductor. The trigger pins of the converter modules are coupled to each other.
    Type: Application
    Filed: February 11, 2022
    Publication date: August 25, 2022
    Inventors: Chih-Wen Hsiao, Ping-Ching Huang, Li-Wen Fang
  • Patent number: 9356518
    Abstract: An over-voltage protection circuit is applied to a switching voltage converting circuit. The switching voltage converting circuit manipulates an upper bridge power switch in the circuit, so as to convert an input voltage into an output voltage by an inductor. A channel of the upper bridge power switch and the inductor are coupled to a phase end. The over-voltage protection circuit includes: a comparator, coupled to the switching voltage converting circuit, wherein when a voltage of the phase end is higher than a voltage limiting threshold, an output end of the comparator outputs a first voltage level; and a pulse width detection unit, coupled to the output end of the comparator, wherein when the output end of the comparator remains the first voltage level for a time period longer than a protection period, the pulse width detection unit outputs an over-voltage protection activation signal.
    Type: Grant
    Filed: October 30, 2014
    Date of Patent: May 31, 2016
    Assignee: RICHTEK TECHNOLOGY CORP
    Inventors: An-Tung Chen, Li-Wen Fang, Chih-Hao Yang
  • Patent number: 9276473
    Abstract: A voltage converting controller is applied to a switching voltage converting circuit, in which the voltage converting controller periodically operates a high-side power switch and a low-side power switch in the switching voltage converting circuit with a high-side control signal and a low-side control signal, respectively, so as to convert an input voltage into an output voltage via an inductor. Defining an ideal duty cycle as the rating value of the output voltage divided by the value of the input voltage, when the ideal duty cycle is less than one threshold duty cycle, then the period of the high-side control signal is a constant; and when the ideal duty cycle is greater than the threshold duty cycle, the period of the high-side control signal and the period of the ideal duty cycle are positively correlated.
    Type: Grant
    Filed: January 7, 2015
    Date of Patent: March 1, 2016
    Assignee: RICHTEK TECHNOLOGY CORP
    Inventors: An-Tung Chen, Li-Wen Fang, Chih-Hao Yang, Yu-Chiao Hsieh
  • Publication number: 20160043627
    Abstract: An over-voltage protection circuit is applied to a switching voltage converting circuit. The switching voltage converting circuit manipulates an upper bridge power switch in the circuit, so as to convert an input voltage into an output voltage by an inductor. A channel of the upper bridge power switch and the inductor are coupled to a phase end. The over-voltage protection circuit includes: a comparator, coupled to the switching voltage converting circuit, wherein when a voltage of the phase end is higher than a voltage limiting threshold, an output end of the comparator outputs a first voltage level; and a pulse width detection unit, coupled to the output end of the comparator, wherein when the output end of the comparator remains the first voltage level for a time period longer than a protection period, the pulse width detection unit outputs an over-voltage protection activation signal.
    Type: Application
    Filed: October 30, 2014
    Publication date: February 11, 2016
    Inventors: An-Tung Chen, Li-Wen Fang, Chih-Hao Yang
  • Patent number: 9088204
    Abstract: A control circuit of a switching regulator includes a control pin for coupling with an external resistor; a resistor detecting circuit for detecting a resistance of the external resistor; a current generating module for generating a corresponding control current according to a detection result of the resistor detecting circuit; an oscillating circuit for generating a clock signal; and a mode-switching circuit. When the mode-switching circuit configures the oscillating circuit to operate in a resistor-controlled mode, the oscillating circuit generates the clock signal according to the control current so that the clock signal has a frequency corresponding to the resistance of the external resistor. When the mode-switching circuit configures the oscillating circuit to operate in a signal-controlled mode, the oscillating circuit generates the clock signal according to an external synchronous signal coupled with the control pin so that the clock signal is synchronized with the external synchronous signal.
    Type: Grant
    Filed: June 7, 2013
    Date of Patent: July 21, 2015
    Assignee: Richtek Technology Corporation
    Inventors: Li-Wen Fang, Ping-Ching Huang, Cheng-Kuang Lin, An-Tung Chen
  • Patent number: 8878304
    Abstract: The present invention discloses a fuse circuit for final test trimming of an integrated circuit (IC) chip. The fuse circuit includes at least one electrical fuse, at least one control switch corresponding to the electrical fuse, and a resistant device. The electrical fuse is connected with the control switch in series between a predetermined pin and a grounding pin. The control switch receives a control signal to determine whether a predetermined current flows through the corresponding electrical fuse and breaks the electrical fuse. The resistant device is coupled between a bulk terminal and a source terminal to increase a resistance of a parasitic channel, such that an electrostatic discharge (ESD) protection is enhanced, and errors of final test trimming of an IC chip are avoided.
    Type: Grant
    Filed: January 25, 2012
    Date of Patent: November 4, 2014
    Assignee: Richtek Technology Corporation, R.O.C.
    Inventors: Li-Wen Fang, Chih-Hao Yang, An-Tung Chen
  • Patent number: 8669747
    Abstract: The present invention discloses a constant on-time switching regulator, a control method therefor, and an on-time calculation circuit for calculating an on-time period of a constant on-time switching regulator. The on-time calculation circuit calculates on-time according to practical conditions. It includes: a driver gate receiving a gate signal of a power switch in a switching regulator, the driver gate operating between high and low levels of a first reference voltage and ground; a low pass filter receiving an output from the driver gate and generating a second reference voltage, a ratio between the second reference voltage and the first reference voltage being substantially the same as a duty ratio of the gate signal; and an on-time generator comparing the second reference voltage with a ramp signal to determine an on-time of the power switch.
    Type: Grant
    Filed: July 20, 2011
    Date of Patent: March 11, 2014
    Assignee: Ricktek Technology Corporation, R.O.C.
    Inventors: Li-Wen Fang, Ting-Jung Tai, Chih-Hao Yang
  • Publication number: 20130342183
    Abstract: A control circuit of a switching regulator includes a control pin for coupling with an external resistor; a resistor detecting circuit for detecting a resistance of the external resistor; a current generating module for generating a corresponding control current according to a detection result of the resistor detecting circuit; an oscillating circuit for generating a clock signal; and a mode-switching circuit. When the mode-switching circuit configures the oscillating circuit to operate in a resistor-controlled mode, the oscillating circuit generates the clock signal according to the control current so that the clock signal has a frequency corresponding to the resistance of the external resistor. When the mode-switching circuit configures the oscillating circuit to operate in a signal-controlled mode, the oscillating circuit generates the clock signal according to an external synchronous signal coupled with the control pin so that the clock signal is synchronized with the external synchronous signal.
    Type: Application
    Filed: June 7, 2013
    Publication date: December 26, 2013
    Inventors: Li-Wen FANG, Ping-Ching HUANG, Cheng-Kuang LIN, An-Tung CHEN
  • Patent number: 8531166
    Abstract: The present invention discloses a constant on-time switching regulator, a control method therefor, and an on-time calculation circuit for calculating an on-time period of a constant on-time switching regulator. The on-time calculation circuit calculates on-time according to practical conditions. It includes: a driver gate receiving a gate signal of a power switch in a switching regulator, the driver gate operating between high and low levels of a first reference voltage and ground; a low pass filter receiving an output from the driver gate and generating a second reference voltage, a ratio between the second reference voltage and the first reference voltage being substantially the same as a duty ratio of the gate signal; and an on-time generator comparing the second reference voltage with a ramp signal to determine an on-time of the power switch.
    Type: Grant
    Filed: April 19, 2011
    Date of Patent: September 10, 2013
    Assignee: Richtek Technology Corporation, R.O.C.
    Inventors: Li-Wen Fang, Ting-Jung Tai, Chih-Hao Yang
  • Publication number: 20130113049
    Abstract: The present invention discloses a fuse circuit for final test trimming of an integrated circuit (IC) chip. The fuse circuit includes at least one electrical fuse, at least one control switch corresponding to the electrical fuse, and a resistant device. The electrical fuse is connected with the control switch in series between a predetermined pin and a grounding pin. The control switch receives a control signal to determine whether a predetermined current flows through the corresponding electrical fuse and breaks the electrical fuse. The resistant device is coupled between a bulk terminal and a source terminal to increase a resistance of a parasitic channel, such that an electrostatic discharge (ESD) protection is enhanced, and errors of final test trimming of an IC chip are avoided.
    Type: Application
    Filed: January 25, 2012
    Publication date: May 9, 2013
    Inventors: LI-WEN FANG, Chih-Hao Yang, An-Tung Chen
  • Publication number: 20120019218
    Abstract: The present invention discloses a constant on-time switching regulator, a control method therefor, and an on-time calculation circuit for calculating an on-time period of a constant on-time switching regulator. The on-time calculation circuit calculates on-time according to practical conditions. It includes: a driver gate receiving a gate signal of a power switch in a switching regulator, the driver gate operating between high and low levels of a first reference voltage and ground; a low pass filter receiving an output from the driver gate and generating a second reference voltage, a ratio between the second reference voltage and the first reference voltage being substantially the same as a duty ratio of the gate signal; and an on-time generator comparing the second reference voltage with a ramp signal to determine an on-time of the power switch.
    Type: Application
    Filed: April 19, 2011
    Publication date: January 26, 2012
    Inventors: Li-Wen Fang, Ting-Jung Tai, Chih-Hao Yang
  • Publication number: 20120019219
    Abstract: The present invention discloses a constant on-time switching regulator, a control method therefor, and an on-time calculation circuit for calculating an on-time period of a constant on-time switching regulator. The on-time calculation circuit calculates on-time according to practical conditions. It includes: a driver gate receiving a gate signal of a power switch in a switching regulator, the driver gate operating between high and low levels of a first reference voltage and ground; a low pass filter receiving an output from the driver gate and generating a second reference voltage, a ratio between the second reference voltage and the first reference voltage being substantially the same as a duty ratio of the gate signal; and an on-time generator comparing the second reference voltage with a ramp signal to determine an on-time of the power switch.
    Type: Application
    Filed: July 20, 2011
    Publication date: January 26, 2012
    Inventors: Li-Wen Fang, Ting-Jung Tai, Chih-Hao Yang
  • Publication number: 20110018514
    Abstract: The present invention discloses a dual-mode buck switching regulator, comprising: a first power transistor having an end coupled to an input voltage and another end coupled to a common node; an inductor having an end coupled to the common node and another end coupled to the input voltage; a second power transistor having an end coupled to ground; a diode having an end coupled to ground; and a control circuit generating a first and a second switch control signals for controlling operations of the first and the second power transistors according to a feedback signal, and generating a mode selection signal according a mode control signal to select a synchronous or an asynchronous mode, wherein the second power transistor has another end which is coupled to the common node in the synchronous mode, and the diode has another end which is coupled to the common node in the asynchronous mode, and in the asynchronous mode: the another end of the second power transistor is not coupled to the common mode, or the second p
    Type: Application
    Filed: February 12, 2010
    Publication date: January 27, 2011
    Inventors: An-Tung Chen, Li-Wen Fang
  • Patent number: 7839197
    Abstract: A level shift circuit includes an input stage and an output stage coupled to each other by two nodes. The input stage changes the voltages on the nodes according to an input signal, and the output stage determines an output signal according to the voltages on the two nodes. In a transition state, the input stage provides a large current to charge or discharge the first node or the second node so as to quickly change the voltage thereon. In a steady state, the input stage lowers the current so as to reduce power consumption.
    Type: Grant
    Filed: September 9, 2008
    Date of Patent: November 23, 2010
    Assignee: Richtek Technology Corp.
    Inventors: An-Tung Chen, Li-Wen Fang, Hung-Der Su
  • Publication number: 20090066399
    Abstract: A level shift circuit includes an input stage and an output stage coupled to each other by two nodes. The input stage changes the voltages on the nodes according to an input signal, and the output stage determines an output signal according to the voltages on the two nodes. In a transition state, the input stage provides a large current to charge or discharge the first node or the second node so as to quickly change the voltage thereon. In a steady state, the input stage lowers the current so as to reduce power consumption.
    Type: Application
    Filed: September 9, 2008
    Publication date: March 12, 2009
    Inventors: An-Tung Chen, Li-Wen Fang, Hung-Der Su