Patents by Inventor Chien-Ping Lu

Chien-Ping Lu 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: 8169159
    Abstract: A LED driver is disclosed for providing a current for LED lighting. The LED driver includes an inductor and a controller having a power switch, and the inductor, the power switch and a LED to be driven are configured to be an asynchronous boost converter. Because the driven LED serves as a rectifier diode of the asynchronous boost converter, the controller may have fewer components and requires smaller die area.
    Type: Grant
    Filed: September 23, 2008
    Date of Patent: May 1, 2012
    Assignee: Richtek Technology Corp.
    Inventors: Chien-Ping Lu, Wei-Hsin Wei, Kwan-Jen Chu, Tzu-Huan Chiu
  • 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: 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
  • Patent number: 7940596
    Abstract: A switching regulator includes a low-side switch having a body diode. During the low-side switch is on, a zero-current sense circuit monitors the inductor current of the switching regulator and triggers a signal to turn off the low-side switch when the inductor current falls down to a zero-current threshold, to prevent reverse inductor current from the output terminal of the switching regulator. A body-diode turn-on time controller monitors the turn-on time of the body diode and adjusts the zero-current threshold according thereto, and the turn-on time of the body diode can be reduced to an optimal interval subsequently. The self-adjustable zero-current threshold is adaptive according to the application conditions, such as the inductor size, input voltage and output voltage of the switching regulator.
    Type: Grant
    Filed: November 3, 2009
    Date of Patent: May 10, 2011
    Assignee: Richtek Technology Corp.
    Inventors: Kwan-Jen Chu, Nien-Hui Kung, Tzu-Huan Chiu, Chien-Ping Lu
  • Publication number: 20110050192
    Abstract: Methods are proposed for a buck boost voltage regulator to monitor the output voltage or both the inductor current and the output voltage of the buck boost voltage regulator to control the buck boost voltage regulator to reduce the switching times of the power switches of the buck boost voltage regulator to improve the light load efficiency of the buck boost voltage regulator.
    Type: Application
    Filed: August 24, 2010
    Publication date: March 3, 2011
    Applicant: RICHTEK TECHNOLOGY CORP.
    Inventors: TZU-HUAN CHIU, KWAN-JEN CHU, CHIEN-PING LU, WEI-HSIN WEI
  • Publication number: 20110001461
    Abstract: The present invention discloses a buck-boost switching regulator, and a control circuit and a method therefor, to convert an input voltage to an output voltage. The control method comprises: obtaining a feedback signal relating to the output voltage; comparing the feedback signal with a reference voltage to generate an error amplified signal; when the error amplified signal is between a first voltage (V1) and a second voltage (V2), causing the switching regulator to operate in a buck conversion mode; when the error amplified signal is between a third voltage (V3) and a fourth voltage (V4), causing the switching regulator to operate in a boost conversion mode; and when the error amplified signal is between the second voltage and the third voltage, causing the switching regulator to operate in a buck-boost conversion mode in which each power switch operates according to a respective predetermined pulse width, wherein V1<V2<V3<V4.
    Type: Application
    Filed: April 19, 2010
    Publication date: January 6, 2011
    Inventors: Chien-Ping LU, Kwan-Jen CHU, Tzu-Huan CHIU
  • Patent number: 7779191
    Abstract: A system and method for transitions a computing system between operating modes that have different power consumption characteristics. When a system management unit (SMU) determines that the computing system is in a low activity state, the SMU transitions the central processing unit (CPU) into a low power operating mode after the CPU stores critical operating state of the CPU in a memory. The SMU then intercepts and processes interrupts intended for the CPU, modifying a copy of the critical operating state. This effectively extends the time during which the CPU stays in lower power mode. When the SMU determines that the computing system exits a low activity state, the copy of the critical operating state is stored in the memory and the SMU transitions the CPU into a high power operating mode using the modified critical operating state.
    Type: Grant
    Filed: July 29, 2008
    Date of Patent: August 17, 2010
    Assignee: NVIDIA Corporation
    Inventors: Chien-Ping Lu, Stephen D. Lew, Robert William Chapman
  • Patent number: 7714556
    Abstract: A quick response switching regulator comprises a power stage having a pair of high-side switch and low-side switch and an inductor connected together by a switching node, a feedback circuit for producing a feedback signal, and a control circuit producing control signals with reference to the feedback signal to control the pair of high-side switch and low-side switch. The feedback circuit is connected to the switching node to shorten the feedback path and speed up the response. The control circuit further monitors the current flowing through the inductor to keep the low-side switch off before the peak of the inductor current becomes higher than a value.
    Type: Grant
    Filed: August 29, 2007
    Date of Patent: May 11, 2010
    Assignee: Richtek Technology Corp.
    Inventors: Kwan-Jen Chu, Tzu-Huan Chiu, Nien-Hui Kung, Chien-Ping Lu
  • Patent number: 7696806
    Abstract: The present invention discloses a level shift circuit which comprises: an input driver circuit; a capacitor having a first end electrically connected with the output of the input driver circuit; an output driver circuit electrically connected with a second end of the capacitor; and a feedback latch circuit electrically connected between the output of the output driver circuit and the second end of the capacitor, for maintaining the voltage level at the second end of the capacitor.
    Type: Grant
    Filed: February 21, 2008
    Date of Patent: April 13, 2010
    Assignee: Richtek Technology Corporation
    Inventors: Kwan-Jen Chu, Chien-Ping Lu
  • Publication number: 20100072915
    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: Application
    Filed: April 1, 2009
    Publication date: March 25, 2010
    Inventors: Kwan-Jen Chu, Nien-Hui Kung, Tzu-Huan Chiu, Chien-Ping Lu
  • Publication number: 20100066312
    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: Application
    Filed: March 10, 2009
    Publication date: March 18, 2010
    Inventors: Chien-Ping Lu, Nien-Hui Kung, Li-Wei Lee, Kwan-Jen Chu, Ying-Hsin Hsing, Chun-Tsung Chen
  • Publication number: 20100052629
    Abstract: A switching regulator includes a low-side switch having a body diode. During the low-side switch is on, a zero-current sense circuit monitors the inductor current of the switching regulator and triggers a signal to turn off the low-side switch when the inductor current falls down to a zero-current threshold, to prevent reverse inductor current from the output terminal of the switching regulator. A body-diode turn-on time controller monitors the turn-on time of the body diode and adjusts the zero-current threshold according thereto, and the turn-on time of the body diode can be reduced to an optimal interval subsequently. The self-adjustable zero-current threshold is adaptive according to the application conditions, such as the inductor size, input voltage and output voltage of the switching regulator.
    Type: Application
    Filed: November 3, 2009
    Publication date: March 4, 2010
    Inventors: Kwan-Jen Chu, Nien-Hui Kung, Tzu-Huan Chiu, Chien-Ping Lu
  • Publication number: 20100031071
    Abstract: A system and method for transitions a computing system between operating modes that have different power consumption characteristics. When a system management unit (SMU) determines that the computing system is in a low activity state, the SMU transitions the central processing unit (CPU) into a low power operating mode after the CPU stores critical operating state of the CPU in a memory. The SMU then intercepts and processes interrupts intended for the CPU, modifying a copy of the critical operating state. This effectively extends the time during which the CPU stays in lower power mode. When the SMU determines that the computing system exits a low activity state, the copy of the critical operating state is stored in the memory and the SMU transitions the CPU into a high power operating mode using the modified critical operating state.
    Type: Application
    Filed: July 29, 2008
    Publication date: February 4, 2010
    Inventors: Chien-Ping LU, Stephen D. Lew, Robert William Chapman
  • Publication number: 20100019682
    Abstract: A LED driver is disclosed for providing a current for LED lighting. The LED driver includes an inductor and a controller having a power switch, and the inductor, the power switch and a LED to be driven are configured to be an asynchronous boost converter. Because the driven LED serves as a rectifier diode of the asynchronous boost converter, the controller may have fewer components and requires smaller die area.
    Type: Application
    Filed: September 23, 2008
    Publication date: January 28, 2010
    Inventors: Chien-Ping Lu, Wei-Hsin Wei, Kwan-Jen Chu, Tzu-Huan Chiu
  • Patent number: 7652945
    Abstract: A switching regulator includes a low-side switch having a body diode. During the low-side switch is on, a zero-current sense circuit monitors the inductor current of the switching regulator and triggers a signal to turn off the low-side switch when the inductor current falls down to a zero-current threshold, to prevent reverse inductor current from the output terminal of the switching regulator. A body-diode turn-on time controller monitors the turn-on time of the body diode and adjusts the zero-current threshold according thereto, and the turn-on time of the body diode can be reduced to an optimal interval subsequently. The self-adjustable zero-current threshold is adaptive according to the application conditions, such as the inductor size, input voltage and output voltage of the switching regulator.
    Type: Grant
    Filed: March 31, 2008
    Date of Patent: January 26, 2010
    Assignee: Richtek Technology Corp.
    Inventors: Kwan-Jen Chu, Nien-Hui Kung, Tzu-Huan Chiu, Chien-Ping Lu
  • Publication number: 20090212841
    Abstract: The present invention discloses a level shift circuit which comprises: an input driver circuit; a capacitor having a first end electrically connected with the output of the input driver circuit; an output driver circuit electrically connected with a second end of the capacitor; and a feedback latch circuit electrically connected between the output of the output driver circuit and the second end of the capacitor, for maintaining the voltage level at the second end of the capacitor.
    Type: Application
    Filed: February 21, 2008
    Publication date: August 27, 2009
    Inventors: Kwan-Jen Chu, Chien-Ping Lu
  • Publication number: 20080246455
    Abstract: A switching regulator includes a low-side switch having a body diode. During the low-side switch is on, a zero-current sense circuit monitors the inductor current of the switching regulator and triggers a signal to turn off the low-side switch when the inductor current falls down to a zero-current threshold, to prevent reverse inductor current from the output terminal of the switching regulator. A body-diode turn-on time controller monitors the turn-on time of the body diode and adjusts the zero-current threshold according thereto, and the turn-on time of the body diode can be reduced to an optimal interval subsequently. The self-adjustable zero-current threshold is adaptive according to the application conditions, such as the inductor size, input voltage and output voltage of the switching regulator.
    Type: Application
    Filed: March 31, 2008
    Publication date: October 9, 2008
    Inventors: Kwan-Jen Chu, Nien-Hui Kung, Tzu-Huan Chiu, Chien-Ping Lu
  • Publication number: 20080211470
    Abstract: The present invention discloses an auto discharge linear regulator comprising: a basic linear regulator for converting an input voltage to an output voltage at an output node; a load detector circuit for detecting the load condition at the output node; and an discharge control circuit under control by the load detector circuit for discharging the voltage at the output node.
    Type: Application
    Filed: February 13, 2008
    Publication date: September 4, 2008
    Inventors: Tzu-Huan Chiu, Kwan-Jen Chu, Chien-Ping Lu
  • Publication number: 20080174286
    Abstract: A quick response switching regulator comprises a power stage having a pair of high-side switch and low-side switch and an inductor connected together by a switching node, a feedback circuit for producing a feedback signal, and a control circuit producing control signals with reference to the feedback signal to control the pair of high-side switch and low-side switch. The feedback circuit is connected to the switching node to shorten the feedback path and speed up the response. The control circuit further monitors the current flowing through the inductor to keep the low-side switch off before the peak of the inductor current becomes higher than a value.
    Type: Application
    Filed: August 29, 2007
    Publication date: July 24, 2008
    Inventors: Kwan-Jen Chu, Tzu-Huan Chiu, Nien-Hui Kung, Chien-Ping Lu
  • Patent number: 6230177
    Abstract: The method and apparatus employ a texture filter in a graphics processor to perform a transform such as, for example, a Fast Fourier Transform. The texturizer can include an array of linear interpolators. The architecture reduces the computational complexity of the transform processes.
    Type: Grant
    Filed: June 12, 1998
    Date of Patent: May 8, 2001
    Assignee: Silicon Graphics, Inc.
    Inventors: Carroll Philip Gossett, Nancy Cam Winget, Chien-Ping Lu