Patents by Inventor Kwan-Jen Chu

Kwan-Jen Chu 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: 20090096434
    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: Application
    Filed: September 30, 2008
    Publication date: April 16, 2009
    Inventors: Nien-Hui Kung, Kwan-Jen Chu
  • Patent number: 7518888
    Abstract: In a fly-back voltage converter that includes a transformer to transform a primary current to a secondary current and a switch serially coupled to the primary winding to switch the primary current in response to a control signal, a detection signal is produced by comparing the secondary current with two threshold values after the primary current is switched off to trigger the next on-time cycle of the switch. Once the secondary current is detected to be greater than a first threshold value, it is determined that the secondary current has been switched on, and until the secondary current is detected to be lower than a second threshold value, it is determined that the secondary current is to be switched off. The hysteresis range of the threshold values prevents error detection of the secondary current.
    Type: Grant
    Filed: May 2, 2006
    Date of Patent: April 14, 2009
    Assignee: Richtek Technology Corp.
    Inventors: Kwan-Jen Chu, Chung-Lung Pai, Yuan-Huang Cheng, Jing-Meng Liu
  • Publication number: 20090027027
    Abstract: The phase node voltage or the PWM signal in an asynchronous boost converter is monitored to detect a phase node voltage ringing. When a phase node voltage ringing is detected, a detection signal is asserted to establish a bypass path to bypass the inductor of the converter. A charge bypass circuit is shunt to the inductor, and controlled by the detection signal to establish the bypass path. Due to the bypass path, the phase node voltage is maintained at a constant, and the phase node voltage radiation and input/output noise are eliminated.
    Type: Application
    Filed: July 24, 2008
    Publication date: January 29, 2009
    Inventors: Shui-Mu Lin, Jien-Sheng Chen, Kwan-Jen Chu, Tsung-Wei Huang, Chao-Hsuan Chuang
  • Publication number: 20080310198
    Abstract: An apparatus and method are provided for suppressing the input current inrush for a voltage converter in a pre-charge stage. The voltage converter comprises a power input for receiving an input current, a power output for supplying an output voltage for a load, and an output capacitor connected to the power output. In a pre-charge stage, a current limiting device is connected between the power input and the output capacitor to limit the input current to flow therethrough, and a variable current limiting control circuit provides a control signal to the current limiting device to determine a variable maximum value for the input current.
    Type: Application
    Filed: July 13, 2007
    Publication date: December 18, 2008
    Inventors: Yun-Chi Chiang, Kwan-Jen Chu, Jien-Sheng Chen
  • 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: 20080211465
    Abstract: A soft-stop circuit and method are provided for a voltage regulator which converts a battery voltage to an output voltage according to a feedback voltage derived from the output voltage and a reference voltage, to control the voltage regulator to enter a soft-stop state when the battery voltage is lower than a threshold level, and in which state, and the output voltage is controlled to decrease so as for the battery voltage to have a slower decreasing speed and in turn a longer battery lifetime.
    Type: Application
    Filed: February 26, 2008
    Publication date: September 4, 2008
    Inventors: Nien-Hui Kung, Kwan-Jen Chu
  • Patent number: 7411379
    Abstract: In an apparatus for over-voltage and over-current protection for a step-up current-mode converter including an inductor connected via a phase node to a switch that is switched by a control signal to convert an input voltage to an output voltage, a controller has a multiplexed pin, and a resistor and a capacitor are connected in parallel between the multiplexed pin and the phase node. In an over-voltage protection mode, the controller senses the voltage on the multiplexed pin, and in an over-current protection mode, the controller supplies a current to flow through the resistor and senses the voltage on the multiplexed pin.
    Type: Grant
    Filed: December 19, 2005
    Date of Patent: August 12, 2008
    Assignee: Richtek Technology Corp.
    Inventors: Kwan-Jen Chu, Chung-Lung Pai, Chun-Chin Tung, Jing-Meng Liu
  • 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
  • Publication number: 20080074092
    Abstract: The present invention discloses a switching regulator, and a control circuit and a control method therefor. The switching regulator comprises two transistors, and the two transistors are never simultaneously OFF.
    Type: Application
    Filed: August 17, 2007
    Publication date: March 27, 2008
    Inventors: Nien-Hui Kung, Kwan-Jen Chu
  • Patent number: 7170763
    Abstract: In a capacitor charger, a transformer has a primary winding connected between an input voltage and a switch for generating a primary current flowing through the primary winding by switching the switch to thereby induce a secondary current flowing through a secondary winding of the transformer and a secondary voltage tapered from the secondary winding, a control apparatus and method adjusts the on-time period for the switch in response to the input voltage. The charging time and charging current are independent of the input voltage, and there is no power loss resulted from current sense to the primary current.
    Type: Grant
    Filed: December 14, 2004
    Date of Patent: January 30, 2007
    Assignee: Richtek Technology Corp.
    Inventors: Chung-Lung Pai, Kwan-Jen Chu, Chun-Yen Huang, Jing-Meng Liu
  • Patent number: 7148666
    Abstract: A direct current voltage boosting/bucking device includes a direct current voltage boosting circuit and a low drop-out (LDO) linear voltage converting circuit. The direct current voltage boosting circuit boosts an input voltage so as to generate an output voltage higher than the input voltage. The LDO linear voltage converting circuit converts the output voltage into a load voltage that is to be provided to a load, and controls the direct current voltage boosting circuit in accordance with a feedback signal from the load such that the output voltage and the load voltage have a minimum drop-out voltage differential therebetween and such that current flow through the load is maintained at a determined level.
    Type: Grant
    Filed: July 18, 2005
    Date of Patent: December 12, 2006
    Assignee: Richtek Technology Corp.
    Inventors: Liang-Pin Tai, Chun-Tsung Chen, Chin-Chiang Yeh, Po-Shun Chung, Kwan-Jen Chu, Chung-Lung Pai
  • Publication number: 20060268974
    Abstract: A pulse width modulation (PWM) Regulator System with automatically switching pulse skipping mode (PSM) is disclosed. The PWM regulator system comprises a PWM regulator, a PSM switching module and a pulse generator. The PWM regulator converts the input voltage by PWM. The PSM switching module determines to enter or exit the PSM. The pulse generator adaptively produces pulse signal for the switching regulator to operate in PSM.
    Type: Application
    Filed: November 15, 2005
    Publication date: November 30, 2006
    Inventors: Kwan-Jen Chu, Chung-Lung Pai, Po-Shun Chung, Jing-Meng Liu
  • Publication number: 20060261790
    Abstract: A direct current voltage boosting/bucking device includes a direct current voltage boosting circuit and a low drop-out (LDO) linear voltage converting circuit. The direct current voltage boosting circuit boosts an input voltage so as to generate an output voltage higher than the input voltage. The LDO linear voltage converting circuit converts the output voltage into a load voltage that is to be provided to a load, and controls the direct current voltage boosting circuit in accordance with a feedback signal from the load such that the output voltage and the load voltage have a minimum drop-out voltage differential therebetween and such that current flow through the load is maintained at a determined level.
    Type: Application
    Filed: July 18, 2005
    Publication date: November 23, 2006
    Inventors: Liang-Pin Tai, Chun-Tsung Chen, Chin-Chiang Yeh, Po-Shun Chung, Kwan-Jen Chu, Chung-Lung Pai
  • Publication number: 20060250827
    Abstract: In a fly-back voltage converter that includes a transformer to transform a primary current to a secondary current and a switch serially coupled to the primary winding to switch the primary current in response to a control signal, a detection signal is produced by comparing the secondary current with two threshold values after the primary current is switched off to trigger the next on-time cycle of the switch. Once the secondary current is detected to be greater than a first threshold value, it is determined that the secondary current has been switched on, and until the secondary current is detected to be lower than a second threshold value, it is determined that the secondary current is to be switched off. The hysteresis range of the threshold values prevents error detection of the secondary current.
    Type: Application
    Filed: May 2, 2006
    Publication date: November 9, 2006
    Inventors: Kwan-Jen Chu, Chung-Lung Pai, Yuan-Huang Cheng, Jing-Meng Liu
  • Publication number: 20060132997
    Abstract: In an apparatus for over-voltage and over-current protection for a step-up current-mode converter including an inductor connected via a phase node to a switch that is switched by a control signal to convert an input voltage to an output voltage, a controller has a multiplexed pin, and a resistor and a capacitor are connected in parallel between the multiplexed pin and the phase node. In an over-voltage protection mode, the controller senses the voltage on the multiplexed pin, and in an over-current protection mode, the controller supplies a current to flow through the resistor and senses the voltage on the multiplexed pin.
    Type: Application
    Filed: December 19, 2005
    Publication date: June 22, 2006
    Inventors: Kwan-Jen Chu, Chung-Lung Pai, Chun-Chin Tung, Jing-Meng Liu
  • Patent number: 7062738
    Abstract: This invention provides a compiler, circuits and a method for generating a flash memory for integrated circuits. This invention provides a flash memory compiler which can generate flexible configurations which are a function of the flash memory array bit count. In addition, this flash compiler of this invention has the ability to optimize the resultant flash memories so as to produce the correct amount of flash array current driving capability and minimal wasting of power dissipation as a function of the flash memory array size.
    Type: Grant
    Filed: July 25, 2002
    Date of Patent: June 13, 2006
    Assignee: Taiwan Semiconductor Manufacturing Company
    Inventors: Kwan-Jen Chu, Hung-Chang Yu
  • Publication number: 20050140340
    Abstract: In a capacitor charger including a transformer having a primary winding connected with an input voltage and a secondary winding for transforming a primary current flowing through the primary winding to a secondary current flowing through the secondary winding, the primary current is adjusted according to a monitoring voltage varying with the input voltage, thereby prolonging the lifetime of the battery that provides the input voltage and improving the power efficiency of the battery.
    Type: Application
    Filed: December 22, 2004
    Publication date: June 30, 2005
    Inventors: Chung-Lung Pai, Kwan-Jen Chu, Chun-Yen Huang, Jing-Meng Liu
  • Publication number: 20050134235
    Abstract: In a capacitor charger, a transformer has a primary winding connected between an input voltage and a switch for generating a primary current flowing through the primary winding by switching the switch to thereby induce a secondary current flowing through a secondary winding of the transformer and a secondary voltage tapered from the secondary winding, a control apparatus and method adjusts the on-time period for the switch in response to the input voltage. The charging time and charging current are independent of the input voltage, and there is no power loss resulted from current sense to the primary current.
    Type: Application
    Filed: December 14, 2004
    Publication date: June 23, 2005
    Inventors: Chung-Lung Pai, Kwan-Jen Chu, Chun-Yen Huang, Jing-Meng Liu
  • Patent number: 6639847
    Abstract: A method and apparatus for stabilizing a sense amplifier utilized in a memory array of a semiconductor integrated circuit. A memory cell of the memory array may be selected, wherein the selected memory cell is associated with a sense amplifier. A cell current associated with the selected memory cell and a reference current associated with a reference memory cell can be generated. Thereafter, the reference current may be synchronized with a plurality of address inputs to eliminate a source line resistance associated with the selected memory cell, thereby resulting in a stabilization the sense amplifier by the elimination of associated address sensitivity.
    Type: Grant
    Filed: June 26, 2002
    Date of Patent: October 28, 2003
    Assignee: Taiwan Semiconductor Manufacturing Co. Ltd
    Inventor: Kwan-Jen Chu