Patents by Inventor Enzhu Liang

Enzhu Liang 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: 20210091657
    Abstract: A multi-phase power supply includes a plurality of phase controllers each driving a first terminal of a respective inductor alternatively between an input voltage and a ground voltage to regulate an output voltage in a work mode, keeping the first terminal of the respective inductor in a high impedance state during a non-work mode, having an input for receiving an enable signal for selecting between the work mode and the non-work mode, and generating a current monitor signal to represent a current through the respective inductor during both the work mode and the non-work mode, and a controller coupled to each phase controller for selectively enabling respective ones of the phase controllers in response to a load demand, receiving the current monitor signal from each phase controller, and selectively shutting down the multi-phase power supply when a total of current monitor signals from the phase controller exceeds a threshold.
    Type: Application
    Filed: December 2, 2020
    Publication date: March 25, 2021
    Applicant: FAIRCHILD SEMICONDUCTOR CORPORATION
    Inventors: Enzhu LIANG, Kaiwei YAO, Ming GU
  • Patent number: 10886833
    Abstract: A switch mode power supply controller includes a switch terminal adapted to be coupled to an inductor that drives a load, high- and low-side switches a pulse width modulation (PWM) circuit, and a current monitor circuit. The PWM circuit is coupled to a feedback terminal for receiving a feedback signal, and alternatively drives the high-side switch and the low-side switch with a duty cycle set using the feedback signal to regulate an output voltage to a desired level in a work mode, and keeps both the high-side switch and the low-side switch non-conductive in a non-work mode. The current monitor circuit provides a current monitor signal representative of a current driven from the inductor to the load, wherein the current monitor circuit forms the current monitor signal by measuring an inductor current during a work mode, and by emulating the inductor current during a non-work mode.
    Type: Grant
    Filed: May 1, 2017
    Date of Patent: January 5, 2021
    Assignee: FAIRCHILD SEMICONDUCTOR CORPORATION
    Inventors: Enzhu Liang, Kaiwei Yao, Ming Gu
  • Patent number: 10448480
    Abstract: The embodiments disclosed herein describe a set of fault detection circuits for LED circuits in an LED channel. A first fault detection circuit is configured to detect a short fault across one or more LEDs. A second fault detection circuit is configured to detect an open fault across an LED. A third fault detection circuit is configured to detect a short across an LED channel transistor. A fourth fault detection circuit is configured to detect an LED channel sense resistor open fault. A fifth fault detection circuit is configured to detect if the LED channel is being intentionally unused. These fault detect circuits can be implemented in a fault detection integrated circuit coupled to the LED channel.
    Type: Grant
    Filed: May 10, 2018
    Date of Patent: October 15, 2019
    Assignee: Dialog Semiconductor Inc.
    Inventors: Enzhu Liang, Yuwen Wang, Ming Gu
  • Publication number: 20180263088
    Abstract: The embodiments disclosed herein describe a set of fault detection circuits for LED circuits in an LED channel. A first fault detection circuit is configured to detect a short fault across one or more LEDs. A second fault detection circuit is configured to detect an open fault across an LED. A third fault detection circuit is configured to detect a short across an LED channel transistor. A fourth fault detection circuit is configured to detect an LED channel sense resistor open fault. A fifth fault detection circuit is configured to detect if the LED channel is being intentionally unused. These fault detect circuits can be implemented in a fault detection integrated circuit coupled to the LED channel.
    Type: Application
    Filed: May 10, 2018
    Publication date: September 13, 2018
    Inventors: Enzhu Liang, Yuwen Wang, Ming Gu
  • Patent number: 9999110
    Abstract: The embodiments disclosed herein describe a set of fault detection circuits for LED circuits in an LED channel. A first fault detection circuit is configured to detect a short fault across one or more LEDs. A second fault detection circuit is configured to detect an open fault across an LED. A third fault detection circuit is configured to detect a short across an LED channel transistor. A fourth fault detection circuit is configured to detect an LED channel sense resistor open fault. A fifth fault detection circuit is configured to detect if the LED channel is being intentionally unused. These fault detect circuits can be implemented in a fault detection integrated circuit coupled to the LED channel.
    Type: Grant
    Filed: June 16, 2014
    Date of Patent: June 12, 2018
    Assignee: Dialog Semiconductor Inc.
    Inventors: Enzhu Liang, Yuwen Wang, Ming Gu
  • Publication number: 20170346385
    Abstract: A switch mode power supply controller includes a switch terminal adapted to be coupled to an inductor that drives a load, high- and low-side switches a pulse width modulation (PWM) circuit, and a current monitor circuit. The PWM circuit is coupled to a feedback terminal for receiving a feedback signal, and alternatively drives the high-side switch and the low-side switch with a duty cycle set using the feedback signal to regulate an output voltage to a desired level in a work mode, and keeps both the high-side switch and the low-side switch non-conductive in a non-work mode. The current monitor circuit provides a current monitor signal representative of a current driven from the inductor to the load, wherein the current monitor circuit forms the current monitor signal by measuring an inductor current during a work mode, and by emulating the inductor current during a non-work mode.
    Type: Application
    Filed: May 1, 2017
    Publication date: November 30, 2017
    Applicant: FAIRCHILD SEMICONDUCTOR CORPORATION
    Inventors: Enzhu LIANG, Kaiwei YAO, Ming GU
  • Patent number: 9351370
    Abstract: An LED (Light Emitting Diode) controller comprises a first LED driver to generate a first PWM (Pulse Width Modulation) drive signal to turn on or turn off, respectively, a first current through a first LED string. Additionally, the LED controller comprises a compensation circuit to generate the first PWM drive signal responsive to a first duty set signals. The first duty set signal is indicative of a first duty cycle set for the first PWM drive signal. The compensation circuit receives a first feedback signal indicative of the first current, generates a first error signal indicative of a difference between a first predetermined target value and the first feedback signal, and generates the first PWM drive signal to have the first duty cycle corresponding to the first duty set signal and further adjusted by the first error signal.
    Type: Grant
    Filed: September 12, 2014
    Date of Patent: May 24, 2016
    Assignee: Dialog Semiconductor Inc.
    Inventors: Andrey B. Malinin, Enzhu Liang, Yuwen Wang
  • Publication number: 20160081148
    Abstract: The embodiments disclosed herein describe a set of fault detection circuits for LED circuits in an LED channel. A first fault detection circuit is configured to detect a short fault across one or more LEDs. A second fault detection circuit is configured to detect an open fault across an LED. A third fault detection circuit is configured to detect a short across an LED channel transistor. A fourth fault detection circuit is configured to detect an LED channel sense resistor open fault. A fifth fault detection circuit is configured to detect if the LED channel is being intentionally unused. These fault detect circuits can be implemented in a fault detection integrated circuit coupled to the LED channel.
    Type: Application
    Filed: June 16, 2014
    Publication date: March 17, 2016
    Inventors: Enzhu Liang, Yuwen Wang, Ming Gu
  • Patent number: 9161402
    Abstract: An LED driver controls current through an LED string. The LED driver generates a boosted PWM signal to drive a PWM transistor in the LED current path such that the PWM transistor maintains a substantially constant VGS, thus minimizing turn-on impedance of the PWM transistor. A current mirror circuit controls peak LED current when the PWM transistor is on. A trimming circuit includes a set of programmable switches to couple or decouple trimming transistor from the LED current path, and allowing for fine calibration of the LED current. By maintaining a low resistance and compensating for current mismatch in the LED current path, the LED driver provides efficient power performance and robustness that is particularly beneficial in high current applications.
    Type: Grant
    Filed: March 31, 2014
    Date of Patent: October 13, 2015
    Assignee: Dialog Semiconductor Inc.
    Inventors: Minjong Kim, Enzhu Liang, Xuecheng Jin
  • Publication number: 20150076999
    Abstract: An LED (Light Emitting Diode) controller comprises a first LED driver to generate a first PWM (Pulse Width Modulation) drive signal to turn on or turn off, respectively, a first current through a first LED string. Additionally, the LED controller comprises a compensation circuit to generate the first PWM drive signal responsive to a first duty set signals. The first duty set signal is indicative of a first duty cycle set for the first PWM drive signal. The compensation circuit receives a first feedback signal indicative of the first current, generates a first error signal indicative of a difference between a first predetermined target value and the first feedback signal, and generates the first PWM drive signal to have the first duty cycle corresponding to the first duty set signal and further adjusted by the first error signal.
    Type: Application
    Filed: September 12, 2014
    Publication date: March 19, 2015
    Inventors: Andrey B. Malinin, Enzhu Liang, Yuwen Wang
  • Publication number: 20140210365
    Abstract: An LED driver controls current through an LED string. The LED driver generates a boosted PWM signal to drive a PWM transistor in the LED current path such that the PWM transistor maintains a substantially constant VGS, thus minimizing turn-on impedance of the PWM transistor. A current mirror circuit controls peak LED current when the PWM transistor is on. A trimming circuit includes a set of programmable switches to couple or decouple trimming transistor from the LED current path, and allowing for fine calibration of the LED current. By maintaining a low resistance and compensating for current mismatch in the LED current path, the LED driver provides efficient power performance and robustness that is particularly beneficial in high current applications.
    Type: Application
    Filed: March 31, 2014
    Publication date: July 31, 2014
    Applicant: Dialog Semiconductor Inc.
    Inventors: Minjong Kim, Enzhu Liang, Xuecheng Jin
  • Patent number: 8791647
    Abstract: A system controls a switching power converter to power LED strings using a predictive feedforward control mechanism. An LED controller determines programmed current levels and duty cycles for driving LED strings. The LED controller determines a predicted load for a subsequent cycle of a switching power converter driving the LED strings based on the programmed current levels and duty cycles. A power conversion controller uses the predicted load information to control switching of the switching power converter. This improves the dynamic response of the switching converter to changing load conditions, thereby improving overall power efficiency and performance of the system.
    Type: Grant
    Filed: December 28, 2011
    Date of Patent: July 29, 2014
    Assignee: Dialog Semiconductor Inc.
    Inventors: John William Kesterson, Xiaoyan Wang, Xuecheng Jin, Enzhu Liang, Selcuk Sen
  • Patent number: 8710752
    Abstract: A system that provides an intelligent approach to driving multiple strings of LEDs. A processing device determines an optimal current level for each LED string from a limited set of allowed currents. The processing device also determines a PWM duty cycle for driving the LEDs in each LED string to provide precise brightness control over the LED string. The settings for the current level and duty cycle are transmitted to an LED driver for regulating the current and on-off times of the LED strings. Beneficially, the system reduces the size of the LED driver while leveraging existing resources available in the processing device to operate the LEDs in a power efficient manner.
    Type: Grant
    Filed: March 3, 2011
    Date of Patent: April 29, 2014
    Assignee: Dialog Semiconductor Inc.
    Inventors: Xuecheng Jin, Minjong Kim, Enzhu Liang, John William Kesterson, Xiaoyan Wang
  • Patent number: 8710753
    Abstract: An LED driver controls current through an LED string. The LED driver generates a boosted PWM signal to drive a PWM transistor in the LED current path such that the PWM transistor maintains a substantially constant VGS, thus minimizing turn-on impedance of the PWM transistor. A current mirror circuit controls peak LED current when the PWM transistor is on. A trimming circuit includes a set of programmable switches to couple or decouple trimming transistor from the LED current path, and allowing for fine calibration of the LED current. By maintaining a low resistance and compensating for current mismatch in the LED current path, the LED driver provides efficient power performance and robustness that is particularly beneficial in high current applications.
    Type: Grant
    Filed: December 7, 2011
    Date of Patent: April 29, 2014
    Assignee: Dialog Semiconductor Inc.
    Inventors: Minjong Kim, Enzhu Liang, Xuecheng Jin
  • Patent number: 8581568
    Abstract: A start-up circuit in a switch-mode power converter that employs a Zener diode to provide a reference voltage to reduce the power consumption and the size of the start-up circuit. The start-up circuit also includes a coarse current source and a coarse reference voltage signal generator for producing current and reference voltage for initial startup operation of a bandgap circuit. The reference signal and current from coarse current source and the reference voltage signal generator are subject to large process, voltage and temperature (PVT) variations or susceptible to noise from the power supply, and hence, these signals are used temporarily during start-up and replaced with signals from higher performance components. After bandgap circuit becomes operational, the start-up receives voltage reference signal from the bandgap circuit to more accurately detect undervoltage lockout conditions.
    Type: Grant
    Filed: October 19, 2010
    Date of Patent: November 12, 2013
    Assignee: iWatt Inc.
    Inventors: Enzhu Liang, Jiang Chen, Xuecheng Jin
  • Publication number: 20130169172
    Abstract: A system controls a switching power converter to power LED strings using a predictive feedforward control mechanism. An LED controller determines programmed current levels and duty cycles for driving LED strings. The LED controller determines a predicted load for a subsequent cycle of a switching power converter driving the LED strings based on the programmed current levels and duty cycles. A power conversion controller uses the predicted load information to control switching of the switching power converter. This improves the dynamic response of the switching converter to changing load conditions, thereby improving overall power efficiency and performance of the system.
    Type: Application
    Filed: December 28, 2011
    Publication date: July 4, 2013
    Applicant: IWATT INC,
    Inventors: John William Kesterson, Xiaoyan Wang, Xuecheng Jin, Enzhu Liang, Selcuk Sen
  • Publication number: 20130147374
    Abstract: An LED driver controls current through an LED string. The LED driver generates a boosted PWM signal to drive a PWM transistor in the LED current path such that the PWM transistor maintains a substantially constant VGS, thus minimizing turn-on impedance of the PWM transistor. A current mirror circuit controls peak LED current when the PWM transistor is on. A trimming circuit includes a set of programmable switches to couple or decouple trimming transistor from the LED current path, and allowing for fine calibration of the LED current. By maintaining a low resistance and compensating for current mismatch in the LED current path, the LED driver provides efficient power performance and robustness that is particularly beneficial in high current applications.
    Type: Application
    Filed: December 7, 2011
    Publication date: June 13, 2013
    Applicant: IWATT INC.
    Inventors: Minjong Kim, Enzhu Liang, Xuecheng Jin
  • Publication number: 20120223648
    Abstract: A system that provides an intelligent approach to driving multiple strings of LEDs. A processing device determines an optimal current level for each LED string from a limited set of allowed currents. The processing device also determines a PWM duty cycle for driving the LEDs in each LED string to provide precise brightness control over the LED string. The settings for the current level and duty cycle are transmitted to an LED driver for regulating the current and on-off times of the LED strings. Beneficially, the system reduces the size of the LED driver while leveraging existing resources available in the processing device to operate the LEDs in a power efficient manner.
    Type: Application
    Filed: March 3, 2011
    Publication date: September 6, 2012
    Applicant: IWATT INC.
    Inventors: Xuecheng Jin, Minjong Kim, Enzhu Liang, John William Kesterson, Xiaoyan Wang
  • Publication number: 20110096572
    Abstract: A start-up circuit in a switch-mode power converter that employs a Zener diode to provide a reference voltage to reduce the power consumption and the size of the start-up circuit. The start-up circuit also includes a coarse current source and a coarse reference voltage signal generator for producing current and reference voltage for initial startup operation of a bandgap circuit. The reference signal and current from coarse current source and the reference voltage signal generator are subject to large process, voltage and temperature (PVT) variations or susceptible to noise from the power supply, and hence, these signals are used temporarily during start-up and replaced with signals from higher performance components. After bandgap circuit becomes operational, the start-up receives voltage reference signal from the bandgap circuit to more accurately detect undervoltage lockout conditions.
    Type: Application
    Filed: October 19, 2010
    Publication date: April 28, 2011
    Applicant: IWATT INC.
    Inventors: Enzhu Liang, Jiang Chen, Xuecheng Jin
  • Patent number: 7382308
    Abstract: A reference buffer includes a first current mirror, a second current mirror, a first source follower coupled in series to a branch of the first current mirror and receiving a first initial reference voltage and outputting a first reference voltage, a second source follower coupled in series to a branch of the second current mirror and receiving a second initial reference voltage and outputting a second reference voltage, and a resistor coupled between a first node and a second node outputting the first and second reference voltages, respectively. The first node is disposed between the first current mirror and the first source follower and the second node is disposed between the second current mirror and the second source follower. The voltage difference between the first reference voltage and the first initial reference voltage is substantially same as that between the second reference voltage and the second initial reference voltage.
    Type: Grant
    Filed: February 16, 2007
    Date of Patent: June 3, 2008
    Assignee: iWatt Inc.
    Inventors: Enzhu Liang, Xuecheng Jin