Patents by Inventor Xuecheng Jin
Xuecheng Jin 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).
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Patent number: 9564085Abstract: Selective dimming in a light emitting display device to reduce power consumption. The display device includes a display panel that includes a plurality of light emitting pixels. An image processor is configured to divide an image frame into a plurality of regions and to reduce pixel intensity levels in at least one region of the plurality of regions to generate an adjusted image frame. The at least one region corresponds to a background of the image frame. A display driver converts data for the adjusted image frame into control signals for controlling brightness of the light emitting pixels. The display device may be, for example, an organic light emitting diode (OLED) display device or other type of display device that includes light emitting pixels.Type: GrantFiled: May 9, 2013Date of Patent: February 7, 2017Assignee: Dialog Semiconductor Inc.Inventors: Xuecheng Jin, Gyan Tiwary
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Patent number: 9451664Abstract: An adaptive switch mode LED driver provides an intelligent approach to driving multiple strings of LEDs. The LED driver determines an optimal current level for each LED channel from a limited set of allowed currents. The LDO driver then determines a PWM duty cycle for driving the LEDs in each LED channel to provide precise brightness control over the LED channels. Beneficially, the LED driver minimizes the power dissipation in the LDO circuits driving each LED string, while also ensuring that the currents in each LED string are maintained within a limited range. A sample and hold LDO allows PWM control over extreme duty cycles with very fast dynamic response. Furthermore, fault protection circuitry ensures fault-free startup and operation of the LED driver.Type: GrantFiled: November 13, 2012Date of Patent: September 20, 2016Assignee: Dialog Semiconductor Inc.Inventors: Xuecheng Jin, Yu Cheng Chang, Yang Li, Maofeng Lan, John W. Kesterson, Xiaoyan Wang, Chenghung Pan
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Patent number: 9239816Abstract: A method of power system preventive control candidate measures identification self-adaptive to external environment, which is applicable to dynamic identification of stations and power equipment under the effect of calamity, and judgment of preventive control measures that lose or restore control capability, and those for which control range or cost has changed. Automatic online identification of set of preventive control candidate measures includes two tasks: identification of stations and power equipment under the effect of calamity, and adjustment of the space of preventive control measures.Type: GrantFiled: October 17, 2011Date of Patent: January 19, 2016Assignees: JIANGXI ELECTRIC POWER COMPANY, STATE GRID ELECTRIC POWER RESEARCH INSTITUTEInventors: Xuecheng Jin, Haohao Wang, Zhuxiang Yao, Taishan Xu, Genhua Zou, Bijun Li, Jianhua Xiong, Wei Xu, Feng Wen, Huimin Peng
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Patent number: 9224340Abstract: A Predictive Power Control (PPC) device within a TCON Bias IC that addresses an overdesign inefficiency and enables a low cost solution. A PPC block utilizes the next frame image data and interacts with a pulse width modulation (PWM) control block of internal regulators to proactively prepare the output voltages of a power regulator for the power requirements in one or more future frames, for example.Type: GrantFiled: May 23, 2012Date of Patent: December 29, 2015Assignee: Dialog Semiconductor Inc.Inventor: Xuecheng Jin
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Patent number: 9161402Abstract: 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: GrantFiled: March 31, 2014Date of Patent: October 13, 2015Assignee: Dialog Semiconductor Inc.Inventors: Minjong Kim, Enzhu Liang, Xuecheng Jin
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Publication number: 20140210365Abstract: 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: ApplicationFiled: March 31, 2014Publication date: July 31, 2014Applicant: Dialog Semiconductor Inc.Inventors: Minjong Kim, Enzhu Liang, Xuecheng Jin
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Patent number: 8791647Abstract: 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: GrantFiled: December 28, 2011Date of Patent: July 29, 2014Assignee: Dialog Semiconductor Inc.Inventors: John William Kesterson, Xiaoyan Wang, Xuecheng Jin, Enzhu Liang, Selcuk Sen
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Patent number: 8710753Abstract: 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: GrantFiled: December 7, 2011Date of Patent: April 29, 2014Assignee: Dialog Semiconductor Inc.Inventors: Minjong Kim, Enzhu Liang, Xuecheng Jin
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Patent number: 8710752Abstract: 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: GrantFiled: March 3, 2011Date of Patent: April 29, 2014Assignee: Dialog Semiconductor Inc.Inventors: Xuecheng Jin, Minjong Kim, Enzhu Liang, John William Kesterson, Xiaoyan Wang
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Publication number: 20140009510Abstract: A light emitting display device with backlight dimming compensation. A backlight emits light based on a backlight control signal. A power supply generates a first supply voltage based on a supply control signal. A data driver converts pixel data into analog data voltages. A dynamic voltage range of the analog data voltages is controlled by the first supply voltage. A pixel array includes a plurality of pixels, and transparency of the pixels to the light emitted by the backlight is based on the analog data voltages. A power control module of the display device determines if a power condition is met and, responsive to the power condition being met, adjusts the backlight control signal to reduce a brightness of light emitted by the backlight and adjusts the supply control signal to increase the first supply voltage.Type: ApplicationFiled: June 18, 2013Publication date: January 9, 2014Inventor: Xuecheng Jin
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Publication number: 20130314391Abstract: A Predictive Power Control (PPC) device within a TCON Bias IC that addresses an overdesign inefficiency and enables a low cost solution. A PPC block utilizes the next frame image data and interacts with a pulse width modulation (PWM) control block of internal regulators to proactively prepare the output voltages of a power regulator for the power requirements in one or more future frames, for example.Type: ApplicationFiled: May 23, 2012Publication date: November 28, 2013Applicant: IWATT INC.Inventor: Xuecheng Jin
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Publication number: 20130314454Abstract: Selective dimming in a light emitting display device to reduce power consumption. The display device includes a display panel that includes a plurality of light emitting pixels. An image processor is configured to divide an image frame into a plurality of regions and to reduce pixel intensity levels in at least one region of the plurality of regions to generate an adjusted image frame. The at least one region corresponds to a background of the image frame. A display driver converts data for the adjusted image frame into control signals for controlling brightness of the light emitting pixels. The display device may be, for example, an organic light emitting diode (OLED) display device or other type of display device that includes light emitting pixels.Type: ApplicationFiled: May 9, 2013Publication date: November 28, 2013Applicant: iWatt Inc.Inventors: Xuecheng Jin, Gyan Tiwary
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Patent number: 8581568Abstract: 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: GrantFiled: October 19, 2010Date of Patent: November 12, 2013Assignee: iWatt Inc.Inventors: Enzhu Liang, Jiang Chen, Xuecheng Jin
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Publication number: 20130246000Abstract: A method of power system preventive control candidate measures identification self-adaptive to external environment, which is applicable to dynamic identification of stations and power equipment under the effect of calamity, and judgment of preventive control measures that lose or restore control capability, and those for which control range or cost has changed. Automatic online identification of set of preventive control candidate measures includes two tasks: identification of stations and power equipment under the effect of calamity, and adjustment of the space of preventive control measures.Type: ApplicationFiled: October 17, 2011Publication date: September 19, 2013Applicants: State Grid Electric Power Research Institute, Jiangxi Electric Power CompanyInventors: Xuecheng Jin, Haohao Wang, Zhuxiang Yao, Taishan Xu, Genhua Zou, Bijun Li, Jianhua Xiong, Wei Xu, Feng Wen, Huimin Peng
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Publication number: 20130169172Abstract: 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: ApplicationFiled: December 28, 2011Publication date: July 4, 2013Applicant: IWATT INC,Inventors: John William Kesterson, Xiaoyan Wang, Xuecheng Jin, Enzhu Liang, Selcuk Sen
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Publication number: 20130147374Abstract: 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: ApplicationFiled: December 7, 2011Publication date: June 13, 2013Applicant: IWATT INC.Inventors: Minjong Kim, Enzhu Liang, Xuecheng Jin
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Publication number: 20130127344Abstract: An adaptive switch mode LED driver provides an intelligent approach to driving multiple strings of LEDs. The LED driver determines an optimal current level for each LED channel from a limited set of allowed currents. The LDO driver then determines a PWM duty cycle for driving the LEDs in each LED channel to provide precise brightness control over the LED channels. Beneficially, the LED driver minimizes the power dissipation in the LDO circuits driving each LED string, while also ensuring that the currents in each LED string are maintained within a limited range. A sample and hold LDO allows PWM control over extreme duty cycles with very fast dynamic response. Furthermore, fault protection circuitry ensures fault-free startup and operation of the LED driver.Type: ApplicationFiled: November 13, 2012Publication date: May 23, 2013Inventors: Xuecheng Jin, Yu Chong Chang, Yang Li, Maofeng Lan, John W. Kesterson, Xiaoyan Wang, Chenghung Pan
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Patent number: 8334662Abstract: An adaptive switch mode LED driver provides an intelligent approach to driving multiple strings of LEDs. The LED driver determines an optimal current level for each LED channel from a limited set of allowed currents. The LDO driver then determines a PWM duty cycle for driving the LEDs in each LED channel to provide precise brightness control over the LED channels. Beneficially, the LED driver minimizes the power dissipation in the LDO circuits driving each LED string, while also ensuring that the currents in each LED string are maintained within a limited range. A sample and hold LDO allows PWM control over extreme duty cycles with very fast dynamic response. Furthermore, fault protection circuitry ensures fault-free startup and operation of the LED driver.Type: GrantFiled: September 11, 2009Date of Patent: December 18, 2012Assignee: iWatt Inc.Inventors: Xuecheng Jin, Yu Cheng Chang, Yang Li, Maofeng Lan, John W. Kesterson, Xiaoyan Wang, Chenghung Pan
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Publication number: 20120223648Abstract: 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: ApplicationFiled: March 3, 2011Publication date: September 6, 2012Applicant: IWATT INC.Inventors: Xuecheng Jin, Minjong Kim, Enzhu Liang, John William Kesterson, Xiaoyan Wang
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Patent number: 8184762Abstract: A digital phase lock loop circuit provides an output with reduced jitter. The digital phase lock loop circuit includes a phase frequency detector that determines a phase difference between a feedback signal and a reference frequency signal to generate an error signal indicative of the phase difference. A numerically controlled oscillator generates a first oscillator output signal with a frequency proportional to the error signal and a second oscillator output signal indicative of jitter of the first oscillator output signal in reference to the reference frequency signal. A phase accuracy extender determines a delay amount from the second oscillator output signal and delays the first oscillator output signal by the delay amount to generate a phase-enhanced output signal with edges aligned with one of a plurality of reference clock signals.Type: GrantFiled: November 6, 2008Date of Patent: May 22, 2012Assignee: iWatt, Inc.Inventors: John W. Kesterson, Carrie Seim, Selcuk Sen, Xuecheng Jin