Patents by Inventor Man Ho Ku
Man Ho Ku 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: 9125270Abstract: A LED dimming device, and a LED dimming and a driving circuit using such LED dimming device are discussed. In present embodiment, the LED dimming device multiplexes an inputting switch and/or a sampling module of the LED driving circuit for dimming. such LED dimming device will not affect the sine waves of input current, in such a way, power factor and work efficiency will be increased while the harmonic coefficient and interference signal will be reduced.Type: GrantFiled: June 20, 2012Date of Patent: September 1, 2015Assignee: FREMONT MICRO DEVICES (SZ) LIMITEDInventors: Weiming Liao, Matthew Man Ho Ku, Yue Zheng, Lifang Guo, Guangyao You
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Patent number: 8599581Abstract: A switching mode power supply, and a primary-side controlled PFM converter using the primary-side regulated PFM controller are discussed. In present embodiment, the primary side cycle by cycle switch peak current is no longer a constant. The time detector is added to monitor the waveform of primary-side sample voltage and then generate the duty cycle. The transfer function should be selected to satisfy a specific relationship of switching frequency and switch peak current against with output loading current. The new design shows higher switching frequency but lower value of switch peak current at light load condition. This resolves the audible noise and poor transient response issue from the prior art PFM controller.Type: GrantFiled: February 16, 2012Date of Patent: December 3, 2013Assignee: Fremont Micro Devices (SZ) LimitedInventors: Yuquan Huang, Matthew Man Ho Ku
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Publication number: 20130241424Abstract: A LED dimming device, and a LED dimming and a driving circuit using such LED dimming device are discussed. In present embodiment, the LED dimming device multiplexes an inputting switch and/or a sampling module of the LED driving circuit for dimming. such LED dimming device will not affect the sine waves of input current, in such a way, power factor and work efficiency will be increased while the harmonic coefficient and interference signal will be reduced.Type: ApplicationFiled: June 20, 2012Publication date: September 19, 2013Applicant: FREMONT MICRO DEVICES (SZ) LIMITEDInventors: Weiming Liao, Matthew Man Ho Ku, Yue Zheng, Lifang Guo, Guangyao You
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Publication number: 20130215649Abstract: A switching mode power supply, and a primary-side controlled PFM converter using the primary-side regulated PFM controller are discussed. In present embodiment, the primary side cycle by cycle switch peak current is no longer a constant. The time detector is added to monitor the waveform of primary-side sample voltage and then generate the duty cycle. The transfer function should be selected to satisfy a specific relationship of switching frequency and switch peak current against with output loading current. The new design shows higher switching frequency but lower value of switch peak current at light load condition. This resolves the audible noise and poor transient response issue from the prior art PFM controller.Type: ApplicationFiled: February 16, 2012Publication date: August 22, 2013Inventors: Yuquan HUANG, Matthew Man Ho Ku
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Patent number: 8427114Abstract: The present invention relates to a charge status indicator and a charger. The charger comprises a charging power supply and a charge status indicator, wherein, the charge status indicator comprises a detecting chip for monitoring charge status connected between the primary winding of transformer and ground, and a display module used for displaying the charge status, wherein, said detecting chip for monitoring charge status comprising: a detecting module for detecting the charging state of the charge power supply; a comparing module for determining the current charge status based on the detected charging state. By employing the charger or the charge status indicator for a charger, a primary-side feedback control Flyback SMPS may be employed, just a simple and reliable circuit is needed, and higher efficient can be achieved.Type: GrantFiled: June 23, 2009Date of Patent: April 23, 2013Assignee: Evergreen Micro Devices Co., Ltd.Inventors: Weiming Liao, Matthew Man Ho Ku, Yue Zheng
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Patent number: 8201012Abstract: The present invention relates to a frequency jittering device and method, and a switching power supply employing such frequency jittering device. Said method comprises: S1 generating a variable logic number; S2 generating a delay signal; S3 generating a PWM control signal according to the variable logic number and the delay signal; S4 generating an output signal according to the PWM control signal; and S5 generating a clock signal with variable frequency according to the output signal; wherein, the clock signal is fed back to update the variable logic number, and a jittering clock signal modified in each clock cycle is produced. The benefit of the present invention is not only can apply small low cost EMI filter but also can keep the noise floor level low enough at light load condition.Type: GrantFiled: April 24, 2009Date of Patent: June 12, 2012Assignee: Evergreen Micro Devices Co., Ltd.Inventor: Matthew Man Ho Ku
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Patent number: 8129958Abstract: A controller for reducing the harmonics contents in the AC-to-DC converter that is capable of minimizing THD due to crossover distortion. The controller can approximate the shape of the current running through boost inductor to the sinusoidal waveform of the rectified line input voltage and in the meantime to keep the valley of rectified sinusoidal waveform line voltage close to local ground value. The controller can be used in a transition mode power factor correction device suitable for a wide range of AC line input voltage and output loading application.Type: GrantFiled: March 25, 2009Date of Patent: March 6, 2012Assignee: Evergreen Micro Devices Co., Ltd.Inventors: Matthew Man Ho Ku, Run Qin Tan
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Patent number: 8045308Abstract: The present invention relates to clamp protection circuit and a PFC control circuit employing such clamp protection circuit. Said clamp protection circuit comprises a high voltage isolation module used for receiving power from a high voltage power supply; a voltage clamp module used for receiving an output low voltage from the high voltage isolation module and realizing a clamp protection; and a low voltage bias module used for providing bias voltage to the high voltage isolation module and the voltage clamp module. By employing the clamp protection circuit, the precision of the clamp voltage is improved, the design is simplified and the silicon area is reduced. Meanwhile, the transient response is enhanced.Type: GrantFiled: April 2, 2009Date of Patent: October 25, 2011Assignee: Evergreen Micro Devices Co., Ltd.Inventors: Run Qin Tan, Li Fang Guo, Matthew Man Ho Ku
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Publication number: 20100321193Abstract: The present invention relates to a charge status indicator and a charger. The charger comprises a charging power supply and a charge status indicator, wherein, the charge status indicator comprises a detecting chip for monitoring charge status connected between the primary winding of transformer and ground, and a display module used for displaying the charge status, wherein, said detecting chip for monitoring charge status comprising: a detecting module for detecting the charging state of the charge power supply; a comparing module for determining the current charge status based on the detected charging state. By employing the charger or the charge status indicator for a charger, a primary-side feedback control Flyback SMPS may be employed, just a simple and reliable circuit is needed, and higher efficient can be achieved.Type: ApplicationFiled: June 23, 2009Publication date: December 23, 2010Applicant: EVERGREEN MICRO DEVICES CO., LTD.Inventors: Weiming Liao, Matthew Man Ho Ku, Yue Zheng
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Publication number: 20100275052Abstract: The present invention relates to a frequency jittering device and method, and a switching power supply employing such frequency jittering device. Said method comprises: S1 generating a variable logic number; S2 generating a delay signal; S3 generating a PWM control signal according to the variable logic number and the delay signal; S4 generating an output signal according to the PWM control signal; and S5 generating a clock signal with variable frequency according to the output signal; wherein, the clock signal is fed back to update the variable logic number, and a jittering clock signal modified in each clock cycle is produced. The benefit of the present invention is not only can apply small low cost EMI filter but also can keep the noise floor level low enough at light load condition.Type: ApplicationFiled: April 24, 2009Publication date: October 28, 2010Applicant: EVERGREEN MICRO DEVICES CO., LTD.Inventor: Matthew Man Ho Ku
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Publication number: 20100253410Abstract: The present invention relates to clamp protection circuit and a PFC control circuit employing such clamp protection circuit. Said clamp protection circuit comprises a high voltage isolation module used for receiving power from a high voltage power supply; a voltage clamp module used for receiving an output low voltage from the high voltage isolation module and realizing a clamp protection; and a low voltage bias module used for providing bias voltage to the high voltage isolation module and the voltage clamp module. By employing the clamp protection circuit, the precision of the clamp voltage is improved, the design is simplified and the silicon area is reduced. Meanwhile, the transient response is enhanced.Type: ApplicationFiled: April 2, 2009Publication date: October 7, 2010Applicant: EVERGREEN MICRO DEVICES CO., LTD.Inventors: Run Qin Tan, Li Fang Guo, Matthew Man Ho Ku
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Publication number: 20100246226Abstract: The present invention relates to controller for reducing the harmonics contents in the AC-to-DC converter.Type: ApplicationFiled: March 25, 2009Publication date: September 30, 2010Applicant: EVERGREEN MICRO DEVICES CO., LTD.Inventors: Matthew Man Ho Ku, Run Qin Tan
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Patent number: 6442195Abstract: An analog front end (AFE) circuit used in a high-speed communications system is presented that includes multiple stages each including a bandpass filter, base band modulator, low pass filter and Sigma-Delta modulator. Each stage processes a fractional portion of the total frequency of a wide bandwidth analog signal. The number of such AFE stages is configurable in parallel to process the entire bandwidth of the received signal. The AFEs can be incorporated in a single integrated circuit or similar suitable manner so as to be modular, and easily replaceable/upgradeable. To achieve minimum quantization noise and reduce manufacturing costs, the Sigma-Delta modulators in each AFE are made to have identical characteristics. Because the wideband signal is broken down into smaller frequency portions, the sampling rate, and thus the complexity and cost associated with the AFEs, is reduced significantly.Type: GrantFiled: August 27, 1997Date of Patent: August 27, 2002Assignee: Integrated Telecom Express, Inc.Inventors: Ming-Kang Liu, Man Ho Ku, Yukuang Wang
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Patent number: 6424925Abstract: A tone detector includes at least one circuit (hereinafter “single phase reference matcher”) that not only performs a convolution of an input signal with a reference signal, but also compares the result of convolution with a threshold to determine if there is a match, and if so drives a signal active indicating that tone is present. If there is no match, another circuit (hereinafter “phase shifter”) delays the reference signal by a fraction (e.g. ⅛) of the measuring period, thereby to introduce a phase shift (e.g. &pgr;/8) between the input signal and the reference signal. The “single phase reference matcher” again performs the just-described operation, this time with a delayed reference signal, and repeats the operation as often as necessary (e.g. eight times) to cycle through the entire measuring period, thereby to ensure that tone (if present in the input signal) is detected irrespective of phase, during one of the operations.Type: GrantFiled: August 31, 1999Date of Patent: July 23, 2002Assignee: Integrated Telecom Express, Inc.Inventors: Man Ho Ku, Wai-Hung Leung, Po-Sheng Chou, Ying-chang Chen