Patents by Inventor Cheng-Sung Chen
Cheng-Sung Chen 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: 10992234Abstract: A circuit for controlling a power converter includes an SR switching device, a light load detection circuit generating a load detection signal in response to a conduction signal and an operation mode signal, and an SR driver generating a control signal having a value according to the load detection signal and provide the control signal to the SR switching device. A method of controlling a power converter includes generating a load detection signal in response to a conduction signal and an operation mode signal and generating a control signal having a value according to the load detection signal. The control signal has a first value when the load detection signal is asserted and has a second value when the load detection signal is de-asserted.Type: GrantFiled: January 23, 2018Date of Patent: April 27, 2021Assignee: SEMICONDUCTOR COMPONENTS INDUSTRIES, LLCInventors: Sangcheol Moon, Jintae Kim, Chi-Chen Chung, Cheng-Sung Chen
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Patent number: 10608544Abstract: A Synchronous Rectifier (SR) controller circuit includes a dead time evaluation circuit, an offset voltage controller circuit, an off threshold control circuit, and a comparator circuit. The dead time evaluation circuit produces an indication of whether a measured dead time of an SR switching device is less than a target dead time. The offset voltage controller circuit determines an offset count using the indication, an offset voltage using the offset count, and high and low saturation indicators according to the offset count. The off threshold control circuit determines a threshold count using the high and low saturation indicators and an off threshold voltage using the threshold count. The comparator circuit determines whether a measured voltage of the SR switching device is greater than a virtual off threshold voltage, the virtual off threshold voltage corresponding to the off threshold voltage minus the offset voltage.Type: GrantFiled: September 19, 2018Date of Patent: March 31, 2020Assignee: SEMICONDUCTOR COMPONENTS INDUSTRIES, LLCInventors: Sangcheol Moon, Hangseok Choi, Chi Chen Chung, Cheng-Sung Chen
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Publication number: 20190229634Abstract: A circuit for controlling a power converter includes an SR switching device, a light load detection circuit generating a load detection signal in response to a conduction signal and an operation mode signal, and an SR driver generating a control signal having a value according to the load detection signal and provide the control signal to the SR switching device. A method of controlling a power converter includes generating a load detection signal in response to a conduction signal and an operation mode signal and generating a control signal having a value according to the load detection signal. The control signal has a first value when the load detection signal is asserted and has a second value when the load detection signal is de-asserted.Type: ApplicationFiled: January 23, 2018Publication date: July 25, 2019Applicant: SEMICONDUCTOR COMPONENTS INDUSTRIES, LLCInventors: Sangcheol MOON, Jintae KIM, Chi-Chen CHUNG, Cheng-Sung CHEN
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Publication number: 20190020283Abstract: A Synchronous Rectifier (SR) controller circuit includes a dead time evaluation circuit, an offset voltage controller circuit, an off threshold control circuit, and a comparator circuit. The dead time evaluation circuit produces an indication of whether a measured dead time of an SR switching device is less than a target dead time. The offset voltage controller circuit determines an offset count using the indication, an offset voltage using the offset count, and high and low saturation indicators according to the offset count. The off threshold control circuit determines a threshold count using the high and low saturation indicators and an off threshold voltage using the threshold count. The comparator circuit determines whether a measured voltage of the SR switching device is greater than a virtual off threshold voltage, the virtual off threshold voltage corresponding to the off threshold voltage minus the offset voltage.Type: ApplicationFiled: September 19, 2018Publication date: January 17, 2019Applicant: SEMICONDUCTOR COMPONENTS INDUSTRIES, LLCInventors: Sangcheol MOON, Hangseok CHOI, Chi Chen CHUNG, Cheng-Sung CHEN
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Patent number: 10110137Abstract: A Synchronous Rectifier (SR) controller circuit includes a dead time evaluation circuit, an offset voltage controller circuit, an off threshold control circuit, and a comparator circuit. The dead time evaluation circuit produces an indication of whether a measured dead time of an SR switching device is less than a target dead time. The offset voltage controller circuit determines an offset count using the indication, an offset voltage using the offset count, and high and low saturation indicators according to the offset count. The off threshold control circuit determines a threshold count using the high and low saturation indicators and an off threshold voltage using the threshold count. The comparator circuit determines whether a measured voltage of the SR switching device is greater than a virtual off threshold voltage, the virtual off threshold voltage corresponding to the off threshold voltage minus the offset voltage.Type: GrantFiled: April 13, 2017Date of Patent: October 23, 2018Assignee: SEMICONDUCTOR COMPONENTS INDUSTRIES, LLCInventors: Sangcheol Moon, Hangseok Choi, Chi Chen Chung, Cheng-Sung Chen
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Publication number: 20180301999Abstract: A Synchronous Rectifier (SR) controller circuit includes a dead time evaluation circuit, an offset voltage controller circuit, an off threshold control circuit, and a comparator circuit. The dead time evaluation circuit produces an indication of whether a measured dead time of an SR switching device is less than a target dead time. The offset voltage controller circuit determines an offset count using the indication, an offset voltage using the offset count, and high and low saturation indicators according to the offset count. The off threshold control circuit determines a threshold count using the high and low saturation indicators and an off threshold voltage using the threshold count. The comparator circuit determines whether a measured voltage of the SR switching device is greater than a virtual off threshold voltage, the virtual off threshold voltage corresponding to the off threshold voltage minus the offset voltage.Type: ApplicationFiled: April 13, 2017Publication date: October 18, 2018Applicant: SEMICONDUCTOR COMPONENTS INDUSTRIES, LLCInventors: Sangcheol MOON, Hangseok CHOI, Chi Chen CHUNG, Cheng-Sung CHEN
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Patent number: 10027235Abstract: A flyback converter includes a primary-side switch that controls conduction of current on a primary side of a transformer and a synchronous rectifier on a secondary side of the transformer. A synchronous rectifier driver controls the conduction of the synchronous rectifier by adaptively adjusting a turn-off threshold of the synchronous rectifier.Type: GrantFiled: November 22, 2016Date of Patent: July 17, 2018Assignee: FAIRCHILD SEMICONDUCTOR CORPORATIONInventors: Hangseok Choi, Lei Chen, Cheng-Sung Chen
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Patent number: 10008950Abstract: A switching converter includes a synchronous rectifier and a synchronous rectifier driver that controls conduction of the synchronous rectifier. The synchronous rectifier driver turns OFF the synchronous rectifier in response to a turn-off trigger. The synchronous rectifier driver prevents the turn-off trigger from turning OFF the synchronous rectifier during a turn-off trigger blanking time that is adaptively set based on a conduction time of the synchronous rectifier.Type: GrantFiled: October 23, 2017Date of Patent: June 26, 2018Assignee: SEMICONDUCTOR COMPONENTS INDUSTRIES, LLCInventors: Hangseok Choi, Lei Chen, Cheng-Sung Chen
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Patent number: 9991810Abstract: A synchronous rectifier driver pre-positions a gate of a synchronous rectifier to allow for fast turn-off. The synchronous rectifier driver turns ON the synchronous rectifier by driving the gate at a high level for a period of time that is based on a previous conduction time of the synchronous rectifier. The synchronous rectifier driver thereafter drives the gate at a lower level that is sufficient to keep the synchronous rectifier ON. The synchronous rectifier can be quickly turned OFF by further reducing the level of the drive signal at the gate of the synchronous rectifier.Type: GrantFiled: November 22, 2016Date of Patent: June 5, 2018Assignee: FAIRCHILD SEMICONDUCTOR CORPORATIONInventors: Hangseok Choi, Wei-Hsuan Huang, Cheng-Sung Chen
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Publication number: 20180048241Abstract: A switching converter includes a synchronous rectifier and a synchronous rectifier driver that controls conduction of the synchronous rectifier. The synchronous rectifier driver turns OFF the synchronous rectifier in response to a turn-off trigger. The synchronous rectifier driver prevents the turn-off trigger from turning OFF the synchronous rectifier during a turn-off trigger blanking time that is adaptively set based on a conduction time of the synchronous rectifier.Type: ApplicationFiled: October 23, 2017Publication date: February 15, 2018Applicant: FAIRCHILD SEMICONDUCTOR CORPORATIONInventors: Hangseok CHOI, Lei CHEN, Cheng-Sung CHEN
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Patent number: 9825548Abstract: A switching converter includes a synchronous rectifier and a synchronous rectifier driver that controls conduction of the synchronous rectifier. The synchronous rectifier driver turns OFF the synchronous rectifier in response to a turn-off trigger. The synchronous rectifier driver prevents the turn-off trigger from turning OFF the synchronous rectifier during a turn-off trigger blanking time that is adaptively set based on a conduction time of the synchronous rectifier.Type: GrantFiled: November 22, 2016Date of Patent: November 21, 2017Assignee: Fairchild Semiconductor CorporationInventors: Hangseok Choi, Lei Chen, Cheng-Sung Chen
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Publication number: 20170244333Abstract: A synchronous rectifier driver pre-positions a gate of a synchronous rectifier to allow for fast turn-off. The synchronous rectifier driver turns ON the synchronous rectifier by driving the gate at a high level for a period of time that is based on a previous conduction time of the synchronous rectifier. The synchronous rectifier driver thereafter drives the gate at a lower level that is sufficient to keep the synchronous rectifier ON. The synchronous rectifier can be quickly turned OFF by further reducing the level of the drive signal at the gate of the synchronous rectifier.Type: ApplicationFiled: November 22, 2016Publication date: August 24, 2017Applicant: FAIRCHILD SEMICONDUCTOR CORPORATIONInventors: Hangseok CHOI, Wei-Hsuan HUANG, Cheng-Sung CHEN
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Publication number: 20170222568Abstract: A switching converter includes a synchronous rectifier and a synchronous rectifier driver that controls conduction of the synchronous rectifier. The synchronous rectifier driver turns OFF the synchronous rectifier in response to a turn-off trigger. The synchronous rectifier driver prevents the turn-off trigger from turning OFF the synchronous rectifier during a turn-off trigger blanking time that is adaptively set based on a conduction time of the synchronous rectifier.Type: ApplicationFiled: November 22, 2016Publication date: August 3, 2017Applicant: FAIRCHILD SEMICONDUCTOR CORPORATIONInventors: Hangseok CHOI, Lei CHEN, Cheng-Sung CHEN
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Publication number: 20170222569Abstract: A flyback converter includes a primary-side switch that controls conduction of current on a primary side of a transformer and a synchronous rectifier on a secondary side of the transformer. A synchronous rectifier driver controls the conduction of the synchronous rectifier by adaptively adjusting a turn-off threshold of the synchronous rectifier.Type: ApplicationFiled: November 22, 2016Publication date: August 3, 2017Applicant: FAIRCHILD SEMICONDUCTOR CORPORATIONInventors: Hangseok CHOI, Lei CHEN, Cheng-Sung CHEN
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Patent number: 9141118Abstract: A control circuit of a power converter is provided. The control circuit comprises a PWM circuit, a sample circuit, and emulation circuit. The PWM circuit generates a switching signal for switching an inductor and generating a switching current of the inductor in response to a current feedback signal. The sample circuit is coupled to sample a switching current signal into a capacitor during an on time of the switching signal. The emulation circuit generates a discharge current couple to discharge the capacitor during an off time of the switching signal for generating the current feedback signal. The switching current signal is correlated to the switching current of the inductor, and the discharge current is generated in response to an input voltage of the inductor, an output voltage of the power converter, and the on time of the switching signal.Type: GrantFiled: December 4, 2012Date of Patent: September 22, 2015Assignee: SYSTEM GENERAL CORPORATIONInventors: Ta-Yung Yang, Ying-Chi Chen, Chien-Tsun Hsu, Cheng-Sung Chen
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Patent number: 8564257Abstract: The present invention relates to a power factor correction circuit and a driving method thereof. The power factor correction circuit includes a power switch controlling an inductor current flowing in an inductor, an auxiliary inductor coupled to the inductor with a predetermined turn ratio, and a power factor correction controller controlling output power by controlling a switching operation of the power switch. The power factor correction controller determines whether or not an output voltage of the output power is an over-voltage by using the sum of a source current and a sink current that control a zero current detection voltage to be included within a predetermined clamping range, the zero current detection voltage corresponding to an auxiliary voltage that is a both-end voltage of an auxiliary inductor.Type: GrantFiled: October 26, 2010Date of Patent: October 22, 2013Assignee: Fairchild Korea Semiconductor Ltd.Inventors: Young-Bae Park, Sang Cheol Moon, Byoung Heon Kim, Byung Kwon Choi, Cheng Sung Chen
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Patent number: 8482268Abstract: The present invention provides a correction circuit for a power converter. The correction circuit includes a sampling circuit, a demagnetizing-time circuit, a duty circuit, and a compensation circuit. The sampling circuit generates an average-current signal in response to a switching current of the power converter. The demagnetizing-time circuit generates a discharging-time signal in response to a switching signal and an input-voltage signal. The duty circuit generates a duty signal in response to the discharging-time signal, an on-time of the switching signal, and a switching period of the switching signal. The compensation circuit is coupled to receive the average-current signal and the duty signal for generating a corrected signal. The switching signal is utilized to switch a magnetic device for regulating an output voltage of the power converter. The corrected signal is coupled to generate the switching signal.Type: GrantFiled: May 6, 2011Date of Patent: July 9, 2013Assignee: System General CorporationInventors: Ta-Yung Yang, Ying-Chi Chen, Cheng-Sung Chen, Meng-Hsun Yu
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Publication number: 20130141056Abstract: A control circuit of a power factor correction (PFC) converter is provided. The control circuit includes a pulse width modulation (PWM) circuit, an amplifier, a detection circuit., and a capacitor. The PWM circuit generates a switching signal in response to a loop signal. The amplifier is coupled to generate the loop signal in response to a switching current. The detection circuit generates a mode signal coupled to change output impedance of the amplifier. The capacitor is coupled to the amplifier for loop frequency compensation. The switching signal is coupled to switch an inductor of the PFC power converter and generate the switching current.Type: ApplicationFiled: July 27, 2012Publication date: June 6, 2013Applicant: SYSTEM GENERAL CORPORATIONInventors: Ta-Yung YANG, Ying-Chi CHEN, Chien-Tsun HSU, Cheng-Sung CHEN
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Patent number: 8373399Abstract: A control circuit of an interleaved PFC power converter according to the present invention comprises a master switching control circuit, a slave switching control circuit, and a slave reference signal generator. The master switching control circuit generates a control signal and a first switching signal in response to an input voltage and a feedback signal. The first switching signal is utilized to control a first switch of the PFC power converter. The slave reference signal generator generates a slave control signal in response to a load condition of the PFC power converter and the control signal. The slave switching control circuit generates a second switching signal in response to the slave control signal. The slave control signal is utilized to control a second switch of the PFC power converter. The slave reference signal generator adjusts the control signal in response to the load condition for generating the slave control signal correspondingly.Type: GrantFiled: October 29, 2010Date of Patent: February 12, 2013Assignee: System General Corp.Inventors: Ta-Yung Yang, Cheng-Sung Chen, Rui-Hong Lu
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Publication number: 20120069611Abstract: The present invention provides a correction circuit for a power converter. The correction circuit includes a sampling circuit, a demagnetizing-time circuit, a duty circuit, and a compensation circuit. The sampling circuit generates an average-current signal in response to a switching current of the power converter. The demagnetizing-time circuit generates a discharging-time signal in response to a switching signal and an input-voltage signal. The duty circuit generates a duty signal in response to the discharging-time signal, an on-time of the switching signal, and a switching period of the switching signal. The compensation circuit is coupled to receive the average-current signal and the duty signal for generating a corrected signal. The switching signal is utilized to switch a magnetic device for regulating an output voltage of the power converter. The corrected signal is coupled to generate the switching signal.Type: ApplicationFiled: May 6, 2011Publication date: March 22, 2012Applicant: SYSTEM GENERAL CORPORATIONInventors: Ta-Yung Yang, Ying-Chi Chen, Cheng-Sung Chen, Meng-Hsun Yu