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).

  • Publication number: 20190020283
    Abstract: 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: Application
    Filed: September 19, 2018
    Publication date: January 17, 2019
    Applicant: SEMICONDUCTOR COMPONENTS INDUSTRIES, LLC
    Inventors: Sangcheol MOON, Hangseok CHOI, Chi Chen CHUNG, Cheng-Sung CHEN
  • Patent number: 10110137
    Abstract: 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: Grant
    Filed: April 13, 2017
    Date of Patent: October 23, 2018
    Assignee: SEMICONDUCTOR COMPONENTS INDUSTRIES, LLC
    Inventors: Sangcheol Moon, Hangseok Choi, Chi Chen Chung, Cheng-Sung Chen
  • Publication number: 20180301999
    Abstract: 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: Application
    Filed: April 13, 2017
    Publication date: October 18, 2018
    Applicant: SEMICONDUCTOR COMPONENTS INDUSTRIES, LLC
    Inventors: Sangcheol MOON, Hangseok CHOI, Chi Chen CHUNG, Cheng-Sung CHEN
  • Patent number: 10027235
    Abstract: 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: Grant
    Filed: November 22, 2016
    Date of Patent: July 17, 2018
    Assignee: FAIRCHILD SEMICONDUCTOR CORPORATION
    Inventors: Hangseok Choi, Lei Chen, Cheng-Sung Chen
  • Patent number: 10008950
    Abstract: 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: Grant
    Filed: October 23, 2017
    Date of Patent: June 26, 2018
    Assignee: SEMICONDUCTOR COMPONENTS INDUSTRIES, LLC
    Inventors: Hangseok Choi, Lei Chen, Cheng-Sung Chen
  • Patent number: 9991810
    Abstract: 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: Grant
    Filed: November 22, 2016
    Date of Patent: June 5, 2018
    Assignee: FAIRCHILD SEMICONDUCTOR CORPORATION
    Inventors: Hangseok Choi, Wei-Hsuan Huang, Cheng-Sung Chen
  • Publication number: 20180048241
    Abstract: 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: Application
    Filed: October 23, 2017
    Publication date: February 15, 2018
    Applicant: FAIRCHILD SEMICONDUCTOR CORPORATION
    Inventors: Hangseok CHOI, Lei CHEN, Cheng-Sung CHEN
  • Patent number: 9825548
    Abstract: 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: Grant
    Filed: November 22, 2016
    Date of Patent: November 21, 2017
    Assignee: Fairchild Semiconductor Corporation
    Inventors: Hangseok Choi, Lei Chen, Cheng-Sung Chen
  • Publication number: 20170244333
    Abstract: 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: Application
    Filed: November 22, 2016
    Publication date: August 24, 2017
    Applicant: FAIRCHILD SEMICONDUCTOR CORPORATION
    Inventors: Hangseok CHOI, Wei-Hsuan HUANG, Cheng-Sung CHEN
  • Publication number: 20170222568
    Abstract: 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: Application
    Filed: November 22, 2016
    Publication date: August 3, 2017
    Applicant: FAIRCHILD SEMICONDUCTOR CORPORATION
    Inventors: Hangseok CHOI, Lei CHEN, Cheng-Sung CHEN
  • Publication number: 20170222569
    Abstract: 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: Application
    Filed: November 22, 2016
    Publication date: August 3, 2017
    Applicant: FAIRCHILD SEMICONDUCTOR CORPORATION
    Inventors: Hangseok CHOI, Lei CHEN, Cheng-Sung CHEN
  • Patent number: 9141118
    Abstract: 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: Grant
    Filed: December 4, 2012
    Date of Patent: September 22, 2015
    Assignee: SYSTEM GENERAL CORPORATION
    Inventors: Ta-Yung Yang, Ying-Chi Chen, Chien-Tsun Hsu, Cheng-Sung Chen
  • Patent number: 8564257
    Abstract: 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: Grant
    Filed: October 26, 2010
    Date of Patent: October 22, 2013
    Assignee: Fairchild Korea Semiconductor Ltd.
    Inventors: Young-Bae Park, Sang Cheol Moon, Byoung Heon Kim, Byung Kwon Choi, Cheng Sung Chen
  • Patent number: 8482268
    Abstract: 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: Grant
    Filed: May 6, 2011
    Date of Patent: July 9, 2013
    Assignee: System General Corporation
    Inventors: Ta-Yung Yang, Ying-Chi Chen, Cheng-Sung Chen, Meng-Hsun Yu
  • Publication number: 20130141056
    Abstract: 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: Application
    Filed: July 27, 2012
    Publication date: June 6, 2013
    Applicant: SYSTEM GENERAL CORPORATION
    Inventors: Ta-Yung YANG, Ying-Chi CHEN, Chien-Tsun HSU, Cheng-Sung CHEN
  • Patent number: 8373399
    Abstract: 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: Grant
    Filed: October 29, 2010
    Date of Patent: February 12, 2013
    Assignee: System General Corp.
    Inventors: Ta-Yung Yang, Cheng-Sung Chen, Rui-Hong Lu
  • Publication number: 20120069611
    Abstract: 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: Application
    Filed: May 6, 2011
    Publication date: March 22, 2012
    Applicant: SYSTEM GENERAL CORPORATION
    Inventors: Ta-Yung Yang, Ying-Chi Chen, Cheng-Sung Chen, Meng-Hsun Yu
  • Publication number: 20120001600
    Abstract: 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: Application
    Filed: October 29, 2010
    Publication date: January 5, 2012
    Applicant: SYSTEM GENERAL CORP.
    Inventors: TA-YUNG YANG, CHENG-SUNG CHEN, RUI-HONG LU
  • Patent number: 8085021
    Abstract: A switching controller for a PFC converter is provided. The switching controller comprises a switching-control circuit, a current-command circuit, a programmable feedback circuit, a modulator, an over-voltage detection circuit, and a light-load detection circuit. The switching controller is capable of regulating a bulk voltage of the PFC converter at different levels in response to load conditions of the PFC converter. A turbo current eliminates a first voltage undershooting of the bulk voltage at the transient that the bulk voltage decreases to arrive at a second level from a first level. A voltage-loop error signal is maximized to eliminate a second voltage undershooting of the bulk voltage at the transient that the bulk voltage starts to increase toward the first level from the second level.
    Type: Grant
    Filed: April 7, 2009
    Date of Patent: December 27, 2011
    Assignee: System General Corp.
    Inventors: Cheng-Sung Chen, Chien-Tsun Hsu, Ting-Ta Chiang, Shao-Chun Huang
  • Patent number: 7999527
    Abstract: A switching controller for a boost power converter includes a switching-control circuit and a programmable feedback circuit. The programmable feedback circuit is coupled to an output of the boost power converter via a voltage divider. The programmable feedback circuit includes a current source coupled to a switch. On a light-load condition, a power-saving signal turns on the switch. The switch will conduct a programming current supplied by the current source toward the voltage divider. Furthermore, the voltage divider is externally adjustable for programming a determined level of an output voltage of the boost power converter on the light-load condition. Additionally the present invention increases system design flexibility to meet practical power-saving requirements without adding circuitries and increasing cost.
    Type: Grant
    Filed: October 30, 2008
    Date of Patent: August 16, 2011
    Assignee: System General Corp.
    Inventors: Ta-Yung Yang, Chien-Tsun Hsu, Cheng-Sung Chen, Ting-Ta Chiang