US20200169178A1 - Synchronous rectification device and method thereof - Google Patents

Synchronous rectification device and method thereof Download PDF

Info

Publication number
US20200169178A1
US20200169178A1 US16/258,124 US201916258124A US2020169178A1 US 20200169178 A1 US20200169178 A1 US 20200169178A1 US 201916258124 A US201916258124 A US 201916258124A US 2020169178 A1 US2020169178 A1 US 2020169178A1
Authority
US
United States
Prior art keywords
signal
level
control
side switch
secondary side
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
US16/258,124
Other versions
US10666155B1 (en
Inventor
Tso-Jen Peng
Ssu-Hao Wang
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Chicony Power Technology Co Ltd
Original Assignee
Chicony Power Technology Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Chicony Power Technology Co Ltd filed Critical Chicony Power Technology Co Ltd
Assigned to CHICONY POWER TECHNOLOGY CO., LTD. reassignment CHICONY POWER TECHNOLOGY CO., LTD. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: PENG, TSO-JEN, WANG, SSU-HAO
Application granted granted Critical
Publication of US10666155B1 publication Critical patent/US10666155B1/en
Publication of US20200169178A1 publication Critical patent/US20200169178A1/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M3/00—Conversion of dc power input into dc power output
    • H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
    • H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
    • H02M3/28—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
    • H02M3/325—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal
    • H02M3/335—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only
    • H02M3/33569—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only having several active switching elements
    • H02M3/33576—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only having several active switching elements having at least one active switching element at the secondary side of an isolation transformer
    • H02M3/33592—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only having several active switching elements having at least one active switching element at the secondary side of an isolation transformer having a synchronous rectifier circuit or a synchronous freewheeling circuit at the secondary side of an isolation transformer
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M1/00—Details of apparatus for conversion
    • H02M1/08—Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M1/00—Details of apparatus for conversion
    • H02M1/38—Means for preventing simultaneous conduction of switches
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M3/00—Conversion of dc power input into dc power output
    • H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
    • H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
    • H02M3/28—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
    • H02M3/325—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal
    • H02M3/335—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only
    • H02M3/33507—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of the output voltage or current, e.g. flyback converters
    • H02M3/33523—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of the output voltage or current, e.g. flyback converters with galvanic isolation between input and output of both the power stage and the feedback loop
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M3/00—Conversion of dc power input into dc power output
    • H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
    • H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
    • H02M3/28—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
    • H02M3/325—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal
    • H02M3/335—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only
    • H02M3/33569—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only having several active switching elements
    • H02M3/33576—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only having several active switching elements having at least one active switching element at the secondary side of an isolation transformer
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
    • Y02B70/10—Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Definitions

  • the present disclosure relates to the field of power conversion, and in particular, to a synchronous rectification device and a method thereof.
  • the power conversion technology belongs to a relatively important part in the electronics industry.
  • the synchronous rectification device includes a primary side switch and a secondary side switch.
  • the primary side switch and the secondary side switch may be turned on simultaneously, which causes a short circuit in the synchronous rectification device.
  • additional power loss and unnecessary electromagnetic interference may occur, and elements in the synchronous rectification device may be damaged. Consequently, the synchronous rectification device cannot operate properly.
  • the present disclosure provides a synchronous rectification device, adapted to control a conversion circuit.
  • the conversion circuit includes a primary side coil and a secondary side coil, the primary side coil is configured to receive input power, and the secondary side coil is configured to generate inductive power in response to the input power.
  • the synchronous rectification device includes a first control circuit, a secondary side switch, an isolation coupling element, and a second control circuit.
  • the first control circuit is configured to provide a first control signal.
  • the secondary side switch is configured to generate an ON signal and an OFF signal according to the inductive power.
  • the isolation coupling element includes a receiving side and a reaction side.
  • the receiving side is configured to receive the first control signal.
  • the reaction side is configured to generate a coupling signal in response to the first control signal.
  • the second control circuit is configured to output a second control signal according to the coupling signal, the ON signal, and the OFF signal to adjust the inductive power.
  • the secondary side switch is configured to be turned on or off according to the second control signal to adjust the inductive power.
  • the synchronous rectification device further includes a primary side switch.
  • the primary side switch is configured to be turned on or off according to the first control signal. When the primary side switch is on, the secondary side switch is off
  • the second control circuit adjusts the second control signal according to the OFF signal to turn off the secondary side switch.
  • the second control circuit includes a level generating circuit.
  • the level generating circuit is configured to provide a judgment level for the second control circuit to adjust the second control signal.
  • the level generating circuit adjusts the judgment level to a first level in response to the coupling signal.
  • the level generating circuit adjusts the judgment level to a second level in response to the ON signal.
  • the second control circuit when the judgment level is the first level, adjusts the second control signal according to the ON signal to turn on the secondary side switch.
  • the synchronous rectification device further includes a counting circuit.
  • the counting circuit is configured to adjust the judgment level according to a counting time.
  • the counting circuit when a duration during which the judgment level is the first level exceeds the counting time, the counting circuit adjusts the judgment level to the second level.
  • a synchronous rectification device method includes: converting input power into inductive power according to a first control signal; generating an ON signal and an OFF signal according to the inductive power; generating a coupling signal in response to the first control signal; outputting a second control signal according to the coupling signal, the ON signal, and the OFF signal; and adjusting the inductive power according to the second control signal.
  • the synchronous rectification device method further includes adjusting the second control signal according to a judgment level, where the judgment level is adjusted to a first level in response to the coupling signal, and the judgment level is adjusted to a second level in response to the ON signal.
  • the synchronous rectification device method further includes adjusting the judgment level according to a counting time, where when a duration during which the judgment level is the first level exceeds the counting time, the judgment level is adjusted to the second level.
  • the second control signal is output according to the coupling signal, the ON signal, and the OFF signal to adjust the inductive power.
  • the synchronous rectification device can prevent a short circuit case caused when the primary side switch and the secondary side switch are turned on simultaneously.
  • the synchronous rectification device and the method thereof further include adjusting the judgment level according to the counting time. Therefore, the synchronous rectification device has a reset function.
  • FIG. 1 is a block diagram of a synchronous rectification device according to some embodiments of the present disclosure
  • FIG. 2 is a circuit diagram of a synchronous rectification device according to some embodiments of the present disclosure
  • FIG. 3 is a signal diagram of a synchronous rectification device according to some embodiments of the present disclosure.
  • FIG. 4 is a signal diagram of an inducting voltage according to some embodiments of the present disclosure.
  • FIG. 5 is a signal diagram of a counting time according to some embodiments of the present disclosure.
  • FIG. 6 is a flowchart of a synchronous rectification method according to some embodiments of the present disclosure.
  • Coupled may be used to represent that two or more elements are either in direct physical or electrical contact, or may mean that two or more elements are not in direct contact with each other but yet still co-operate or interact with each other.
  • FIG. 1 is a block diagram of a synchronous rectification device 100 according to some embodiments of the present disclosure.
  • a power supplier 10 includes a conversion circuit 20 and a synchronous rectification device 100 .
  • the conversion circuit 20 is configured to receive input power Sin and generate inductive power S out in response to the input power Sin, and the synchronous rectification device 100 is adapted to control the conversion circuit 20 .
  • the synchronous rectification device 100 includes a secondary side switch 120 , a first control circuit 200 , a second control circuit 300 , and an isolation coupling element 400 .
  • the first control circuit 200 and the second control circuit 300 are separately coupled to the conversion circuit 20 , and the isolation coupling element 400 is coupled between the first control circuit 200 and the second control circuit 300 .
  • the first control circuit 200 and the second control circuit 300 are configured to control the conversion circuit 20 , so that the conversion circuit 20 can convert the input power Sin into the inductive power S out .
  • the first control circuit 200 provides a first control signal S SW to control the conversion circuit 20 , and the conversion circuit 20 receives the input power S in according to the first control signal S SW .
  • the second control circuit 300 outputs a second control signal S SR to control the conversion circuit 20 , and the conversion circuit 20 generates the inductive power S out according to the second control signal S SR .
  • the secondary side switch 120 generates an ON signal S ON and an OFF signal S OFF in response to the inductive power S out .
  • the isolation coupling element 400 is configured to generate a coupling signal S CO in response to the first control signal S SW .
  • the second control signal S SR output by the second control circuit 300 adjusts the inductive power S out by using the secondary side switch 120 .
  • the second control circuit 300 outputs the second control signal S SR according to the coupling signal S CO , the ON signal S ON , and the OFF signal S OFF .
  • the first control circuit 200 controls the second control circuit 300 by using the isolation coupling element 400 and the conversion circuit 20 .
  • the power supplier 10 operates in, for example but not limited to, a situation in which an alternating current (AC) is converted to a direct current (DC).
  • the power supplier 10 further includes a rectification circuit (not shown).
  • the rectification circuit is configured to convert an externally input AC power (not shown) into a DC input power S in for the conversion circuit 20 to receive.
  • the input power S in and the inductive power S out processed by the conversion circuit 20 are DC power.
  • the conversion circuit 20 includes a primary side coil L 1 and a secondary side coil L 2 .
  • the primary side coil L 1 is configured to receive input power S in
  • the secondary side coil L 2 is configured to generate inductive power S out in response to the input power S in .
  • Energy conversion between the primary side coil L 1 and the secondary side coil L 2 is implemented by electromagnetic induction. Specifically, when the primary side coil L 1 receives the input power S in according to the first control signal S SW , the inductive power S out generated by the secondary side coil L 2 in response to the input power S in gradually decreases. On the contrary, when the primary side coil L 1 does not receive the input power S in according to the first control signal S SW , the inductive power S out generated by the secondary side coil L 2 in response to the input power S in gradually increases.
  • FIG. 2 is a circuit diagram of a synchronous rectification device 100 according to some embodiments of the present disclosure.
  • a power supplier 10 includes two input ends N in .
  • the two input ends N in are configured to receive input power S in
  • a primary side coil L 1 is configured to transfer energy to a secondary side coil L 2 according to the input power S in .
  • the synchronous rectification device 100 further includes a primary side switch 110 .
  • the primary side switch 110 has a control electrode E g , a first electrode E d , and a second electrode E s .
  • the control electrode E g of the primary side switch 110 is coupled to a first control circuit 200 .
  • the primary side coil L 1 is coupled between one end of the two input ends N in and the first electrode E d .
  • the other end of the two input ends N in is coupled to the second electrode E s .
  • the primary side switch 110 is turned on or off according to a first control signal S SW .
  • the control electrode E g turns on or off the first electrode E d and the second electrode E s of the primary side switch 110 according to a change of the first control signal S SW .
  • the primary side coil L 1 receives the input power S in .
  • the primary side coil L 1 does not receive the input power S in .
  • the first control signal S SW output by the first control circuit 200 controls the primary side coil L 1 by using the primary side switch 110 .
  • FIG. 3 is a signal diagram of a synchronous rectification device 100 according to some embodiments of the present disclosure.
  • a horizontal axis of the signal diagram is time T
  • a vertical axis of the signal diagram is a first control voltage V SW , a coupling voltage V CO , a judgment level V FL , an inducting voltage V SE , and a second control voltage V SR .
  • the first control circuit 200 is a pulse width modulation (PWM) controller
  • the first control signal S SW is a periodic square wave.
  • the first control signal S SW for each cycle is composed of a high level and a low level, and a duration of each cycle is fixed.
  • the first control circuit 200 controls ratios of the high level and the low level respectively in the duration of each cycle. According to some embodiments, when the first control signal S SW is at a high level, the primary side switch 100 is on.
  • the power supplier 10 includes two output ends N out .
  • the two output ends N out are configured to output the inductive power S out
  • the secondary side coil L 2 is configured to receive the energy transferred by the primary side coil L 1 to generate the input power S out .
  • the synchronous rectification device 100 further includes a secondary side diode D 2 .
  • the secondary side switch 120 has a control end N g , a first end N d , and a second end N s .
  • the secondary side diode D 2 is coupled between the first end N d and the second end N s of the secondary side switch 120 .
  • the control end N g , the first end N d , and the second end N s of the secondary side switch 120 are separately coupled to the second control circuit 300 .
  • the secondary side coil L 2 is coupled between one end of the two output ends N out and the first end N d .
  • the other end of the two output ends N out is coupled to the second end N s .
  • the secondary side switch 120 is turned on or off according to the second control signal S SR .
  • the control end N g turns on or off the first end N d and the second end N s of the secondary side switch 120 according to a change of the second control signal S SR .
  • the secondary side diode D 2 is configured to enable the inductive power S out to flow between the first end N d and the second end N s when the secondary side switch 120 is turned off.
  • the secondary side diode D 2 is a parasitic element of the secondary side switch 120 .
  • the first control circuit 200 controls the second control circuit 300 by using the isolation coupling element 400 and the conversion circuit 20 , and therefore, a time for which the second control signal S SR enables the secondary side switch 120 to be on does not overlap a time for which the first control signal S SW enables the primary side switch 110 to be on. In other words, when the primary side switch 110 is on, the secondary side switch 120 is off. Therefore, the synchronous rectification device 100 can prevent a short circuit case caused when the primary side switch 110 and the secondary side switch 120 are turned on simultaneously.
  • FIG. 4 is a signal diagram of an inducting voltage V SE according to some embodiments of the present disclosure.
  • a horizontal axis of the signal diagram is time T, and a vertical axis of the signal diagram is a first control voltage V SW , an operating voltage V DS , an inducting voltage V SE , and a second control voltage V SR .
  • the secondary side switch 120 has the operating voltage VDS.
  • the operating voltage V DS is a potential difference between the first end N d and the second end N s , and varies under an impact of the inductive power S out .
  • the secondary side switch 120 when the inductive power S out passes through the secondary side switch 120 or the secondary side diode D 2 , charge accumulated between the first end N d and the second end N s of the secondary side switch 120 increases or decreases along a direction of current of the inductive power S out , and therefore, a magnitude of the operating voltage V DS varies with the inductive power S out .
  • the operating voltage V DS meets one of a plurality of inducting voltages V SE (an ON voltage V ON and an OFF voltage V OFF are both inducting voltages V SE )
  • the secondary side switch 120 When the operating voltage V DS meets one of a plurality of inducting voltages V SE (an ON voltage V ON and an OFF voltage V OFF are both inducting voltages V SE ), the secondary side switch 120 generates a corresponding ON signal S ON or OFF signal S OFF .
  • the secondary side switch 120 When the operating voltage V DS meets the corresponding ON voltage V ON , the secondary side switch 120 generates the corresponding ON signal S ON . When the operating voltage V DS meets the corresponding OFF voltage V OFF , the secondary side switch 120 generates the corresponding OFF signal S OFF . It should be particularly noted that the signal diagram of the inducting voltage V SE versus time T is merely used to illustrate a time sequence of the ON signal S ON and the OFF signal S OFF .
  • the secondary side switch is configured to be turned on or off according to the second control signal S SR to adjust the inductive power S out .
  • the secondary side switch 120 is on, since the operating voltage V DS can be regarded as zero, the inductive power S out is not limited by the secondary side switch 120 , and the conversion circuit 20 can normally output the inductive power S out .
  • the primary side switch 110 is turned off, the inductive power S out is limited by the secondary side diode D 2 , and therefore, the conversion circuit 20 cannot normally output the inductive power S out .
  • the isolation coupling element 400 includes a receiving side 410 and a reaction side 420 .
  • the receiving side 410 is coupled between the first control circuit 200 a grounding end GND, and the reaction side 420 is coupled between the second control circuit 300 and a reference potential end P 1 .
  • the receiving side 410 is configured to receive the first control signal S SW .
  • the reaction side 420 is configured to generate a coupling signal Sco in response the first control signal Ssw.
  • the isolation coupling element 400 is configured to transfer the first control signal S SW output by the first control circuit 200 to the second control circuit 300 in the form of the coupling signal S CO .
  • the reaction side 420 When the first control signal Ssw flowing through the receiving side 410 meets a preset threshold of the isolation coupling element 400 , the reaction side 420 generates the coupling signal Sco corresponding to the first control signal S SW , and the reaction side 420 outputs the coupling signal S CO to the second control circuit 300 .
  • the reaction side 420 when the first control signal S SW is at a high level, the reaction side 420 generates the coupling signal S CO , where a duration of the coupling signal S CO corresponds to a duration during which the first control signal S SW is at a high level.
  • the isolation coupling element 400 is configured to isolate the first control circuit 200 from the second control circuit 300 , and to isolate the primary side switch 110 from the secondary side switch 120 . Therefore, the isolation coupling element 400 prevents mutual interference between the primary side switch 110 and the secondary side switch 120 due to an abnormal surge.
  • the isolation coupling element 400 is an optical coupler.
  • the second control circuit 300 outputs the second control signal S SR according to the coupling signal Sco, the ON signal S ON , and the OFF signal S OFF .
  • the coupling signal S CO and the ON signal S ON are configured to drive the second control circuit 300 to start to output the second control signal S SR .
  • the OFF signal S OFF is configured to drive the second control circuit 300 to stop outputting the second control signal S SR . In other words, when the second control circuit 300 receives the OFF signal S OFF , the second control circuit 300 stops outputting the second control signal S SR , and the secondary side switch 120 is thus off.
  • the second control circuit 300 further includes a level generating circuit 310 .
  • the level generating circuit 310 is configured to provide a judgment level V FL used to adjust the second control signal S SR for the second control circuit 300 .
  • the level generating circuit 310 adjusts the judgment level V FL to a first level F 1 in response to the coupling signal S CO .
  • the level generating circuit 310 adjusts the judgment level V FL to a second level F 2 in response to the ON signal S ON .
  • the second control circuit 300 when the judgment level V FL is the first level F 1 , the second control circuit 300 adjusts the second control signal S SR according to the ON signal S ON to turn on the secondary side switch 120 .
  • the second control circuit 300 needs to receive the ON signal S ON and detect that the judgment level V FL is the first level F 1 , the second control circuit 300 starts to output the second control signal S SR , and the secondary side switch 120 is on according to the second control signal S SR .
  • the second control circuit 300 needs to verify the coupling signal S CO transferred by the first control circuit 200 by using the isolation coupling element 400 and the ON signal S ON transferred by the conversion circuit 20 . Therefore, the synchronous rectification device 100 can prevent a short circuit case caused when the primary side switch 110 and the secondary side switch 120 are turned on simultaneously.
  • the level generating circuit 310 when the level generating circuit 310 receives the coupling signal S CO , the level generating circuit 310 switches the judgment level V FL from the second level F 2 to the first level F 1 . After the level generating circuit 310 receives the ON signal S ON and the second control circuit 300 starts to output the second control signal S SR to turn on the secondary side switch 120 , the level generating circuit 310 switches the judgment level V FL from the first level F 1 to the second level F 2 .
  • FIG. 5 is a signal diagram of a counting time T 1 according to some embodiments of the present disclosure.
  • the synchronous rectification device 100 further includes a counting circuit 500 coupled to the level generating circuit 310 .
  • the counting circuit 500 is configured to adjust the judgment level V FL according to a counting time T 1 .
  • the counting circuit 500 adjusts the judgment level V FL to the second level F 2 .
  • the judgment level V FL is always the first level F 1 , the secondary side switch 120 is easily to be incorrectly turned on due to an incorrect ON signal S ON . Therefore, the counting circuit 500 adjusts the judgment level V FL from the first level F 1 to the second level F 2 to achieve a reset function of the synchronous rectification device 100 .
  • FIG. 6 is a flowchart of a synchronous rectification method according to some embodiments of the present disclosure.
  • the synchronous rectification method includes the following steps:
  • Step S 100 Convert input power S in into inductive power S out according to a first control signal S SW .
  • Step S 120 Generate an ON signal S ON and an OFF signal S OFF according to the inductive power S out .
  • Step S 140 Generate a coupling signal Sco in response to the first control signal S SW .
  • Step S 160 Output a second control signal S SR according to the coupling signal S CO , the ON signal S ON , and the OFF signal S OFF .
  • Step S 180 Adjust the inductive power S out according to the second control signal S SR .
  • the synchronous rectification method further includes: adjusting the second control signal S SR according to a judgment level V FL , where the judgment level V FL is adjusted to a first level F 1 in response to the coupling signal S CO and the judgment level V FL is adjusted to a second level F 2 in response to the ON signal S ON .
  • the synchronous rectification method further includes: adjusting the judgment level V FL according to a counting time T 1 , where when a duration during which the judgment level V FL is the first level F 1 exceeds the counting time T 1 , the judgment level V FL is adjusted to the second level F 2 .
  • the second control signal S S R is output according to the coupling signal Sco, the ON signal S ON , and the OFF signal S OFF to adjust the inductive power S out .
  • the synchronous rectification device 100 can prevent a short circuit case caused when the primary side switch 100 and the secondary side switch 120 are turned on simultaneously.
  • the synchronous rectification device 100 and the method thereof further include adjusting the judgment level V FL according to the counting time T 1 . Therefore, the synchronous rectification device 100 has a reset function.

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Dc-Dc Converters (AREA)
  • Rectifiers (AREA)

Abstract

A synchronous rectification device is adapted to control a conversion circuit, where he conversion circuit includes: a primary side coil, configured to receive input power; and a secondary side coil, configured to generate inductive power in response to the input power. The synchronous rectification device includes: a first control circuit, configured to provide a first control signal to control the primary side coil; a secondary side switch, configured to generate an ON signal and an OFF signal according to the inductive power; an isolation coupling element; and a second control circuit. The isolation coupling element includes: a receiving side, configured to receive the first control signal; and a reaction side, configured to generate a coupling signal in response to the first control signal. The second control circuit outputs a second control signal according to the coupling signal, the ON signal, and the OFF signal to adjust the inductive power.

Description

    CROSS-REFERENCE TO RELATED APPLICATION
  • This non-provisional application claims priority under 35 U.S.C. § 119(a) to Patent Application No. 107142566 filed in Taiwan, R.O.C. on Nov. 28, 2018, the entire contents of which are hereby incorporated by reference.
    • BACKGROUND Technical Field
  • The present disclosure relates to the field of power conversion, and in particular, to a synchronous rectification device and a method thereof.
    • Related Art
  • With the progress and development of technologies, electronic products become increasingly diverse, and different electronic products need to operate at different voltages or different currents. As a result, many different power supplies have been developed to meet needs, and to facilitate the increasingly flourishing of the power conversion technology. Therefore, the power conversion technology belongs to a relatively important part in the electronics industry.
  • Currently, in the power supplies, to achieve a high efficiency and low loss rectification function, a synchronous rectification device has become an important and indispensable core part. The same as other types of rectification devices do, the synchronous rectification device includes a primary side switch and a secondary side switch. However, in the conventional synchronous rectification device, due to a parasitic element or a signal surge in a circuit, the primary side switch and the secondary side switch may be turned on simultaneously, which causes a short circuit in the synchronous rectification device. When a short circuit occurs in the synchronous rectification device, additional power loss and unnecessary electromagnetic interference may occur, and elements in the synchronous rectification device may be damaged. Consequently, the synchronous rectification device cannot operate properly.
    • SUMMARY
  • In view of this, the present disclosure provides a synchronous rectification device, adapted to control a conversion circuit. The conversion circuit includes a primary side coil and a secondary side coil, the primary side coil is configured to receive input power, and the secondary side coil is configured to generate inductive power in response to the input power.
  • The synchronous rectification device includes a first control circuit, a secondary side switch, an isolation coupling element, and a second control circuit. The first control circuit is configured to provide a first control signal. The secondary side switch is configured to generate an ON signal and an OFF signal according to the inductive power. The isolation coupling element includes a receiving side and a reaction side. The receiving side is configured to receive the first control signal. The reaction side is configured to generate a coupling signal in response to the first control signal. The second control circuit is configured to output a second control signal according to the coupling signal, the ON signal, and the OFF signal to adjust the inductive power.
  • According to some embodiments, the secondary side switch is configured to be turned on or off according to the second control signal to adjust the inductive power.
  • According to some embodiments, the synchronous rectification device further includes a primary side switch. The primary side switch is configured to be turned on or off according to the first control signal. When the primary side switch is on, the secondary side switch is off
  • According to some embodiments, the second control circuit adjusts the second control signal according to the OFF signal to turn off the secondary side switch.
  • According to some embodiments, the second control circuit includes a level generating circuit. The level generating circuit is configured to provide a judgment level for the second control circuit to adjust the second control signal.
  • According to some embodiments, the level generating circuit adjusts the judgment level to a first level in response to the coupling signal.
  • According to some embodiments, the level generating circuit adjusts the judgment level to a second level in response to the ON signal.
  • According to some embodiments, when the judgment level is the first level, the second control circuit adjusts the second control signal according to the ON signal to turn on the secondary side switch.
  • According to some embodiments, the synchronous rectification device further includes a counting circuit. The counting circuit is configured to adjust the judgment level according to a counting time.
  • According to some embodiments, when a duration during which the judgment level is the first level exceeds the counting time, the counting circuit adjusts the judgment level to the second level.
  • According to some embodiments, a synchronous rectification device method includes: converting input power into inductive power according to a first control signal; generating an ON signal and an OFF signal according to the inductive power; generating a coupling signal in response to the first control signal; outputting a second control signal according to the coupling signal, the ON signal, and the OFF signal; and adjusting the inductive power according to the second control signal.
  • According to some embodiments, the synchronous rectification device method further includes adjusting the second control signal according to a judgment level, where the judgment level is adjusted to a first level in response to the coupling signal, and the judgment level is adjusted to a second level in response to the ON signal.
  • According to some embodiments, the synchronous rectification device method further includes adjusting the judgment level according to a counting time, where when a duration during which the judgment level is the first level exceeds the counting time, the judgment level is adjusted to the second level.
  • In conclusion, according to the synchronous rectification device and the method thereof of the present disclosure, the second control signal is output according to the coupling signal, the ON signal, and the OFF signal to adjust the inductive power. The synchronous rectification device can prevent a short circuit case caused when the primary side switch and the secondary side switch are turned on simultaneously. In some embodiments, the synchronous rectification device and the method thereof further include adjusting the judgment level according to the counting time. Therefore, the synchronous rectification device has a reset function.
    • BRIEF DESCRIPTION OF THE DRAWINGS
  • FIG. 1 is a block diagram of a synchronous rectification device according to some embodiments of the present disclosure;
  • FIG. 2 is a circuit diagram of a synchronous rectification device according to some embodiments of the present disclosure;
  • FIG. 3 is a signal diagram of a synchronous rectification device according to some embodiments of the present disclosure;
  • FIG. 4 is a signal diagram of an inducting voltage according to some embodiments of the present disclosure;
  • FIG. 5 is a signal diagram of a counting time according to some embodiments of the present disclosure; and
  • FIG. 6 is a flowchart of a synchronous rectification method according to some embodiments of the present disclosure.
    •  DETAILED DESCRIPTION
  • In the present disclosure, the word “coupling” and derivatives thereof may be used. In some embodiments, “coupling” may be used to represent that two or more elements are either in direct physical or electrical contact, or may mean that two or more elements are not in direct contact with each other but yet still co-operate or interact with each other.
  • FIG. 1 is a block diagram of a synchronous rectification device 100 according to some embodiments of the present disclosure. In some embodiments, a power supplier 10 includes a conversion circuit 20 and a synchronous rectification device 100. The conversion circuit 20 is configured to receive input power Sin and generate inductive power Sout in response to the input power Sin, and the synchronous rectification device 100 is adapted to control the conversion circuit 20.
  • Still refer to FIG. 1, the synchronous rectification device 100 includes a secondary side switch 120, a first control circuit 200, a second control circuit 300, and an isolation coupling element 400. The first control circuit 200 and the second control circuit 300 are separately coupled to the conversion circuit 20, and the isolation coupling element 400 is coupled between the first control circuit 200 and the second control circuit 300. The first control circuit 200 and the second control circuit 300 are configured to control the conversion circuit 20, so that the conversion circuit 20 can convert the input power Sin into the inductive power Sout. The first control circuit 200 provides a first control signal SSW to control the conversion circuit 20, and the conversion circuit 20 receives the input power Sin according to the first control signal SSW. The second control circuit 300 outputs a second control signal SSR to control the conversion circuit 20, and the conversion circuit 20 generates the inductive power Sout according to the second control signal SSR. In addition, the secondary side switch 120 generates an ON signal SON and an OFF signal SOFF in response to the inductive power Sout. The isolation coupling element 400 is configured to generate a coupling signal SCO in response to the first control signal SSW. Specifically, the second control signal SSR output by the second control circuit 300 adjusts the inductive power Sout by using the secondary side switch 120. The second control circuit 300 outputs the second control signal SSR according to the coupling signal SCO, the ON signal SON, and the OFF signal SOFF.
  • Based on the above, operations between the first control circuit 200 and the second control circuit 300 should be specifically noted. The first control circuit 200 controls the second control circuit 300 by using the isolation coupling element 400 and the conversion circuit 20.
  • In some embodiments, the power supplier 10 operates in, for example but not limited to, a situation in which an alternating current (AC) is converted to a direct current (DC). The power supplier 10 further includes a rectification circuit (not shown). The rectification circuit is configured to convert an externally input AC power (not shown) into a DC input power Sin for the conversion circuit 20 to receive. The input power Sin and the inductive power Sout processed by the conversion circuit 20 are DC power.
  • Still refer to FIG. 1, in some embodiments, the conversion circuit 20 includes a primary side coil L1 and a secondary side coil L2. The primary side coil L1 is configured to receive input power Sin, and the secondary side coil L2 is configured to generate inductive power Sout in response to the input power Sin. Energy conversion between the primary side coil L1 and the secondary side coil L2 is implemented by electromagnetic induction. Specifically, when the primary side coil L1 receives the input power Sin according to the first control signal SSW, the inductive power Sout generated by the secondary side coil L2 in response to the input power Sin gradually decreases. On the contrary, when the primary side coil L1 does not receive the input power Sin according to the first control signal SSW, the inductive power Sout generated by the secondary side coil L2 in response to the input power Sin gradually increases.
  • FIG. 2 is a circuit diagram of a synchronous rectification device 100 according to some embodiments of the present disclosure. In some embodiments, a power supplier 10 includes two input ends Nin. The two input ends Nin are configured to receive input power Sin, and a primary side coil L1 is configured to transfer energy to a secondary side coil L2 according to the input power Sin.
  • Still refer to FIG. 2, in some embodiments, the synchronous rectification device 100 further includes a primary side switch 110. The primary side switch 110 has a control electrode Eg, a first electrode Ed, and a second electrode Es. The control electrode Eg of the primary side switch 110 is coupled to a first control circuit 200. The primary side coil L1 is coupled between one end of the two input ends Nin and the first electrode Ed. The other end of the two input ends Nin is coupled to the second electrode Es. The primary side switch 110 is turned on or off according to a first control signal SSW. Specifically, the control electrode Eg turns on or off the first electrode Ed and the second electrode Es of the primary side switch 110 according to a change of the first control signal SSW. Moreover, when the first electrode Ed and the second electrode Es of the primary side switch 110 are on, the primary side coil L1 receives the input power Sin. When the first electrode Ed and the second electrode Es of the primary side switch 110 are off, the primary side coil L1 does not receive the input power Sin. In other words, the first control signal SSW output by the first control circuit 200 controls the primary side coil L1 by using the primary side switch 110.
  • FIG. 3 is a signal diagram of a synchronous rectification device 100 according to some embodiments of the present disclosure. A horizontal axis of the signal diagram is time T, and a vertical axis of the signal diagram is a first control voltage VSW, a coupling voltage VCO, a judgment level VFL, an inducting voltage VSE, and a second control voltage VSR. In some embodiments, the first control circuit 200 is a pulse width modulation (PWM) controller, and the first control signal SSW is a periodic square wave. The first control signal SSW for each cycle is composed of a high level and a low level, and a duration of each cycle is fixed. The first control circuit 200 controls ratios of the high level and the low level respectively in the duration of each cycle. According to some embodiments, when the first control signal SSW is at a high level, the primary side switch 100 is on.
  • Still refer to FIG. 2, in some embodiments, the power supplier 10 includes two output ends Nout. The two output ends Nout are configured to output the inductive power Sout, and the secondary side coil L2 is configured to receive the energy transferred by the primary side coil L1 to generate the input power Sout.
  • Still refer to FIG. 2, in some embodiments, the synchronous rectification device 100 further includes a secondary side diode D2. The secondary side switch 120 has a control end Ng, a first end Nd, and a second end Ns. The secondary side diode D2 is coupled between the first end Nd and the second end Ns of the secondary side switch 120. The control end Ng, the first end Nd, and the second end Ns of the secondary side switch 120 are separately coupled to the second control circuit 300. The secondary side coil L2 is coupled between one end of the two output ends Nout and the first end Nd. The other end of the two output ends Nout is coupled to the second end Ns. The secondary side switch 120 is turned on or off according to the second control signal SSR. Specifically, the control end Ng turns on or off the first end Nd and the second end Ns of the secondary side switch 120 according to a change of the second control signal SSR. The secondary side diode D2 is configured to enable the inductive power Sout to flow between the first end Nd and the second end Ns when the secondary side switch 120 is turned off. According to some embodiments, the secondary side diode D2 is a parasitic element of the secondary side switch 120.
  • In some embodiments, the first control circuit 200 controls the second control circuit 300 by using the isolation coupling element 400 and the conversion circuit 20, and therefore, a time for which the second control signal SSR enables the secondary side switch 120 to be on does not overlap a time for which the first control signal SSW enables the primary side switch 110 to be on. In other words, when the primary side switch 110 is on, the secondary side switch 120 is off. Therefore, the synchronous rectification device 100 can prevent a short circuit case caused when the primary side switch 110 and the secondary side switch 120 are turned on simultaneously.
  • Referring to FIG. 2 and FIG. 4 together, FIG. 4 is a signal diagram of an inducting voltage VSE according to some embodiments of the present disclosure. A horizontal axis of the signal diagram is time T, and a vertical axis of the signal diagram is a first control voltage VSW, an operating voltage VDS, an inducting voltage VSE, and a second control voltage VSR. In some embodiments, the secondary side switch 120 has the operating voltage VDS. The operating voltage VDS is a potential difference between the first end Nd and the second end Ns, and varies under an impact of the inductive power Sout. Specifically, when the inductive power Sout passes through the secondary side switch 120 or the secondary side diode D2, charge accumulated between the first end Nd and the second end Ns of the secondary side switch 120 increases or decreases along a direction of current of the inductive power Sout, and therefore, a magnitude of the operating voltage VDS varies with the inductive power Sout. When the operating voltage VDS meets one of a plurality of inducting voltages VSE (an ON voltage VON and an OFF voltage VOFF are both inducting voltages VSE), the secondary side switch 120 generates a corresponding ON signal SON or OFF signal SOFF. When the operating voltage VDS meets the corresponding ON voltage VON, the secondary side switch 120 generates the corresponding ON signal SON. When the operating voltage VDS meets the corresponding OFF voltage VOFF, the secondary side switch 120 generates the corresponding OFF signal SOFF. It should be particularly noted that the signal diagram of the inducting voltage VSE versus time T is merely used to illustrate a time sequence of the ON signal SON and the OFF signal SOFF.
  • Based on the above, in some embodiments, the secondary side switch is configured to be turned on or off according to the second control signal SSR to adjust the inductive power Sout. When the secondary side switch 120 is on, since the operating voltage VDS can be regarded as zero, the inductive power Sout is not limited by the secondary side switch 120, and the conversion circuit 20 can normally output the inductive power Sout. When the primary side switch 110 is turned off, the inductive power Sout is limited by the secondary side diode D2, and therefore, the conversion circuit 20 cannot normally output the inductive power Sout.
  • Still refer to FIG. 2 and FIG. 3, in some embodiments, the isolation coupling element 400 includes a receiving side 410 and a reaction side 420. The receiving side 410 is coupled between the first control circuit 200 a grounding end GND, and the reaction side 420 is coupled between the second control circuit 300 and a reference potential end P1. The receiving side 410 is configured to receive the first control signal SSW. The reaction side 420 is configured to generate a coupling signal Sco in response the first control signal Ssw. Specifically, the isolation coupling element 400 is configured to transfer the first control signal SSW output by the first control circuit 200 to the second control circuit 300 in the form of the coupling signal SCO. When the first control signal Ssw flowing through the receiving side 410 meets a preset threshold of the isolation coupling element 400, the reaction side 420 generates the coupling signal Sco corresponding to the first control signal SSW, and the reaction side 420 outputs the coupling signal SCO to the second control circuit 300. According to some embodiments, when the first control signal SSW is at a high level, the reaction side 420 generates the coupling signal SCO, where a duration of the coupling signal SCO corresponds to a duration during which the first control signal SSW is at a high level. Based on the above, in some embodiments, the isolation coupling element 400 is configured to isolate the first control circuit 200 from the second control circuit 300, and to isolate the primary side switch 110 from the secondary side switch 120. Therefore, the isolation coupling element 400 prevents mutual interference between the primary side switch 110 and the secondary side switch 120 due to an abnormal surge. According to some embodiments, the isolation coupling element 400 is an optical coupler.
  • Still refer to FIG. 2 and FIG. 3, in some embodiments, the second control circuit 300 outputs the second control signal SSR according to the coupling signal Sco, the ON signal SON, and the OFF signal SOFF. The coupling signal SCO and the ON signal SON are configured to drive the second control circuit 300 to start to output the second control signal SSR. The OFF signal SOFF is configured to drive the second control circuit 300 to stop outputting the second control signal SSR. In other words, when the second control circuit 300 receives the OFF signal SOFF, the second control circuit 300 stops outputting the second control signal SSR, and the secondary side switch 120 is thus off.
  • Based on the above, in some embodiments, the second control circuit 300 further includes a level generating circuit 310. The level generating circuit 310 is configured to provide a judgment level VFL used to adjust the second control signal SSR for the second control circuit 300. The level generating circuit 310 adjusts the judgment level VFL to a first level F1 in response to the coupling signal SCO. The level generating circuit 310 adjusts the judgment level VFL to a second level F2 in response to the ON signal SON.
  • According to some embodiments, when the judgment level VFL is the first level F1, the second control circuit 300 adjusts the second control signal SSR according to the ON signal SON to turn on the secondary side switch 120. In other words, when the second control circuit 300 needs to receive the ON signal SON and detect that the judgment level VFL is the first level F1, the second control circuit 300 starts to output the second control signal SSR, and the secondary side switch 120 is on according to the second control signal SSR. The second control circuit 300 needs to verify the coupling signal SCO transferred by the first control circuit 200 by using the isolation coupling element 400 and the ON signal SON transferred by the conversion circuit 20. Therefore, the synchronous rectification device 100 can prevent a short circuit case caused when the primary side switch 110 and the secondary side switch 120 are turned on simultaneously.
  • It should be specifically noted that, in some embodiments, when the level generating circuit 310 receives the coupling signal SCO, the level generating circuit 310 switches the judgment level VFL from the second level F2 to the first level F1. After the level generating circuit 310 receives the ON signal SON and the second control circuit 300 starts to output the second control signal SSR to turn on the secondary side switch 120, the level generating circuit 310 switches the judgment level VFL from the first level F1 to the second level F2.
  • FIG. 5 is a signal diagram of a counting time T1 according to some embodiments of the present disclosure. The synchronous rectification device 100 further includes a counting circuit 500 coupled to the level generating circuit 310. The counting circuit 500 is configured to adjust the judgment level VFL according to a counting time T1. When a duration during which the judgment level VFL is the first level F1 exceeds the counting time T1, the counting circuit 500 adjusts the judgment level VFL to the second level F2. Specifically, when the judgment level VFL is always the first level F1, the secondary side switch 120 is easily to be incorrectly turned on due to an incorrect ON signal SON. Therefore, the counting circuit 500 adjusts the judgment level VFL from the first level F1 to the second level F2 to achieve a reset function of the synchronous rectification device 100.
  • FIG. 6 is a flowchart of a synchronous rectification method according to some embodiments of the present disclosure. In some embodiments, the synchronous rectification method includes the following steps:
  • Step S100: Convert input power Sin into inductive power Sout according to a first control signal SSW.
  • Step S120: Generate an ON signal SON and an OFF signal SOFF according to the inductive power Sout.
  • Step S140: Generate a coupling signal Sco in response to the first control signal SSW.
  • Step S160: Output a second control signal SSR according to the coupling signal SCO, the ON signal SON, and the OFF signal SOFF.
  • Step S180: Adjust the inductive power Sout according to the second control signal SSR.
  • According to some embodiments, the synchronous rectification method further includes: adjusting the second control signal SSR according to a judgment level VFL, where the judgment level VFL is adjusted to a first level F1 in response to the coupling signal SCO and the judgment level VFL is adjusted to a second level F2 in response to the ON signal SON.
  • According to some embodiments, the synchronous rectification method further includes: adjusting the judgment level VFL according to a counting time T1, where when a duration during which the judgment level VFL is the first level F1 exceeds the counting time T1, the judgment level VFL is adjusted to the second level F2.
  • In conclusion, according to the synchronous rectification device 100 and the method thereof of the present disclosure, the second control signal SSR is output according to the coupling signal Sco, the ON signal SON, and the OFF signal SOFF to adjust the inductive power Sout. The synchronous rectification device 100 can prevent a short circuit case caused when the primary side switch 100 and the secondary side switch 120 are turned on simultaneously.
  • In some embodiments, the synchronous rectification device 100 and the method thereof further include adjusting the judgment level VFL according to the counting time T1. Therefore, the synchronous rectification device 100 has a reset function.

Claims (13)

1. A synchronous rectification device, adapted to control a conversion circuit, wherein the conversion circuit comprises a primary side coil and a secondary side coil, the primary side coil is configured to receive an input power, and the secondary side coil is configured to generate an inductive power in response to the input power, and the synchronous rectification device comprises:
a first control circuit, configured to provide a first control signal to control the primary side coil;
a primary side switch, configured to be turned on or off according to the first control signal;
a secondary side switch, configured to generate an ON signal and an OFF signal according to the inductive power, wherein when the primary side switch is on, the secondary side switch is off;
an optical isolation coupling element, comprising:
a receiving side, configured to receive the first control signal; and
a reaction side, configured to generate a coupling signal in response to the first control signal; and
a second control circuit, configured to output a second control signal according to the coupling signal, the ON signal, and the OFF signal to adjust the inductive power, wherein the second control circuit adjusts the second control signal according to the OFF signal to turn off the secondary side switch, and the secondary side switch is configured to be turned on or off according to the second control signal to adjust the inductive power-, wherein within one of a plurality of ON/OFF cycles of the secondary side switch, the second control circuit adjusts the second control signal according to the OFF signal to turn off the secondary side switch.
2. (canceled)
3. (canceled)
4. (canceled)
5. The synchronous rectification device according to claim 1, wherein the second control circuit comprises: a level generating circuit, configured to provide a judgment level for the second control circuit to adjust the second control signal.
6. The synchronous rectification device according to claim 5, wherein the level generating circuit adjusts the judgment level to a first level in response to the coupling signal.
7. The synchronous rectification device according to claim 6, wherein the level generating circuit adjusts the judgment level to a second level in response to the ON signal.
8. The synchronous rectification device according to claim 7, wherein when the judgment level is the first level, the second control circuit adjusts the second control signal according to the ON signal to turn on the secondary side switch.
9. The synchronous rectification device according to claim 7, further comprising: a counting circuit, configured to adjust the judgment level according to a counting time.
10. The synchronous rectification device according to claim 9, wherein when a duration during which the judgment level is the first level exceeds the counting time, the counting circuit adjusts the judgment level to the second level.
11. A synchronous rectification method, comprising:
receiving an input power by using a primary side coil;
generating an inductive power in response to the input power by using a secondary side coil;
generating a first control signal to control the primary side coil by using a first control circuit
turning on or off a primary side switch according to the first control signal;
generating an ON signal and an OFF signal according to the inductive power by using a secondary side switch, wherein when the primary side switch is on, the secondary side switch is off;
generating a coupling signal in response to the first control signal by using an optical isolation coupling element;
outputting a second control signal according to the coupling signal, the ON signal, and the OFF signal by using a second control circuit; and
adjusting the inductive power according to the second control signal-i
wherein the second control circuit adjusts the second control signal according to the OFF signal to turn off the secondary side switch, and the secondary side switch is configured to be turned on or off according to the second control signal to adjust the inductive power;
wherein within one of a plurality of ON/OFF cycles of the secondary side switch, the second control circuit adjusts the second control signal according to the OFF signal to turn off the secondary side switch.
12. The synchronous rectification method according to claim 11, further comprising:
adjusting the second control signal according to a judgment level, wherein the judgment level is adjusted to a first level in response to the coupling signal, and the judgment level is adjusted to a second level in response to the ON signal.
13. The synchronous rectification method according to claim 12, further comprising:
adjusting the judgment level according to a counting time, wherein when a duration during which the judgment level is the first level exceeds the counting time, the judgment level is adjusted to the second level.
US16/258,124 2018-11-28 2019-01-25 Synchronous rectification device and method thereof Active US10666155B1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
TW107142566A TWI692183B (en) 2018-11-28 2018-11-28 Synchronous rectifying apparatus
TW107142566A 2018-11-28
TW107142566 2018-11-28

Publications (2)

Publication Number Publication Date
US10666155B1 US10666155B1 (en) 2020-05-26
US20200169178A1 true US20200169178A1 (en) 2020-05-28

Family

ID=70770012

Family Applications (1)

Application Number Title Priority Date Filing Date
US16/258,124 Active US10666155B1 (en) 2018-11-28 2019-01-25 Synchronous rectification device and method thereof

Country Status (3)

Country Link
US (1) US10666155B1 (en)
CN (1) CN111245244B (en)
TW (1) TWI692183B (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11496058B2 (en) 2020-09-23 2022-11-08 Chicony Power Technology Co., Ltd. Power converter

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20050069326A1 (en) * 2003-09-30 2005-03-31 Stmicroelectronics S.A. Optical coupling device and method for bidirectional data communication over a common signal line
US20050248964A1 (en) * 2004-05-10 2005-11-10 Semiconductor Components Industries, Llc. Power supply controller and method therefor
US20060013022A1 (en) * 2002-04-12 2006-01-19 Jitaru Ionel D High efficiency flyback converter
US20150249398A1 (en) * 2014-03-03 2015-09-03 Nxp B.V. Method for contolling a smpc having a synchronous rectification switch, a smpc and a controller therefor
US20160111961A1 (en) * 2014-10-21 2016-04-21 Power Integrations, Inc. Output-side controller with switching request at relaxation ring extremum
US9755529B2 (en) * 2015-05-06 2017-09-05 Richtek Technology Corporation Flyback power converter and controller and driver thereof
US20180183342A1 (en) * 2016-12-26 2018-06-28 Nxp B.V. Switched mode power supply with reduced delay time
US20180248488A1 (en) * 2017-02-24 2018-08-30 On-Bright Electronics (Shanghai) Co., Ltd. Systems and methods with timing control for synchronization rectifier controllers
US20190149032A1 (en) * 2017-11-10 2019-05-16 Richtek Technology Corporation Zvs control circuit for use in a flyback power converter

Family Cites Families (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7460604B2 (en) 2004-06-03 2008-12-02 Silicon Laboratories Inc. RF isolator for isolating voltage sensing and gate drivers
US7362598B2 (en) 2004-12-17 2008-04-22 Artesyn Technologies, Inc. Synchronous rectifier gate drive shutdown circuit
DE112009004513T5 (en) 2009-03-18 2012-05-31 Murata Manufacturing Co., Ltd. Power factor correction converter
JP5223874B2 (en) 2010-03-09 2013-06-26 株式会社村田製作所 Isolated switching power supply
US9077258B2 (en) * 2011-07-26 2015-07-07 System General Corp. Regulation circuit associated with synchronous rectifier providing cable compensation for the power converter and method thereof
TWI580168B (en) * 2015-05-21 2017-04-21 立錡科技股份有限公司 Power converter with synchronous control function and control method thereof
TWI598719B (en) * 2015-06-11 2017-09-11 通嘉科技股份有限公司 Power supplies and control methods suitable for sequentially transmitting command bits from secondary side to primary side
US20170117813A1 (en) 2015-10-21 2017-04-27 Quanta Computer Inc. Method and system for testing a power supply unit
TWI569562B (en) 2015-11-16 2017-02-01 通嘉科技股份有限公司 Method for controlling a dead time of a secondary side of a power converter
US10868473B2 (en) * 2015-11-30 2020-12-15 Semiconductor Components Industries, Llc Secondary side controlled control circuit for power converter with synchronous rectifier
TWI551023B (en) 2016-01-21 2016-09-21 Isolated power conversion system
CN108063555B (en) 2016-11-07 2020-04-03 台达电子工业股份有限公司 Multi-stage power converter and control method thereof
US10191121B2 (en) 2017-05-31 2019-01-29 Quanta Computer Inc. System and method for voltage regulator self-burn-in test

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20060013022A1 (en) * 2002-04-12 2006-01-19 Jitaru Ionel D High efficiency flyback converter
US20050069326A1 (en) * 2003-09-30 2005-03-31 Stmicroelectronics S.A. Optical coupling device and method for bidirectional data communication over a common signal line
US20050248964A1 (en) * 2004-05-10 2005-11-10 Semiconductor Components Industries, Llc. Power supply controller and method therefor
US20150249398A1 (en) * 2014-03-03 2015-09-03 Nxp B.V. Method for contolling a smpc having a synchronous rectification switch, a smpc and a controller therefor
US20160111961A1 (en) * 2014-10-21 2016-04-21 Power Integrations, Inc. Output-side controller with switching request at relaxation ring extremum
US9755529B2 (en) * 2015-05-06 2017-09-05 Richtek Technology Corporation Flyback power converter and controller and driver thereof
US20180183342A1 (en) * 2016-12-26 2018-06-28 Nxp B.V. Switched mode power supply with reduced delay time
US20180248488A1 (en) * 2017-02-24 2018-08-30 On-Bright Electronics (Shanghai) Co., Ltd. Systems and methods with timing control for synchronization rectifier controllers
US20190149032A1 (en) * 2017-11-10 2019-05-16 Richtek Technology Corporation Zvs control circuit for use in a flyback power converter

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11496058B2 (en) 2020-09-23 2022-11-08 Chicony Power Technology Co., Ltd. Power converter

Also Published As

Publication number Publication date
US10666155B1 (en) 2020-05-26
CN111245244B (en) 2021-08-27
TWI692183B (en) 2020-04-21
CN111245244A (en) 2020-06-05
TW202021249A (en) 2020-06-01

Similar Documents

Publication Publication Date Title
US9054546B2 (en) Primary-side and secondary-side full-bridge switching circuit controller for a magnetic coupling and contactless power transmission apparatus
TWI619342B (en) Converter and control method thereof
US11848603B2 (en) Auxiliary power supply apparatus and method for isolated power converters
US9479060B2 (en) Control circuit, battery power supply device and control method
US9866108B2 (en) PFC shutdown circuit for light load
TW201517489A (en) Isolated switching converters, and switching controllers and controlling methods thereof
CN108933529B (en) Power supply control device and power supply control system
CN107612336A (en) Variable blanking frequency for resonance converter
CN101340155B (en) Apparatus and method for improving light load effect of flyback voltage converter
CN105245112B (en) A kind of adaptive high-accuracy and constant current circuit and Switching Power Supply
TWI590574B (en) Power supply apparatus
CN102377169A (en) Thermal shutdown unit, switch controller including the same, and control method of thermal shutdown protection operation
CN201440636U (en) Limiting circuit with largest conduction duty ratio for power switch tube of switch power supply
TW201709656A (en) Flyback converter
US9407140B2 (en) Voltage detection method and circuit and associated switching power supply
CN110829383B (en) Multi-mode protection circuit of double-winding secondary feedback switching power supply
US11152862B2 (en) Power controllers and control methods for reducing output voltage ripple when line voltage is low
WO2015079580A1 (en) Power-supply device
US10666155B1 (en) Synchronous rectification device and method thereof
TWI729807B (en) Flyback power converter and active clamp snubber and overcharging protection circuit thereof
US9608434B2 (en) Inverter apparatus having primary-side and secondary-side driver circuits driven by respective DC/DC converters and control method thereof
CN103630735A (en) Voltage slope change detection circuit and method
CN103066847B (en) Supply unit and image forming apparatus
CN202794316U (en) Detection circuit for changes of voltage slope
CN112701915A (en) Local Zero Voltage Switching (ZVS) for flyback power converter and method thereof

Legal Events

Date Code Title Description
AS Assignment

Owner name: CHICONY POWER TECHNOLOGY CO., LTD., TAIWAN

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:PENG, TSO-JEN;WANG, SSU-HAO;REEL/FRAME:048140/0909

Effective date: 20190125

FEPP Fee payment procedure

Free format text: ENTITY STATUS SET TO UNDISCOUNTED (ORIGINAL EVENT CODE: BIG.); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

STCF Information on status: patent grant

Free format text: PATENTED CASE

MAFP Maintenance fee payment

Free format text: PAYMENT OF MAINTENANCE FEE, 4TH YEAR, LARGE ENTITY (ORIGINAL EVENT CODE: M1551); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

Year of fee payment: 4