CN113890373A - Self-driving circuit applied to resonant circuit LLC and LLC - Google Patents

Self-driving circuit applied to resonant circuit LLC and LLC Download PDF

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Publication number
CN113890373A
CN113890373A CN202111171931.4A CN202111171931A CN113890373A CN 113890373 A CN113890373 A CN 113890373A CN 202111171931 A CN202111171931 A CN 202111171931A CN 113890373 A CN113890373 A CN 113890373A
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CN
China
Prior art keywords
gate
comparator
llc
tube
circuit
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Pending
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CN202111171931.4A
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Chinese (zh)
Inventor
颜权枫
雷龙
宇文超敏
宋蒙恩
张岩
瞿浩
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Gree Electric Appliances Inc of Zhuhai
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Gree Electric Appliances Inc of Zhuhai
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Priority to CN202111171931.4A priority Critical patent/CN113890373A/en
Publication of CN113890373A publication Critical patent/CN113890373A/en
Pending legal-status Critical Current

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    • 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
    • H02M1/088—Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters for the simultaneous control of series or parallel connected semiconductor devices
    • 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
    • H02M1/32—Means for protecting converters other than automatic disconnection
    • 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

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

Abstract

The application provides a self-driving circuit applied to a resonant circuit LLC and the LLC; the negative input ends of a first comparator and a second comparator in the self-driving circuit are respectively connected with the drain electrode of a rectifying tube of the LLC, and the positive input ends of the first comparator and the second comparator are connected with the source level of the rectifying tube; the output end of the first comparator is respectively connected with the first input end of the first exclusive-OR gate and the first input end of the second exclusive-OR gate; the output end of the second comparator is connected with the second input end of the first exclusive-or gate and the second input end of the second exclusive-or gate; the first input end of the first AND gate is connected with the output end of the first comparator, the second input end of the first AND gate is connected with the output end of the first XOR gate, the first input end of the second AND gate is connected with the output end of the second comparator, and the second input end of the second AND gate is connected with the output end of the second XOR gate; the output ends of the first AND gate and the second AND gate are connected with the gate of the rectifier tube.

Description

Self-driving circuit applied to resonant circuit LLC and LLC
Technical Field
The application relates to the technical field of circuits, in particular to a self-driving circuit applied to a resonant circuit LLC and the LLC.
Background
At present, in the development process of power electronics, the application of low-voltage large-current output has become a very important development direction. The resonant circuit LLC converter with reasonable design can basically realize that the primary side MOSFET always works in a ZVS (zero voltage switching) opening state under the full-range load, thereby improving the system efficiency. In such an occasion, the loss of the rectifier on the secondary side of the transformer accounts for most of the overall loss, and in order to reduce the loss of the rectifier, the synchronous rectifier technology is generally adopted in the low-output voltage occasion at present. If the driving scheme of synchronous rectification is complicated, or an unregulated driver Integrated Circuit (IC) chip is used, the effect of synchronous rectification is affected. The existing synchronous rectification scheme suitable for the LLC generally uses a voltage bias circuit as a drive signal source, and the voltage bias circuit has a complex internal structure logic, involves many devices, and results in a high cost.
Disclosure of Invention
An object of the embodiments of the present application is to provide a self-driving circuit and an LLC applied to a resonant circuit LLC. The specific technical scheme is as follows:
in a first aspect, a self-driving circuit applied to a resonant circuit LLC is provided, the self-driving circuit comprising: the first comparator, the second comparator, the first exclusive-OR gate, the second exclusive-OR gate, the first AND gate and the second AND gate; the negative input ends of the first comparator and the second comparator are respectively connected with the drain electrodes of the rectifying tubes of the LLC, and the grounding ends and the positive input ends of the first comparator and the second comparator are connected with the source electrodes of the rectifying tubes; the output end of the first comparator is respectively connected with the first input end of the first exclusive-or gate and the first input end of the second exclusive-or gate; the output end of the second comparator is respectively connected with the second input end of the first exclusive-or gate and the second input end of the second exclusive-or gate; the first input end of the first AND gate is connected with the output end of the first comparator, the second input end of the first AND gate is connected with the output end of the first XOR gate, the first input end of the second AND gate is connected with the output end of the second comparator, and the second input end of the second AND gate is connected with the output end of the second XOR gate; and the output ends of the first AND gate and the second AND gate are connected with the grid of the rectifier tube.
In a second aspect, a resonant circuit LLC is provided, the LLC comprising: a transformer, the self-driving circuit of the first aspect, and a rectifier tube; the rectifying tube comprises a first rectifying tube and a second rectifying tube; the first end of the secondary side of the transformer is respectively connected with the drain electrode of the first rectifying tube and the negative input end of the first comparator; and the second end of the secondary side of the transformer is respectively connected with the drain electrode of the second rectifying tube and the negative input end of the second comparator.
In a third aspect, there is provided a method for controlling a switch of a rectifier in an LLC based on the self-driving circuit in the first aspect, including: detecting a first voltage at the negative input of the first comparator and a second voltage at the negative input of the second comparator; under the condition that the first voltage and the second voltage are both smaller than 0, controlling the rectifier tube to be closed; under the condition that the first voltage is less than 0 and the second voltage is not less than 0, controlling a rectifier tube corresponding to the first comparator to be conducted; and under the condition that the first voltage is not less than 0 and the second voltage is less than 0, controlling the rectifier tube corresponding to the second comparator to be conducted.
The self-driving circuit in the embodiment of the application comprises the comparator, the exclusive-or gate and the and gate, namely, the self-driving circuit in the embodiment of the application has few devices and simple circuit connection, and can reduce the cost under the condition of ensuring the efficiency. In addition, based on the self-driving circuit, the rectifier tube can perform self-switching according to the level change of the secondary side circuit, and Pulse Width Modulation (PWM) waves are not additionally provided for control, so that the control difficulty of the whole circuit is reduced, and the problem that in the prior art, a voltage bias circuit is used as a driving signal source in the synchronous rectification scheme of the LLC, the internal structure logic of the voltage bias circuit is complex, and more components are caused is solved.
Drawings
FIG. 1 is a circuit diagram of a self-driving circuit according to an embodiment of the present application;
FIG. 2 is one of the circuit schematic diagrams of the LLC of the present application;
FIG. 3 is a second schematic circuit diagram of an LLC of an embodiment of the application;
FIG. 4 is a flowchart of a method for controlling rectification based on a self-driving circuit according to an embodiment of the present application;
FIG. 5 is a synchronous rectification waveform based on a self-driving circuit according to an embodiment of the present application;
fig. 6 is a flowchart of a method for controlling a rectifier switch based on a self-driving circuit according to an embodiment of the present application.
Detailed Description
The technical solutions in the embodiments of the present application will be described below with reference to the drawings in the embodiments of the present application.
An embodiment of the present application provides a self-driving circuit applied to a resonant circuit LLC, as shown in fig. 1, the self-driving circuit includes: a first comparator S1, a second comparator S2, a first exclusive or gate S3, a second exclusive or gate S4, a first and gate S5, and a second and gate S6;
the negative input ends of the first comparator S1 and the second comparator S2 are respectively connected with the drain electrodes of the rectifying tubes of the LLC, and the grounding ends and the positive input ends of the first comparator S1 and the second comparator S2 are connected with the source electrodes of the rectifying tubes;
the output of the first comparator S1 is connected to a first input of a first xor gate S3 and to a first input of a second xor gate S4; the output of the second comparator S2 is connected to a second input of the first xor gate S3 and to a second input of the second xor gate S4;
a first input terminal of the first and gate S5 is connected to an output terminal of the first comparator SA, a second input terminal of the first and gate S5 is connected to an output terminal of the first exclusive or gate S3, a first input terminal of the second and gate S6 is connected to an output terminal of the second comparator S2, and a second input terminal of the second and gate S6 is connected to an output terminal of the second exclusive or gate S4;
the output ends of the first and gate S5 and the second and gate S6 are connected to the gates of the rectifiers.
Based on fig. 1, the detected drain voltage of the secondary synchronous rectifier of the transformer is logically compared with the source voltage, i.e. the secondary GND, and if the logical comparison result is positive, it indicates that the body diode of the synchronous rectifier is turned on, it is recorded as logic "1", otherwise it is recorded as logic "0". The logic result of S1 and the comparison result of the other comparator S2 are input into an exclusive-OR gate comparator. The exclusive-or gate comparator outputs '1' only when the input signals are '1' and '0', and outputs logic '1' only when the input signals are '1' and '0', so as to confirm that the input '1' is the wanted path, and then inputs the exclusive-or output and the comparator output into AND gate logic, and can output logic '1', thereby ensuring that the two paths of rectifying tubes can be correctly turned on and off under the condition of different turning-on.
Therefore, the self-driving circuit in the embodiment of the application comprises the comparator, the exclusive-or gate and the and gate, namely, the self-driving circuit in the embodiment of the application has few devices and simple circuit connection, and the cost can be reduced under the condition of ensuring the efficiency. In addition, based on the self-driving circuit, the rectifier tube can perform self-switching according to the level change of the secondary side circuit, and Pulse Width Modulation (PWM) waves are not additionally provided for control, so that the control difficulty of the whole circuit is reduced, and the problem that in the prior art, a voltage bias circuit is used as a driving signal source in the synchronous rectification scheme of the LLC, the internal structure logic of the voltage bias circuit is complex, and more components are caused is solved.
It should be noted that, in the embodiment of the present application, the VCC supply voltage is a driving voltage value of the rectifier, and when the output is logic "1", the level value is the driving voltage value of the rectifier, so that the switching of the rectifier can be normally controlled. The rectifier tube and the resonant switch tube in the embodiment of the application can be MOSFET tubes.
An embodiment of the present application further provides a resonant circuit LLC, as shown in fig. 2, where the LLC includes: a resonant network circuit, a transformer, a self-driving circuit in fig. 1, a rectifier tube; the rectifier tube comprises a first rectifier tube Q1 and a second rectifier tube Q2;
the resonant network circuit is connected with the primary side of the transformer, and the first end of the secondary side of the transformer is respectively connected with the drain electrode of the first rectifying tube Q1 and the negative input end of the first comparator; the second end of the secondary side of the transformer is respectively connected with the drain electrode of the second rectifying tube Q2 and the negative input end of the second comparator.
As shown in fig. 3, the LLC in the embodiment of the present application further includes a first resonant switching tube Q3, a second resonant switching tube Q4, a first capacitor C1, a second capacitor C2, and a third capacitor C3; the source of the first resonant switching tube Q3 and the drain of the second resonant switching tube Q4 are respectively connected with the first end of the primary side of the transformer; the drain electrode of the first resonant switching tube Q3 is connected with one end of a second capacitor C2, and the other end of the second capacitor C2 is respectively connected with a third capacitor C3 and a second end of the primary side of the transformer; the other end of the third capacitor C3 is connected with the source of the second resonant switching tube Q4; one end of the first capacitor C1 is connected to the drain of the first resonant switch tube, and the other end of the first capacitor is connected to the source of the second resonant switch tube Q4.
In addition, the LLC further comprises a first inductor L1 and a fourth capacitor C4; the first inductor L1 is connected in series between the first end of the primary side of the transformer and the source of the first resonant switching tube Q3.
One end of the fourth capacitor is connected with the secondary side of the transformer, and the other end of the fourth capacitor is connected with the source of the first rectifying tube Q1 and the second rectifying tube Q2.
Further, the LLC further comprises a micro control unit MCU; the MCU comprises a driving circuit and a control circuit; one end of the driving circuit is respectively connected with the grids of the first resonance switch tube and the second resonance switch tube; one end of the control circuit is connected with the other end of the driving circuit, and the control circuit is used for controlling the driving circuit to send driving signals to the first resonance switch tube and the second resonance switch tube so as to control the first resonance switch tube and the second resonance switch tube to be switched on and off.
In addition, the MCU further includes: a sampling circuit and a protection circuit; the protection circuit is connected with the control circuit, and one end of the sampling circuit is connected with the control circuit; the other end of the sampling circuit is respectively connected with the primary side and the secondary side of the transformer and is used for sampling the current of the primary side and the voltage of the secondary side of the transformer.
That is to say, the primary side of the LLC transformer in the embodiment of the present application adopts a half-bridge LLC scheme, which is controlled by an MCU main chip, and the MCU circuit includes a sampling circuit, a control circuit, a driving circuit, and a protection circuit. The half-bridge LLC performs closed-loop control by sampling the output voltage and the primary resonant current of the resonant transformer, drives at a fixed 50% duty ratio after subtracting a fixed dead time, achieves an output voltage preset value by adjusting the driving frequency and ensures the stability of the output voltage through the matching of an output capacitor. And monitoring the output voltage and the resonant current in real time, and if the monitoring value is too high or too low in a short time, adjusting the driving signal or closing the driving signal through the MCU to perform corresponding protection. Further, a synchronous rectification scheme is used at the secondary side direct current output, and the synchronous rectification scheme is controlled by a self-driving circuit built by a separation device. The frequency and the duty ratio of the self-driving circuit for controlling the Q1 and the Q2 depend on the control frequency and the duty ratio of a primary side resonance network of the transformer, the frequency and the duty ratio of the resonance network are induced to an output end of a secondary side through the transformer, the voltage between the source and drain electrodes of the Q1 and the Q2 changes along with the frequency and the duty ratio, the self-driving circuit drives and controls the switch of the Q1 and the Q2 through detecting the voltage between the source and drain electrodes of the Q1 and the Q2, and the rectification purpose is achieved.
In an embodiment of the present application, there is further provided a method for controlling a switch of a rectifier in an LLC based on the self-driving circuit in fig. 1, as shown in fig. 4, the method includes the steps of:
step 402, detecting a first voltage at a negative input end of a first comparator and a second voltage at a negative input end of a second comparator;
step 404, controlling the rectifier tube to be closed under the condition that the first voltage and the second voltage are both less than 0;
step 406, controlling the rectifier tube corresponding to the first comparator to be conducted under the condition that the first voltage is less than 0 and the second voltage is not less than 0;
step 408, controlling the rectifier corresponding to the second comparator to conduct when the first voltage is not less than 0 and the second voltage is less than 0.
It can be seen that, in the embodiment of the present application, when only the first voltage at the negative input end of the first comparator and the second voltage at the negative input end of the second comparator are both low voltages (less than 0), the corresponding rectifying tubes may be controlled to be turned on, and when only one of the voltages is low voltage, the corresponding rectifying tube may be controlled to be turned off.
Referring to fig. 1, the VCC is connected to the supply voltage of the comparator, the D3 and D4 are respectively connected to the drain of the rectifier, such as the MOSFET, the GND is connected to the source of the MOSFET, and the G3 and G4 are respectively connected to the gate of the MOSFET. As shown in fig. 5, when the voltage value at D3 is less than 0V, G3 sends out high level to control the rectifier to turn on, and when the voltage value at D3 is higher than 0V, G3 low level controls the rectifier to turn off, and the same operation states as D4 and G4 are obtained. At times t 1-t 2, D3 and D4 are in the low level state at the same time, and at this time, G3 and G4 are in the low level state, and the two rectifying tubes are turned off at the same time. Based on this, as shown in fig. 6, the method steps of the rectification control process include:
step 602, detecting voltages of D3 and D4;
step 604, determining whether D3 is less than 0, if so, performing step 608, and if not, performing step 602;
step 606, determining whether D4 is less than 0, if less than 0, executing step 608, and if greater than or equal to 0, executing step 602;
step 608, determining whether D3 and D4 are both less than 0; if the determination result is no, go to step 610, and if the determination result is yes, go to step 602;
step 610, determining whether D3 is less than 0 or determining whether D4 is less than 0; if the determination is yes, step 612 is executed, and if the determination is no, step 602 is executed.
Therefore, in the embodiment of the application, based on the self-driving circuit, the rectifier tube performs self-switching according to the level change of the secondary side circuit, and the PWM wave is not required to be additionally provided for control, so that the control difficulty of the whole circuit is reduced.
It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.
All the embodiments in the present specification are described in a related manner, and the same and similar parts among the embodiments may be referred to each other, and each embodiment focuses on the differences from the other embodiments. In particular, for the system embodiment, since it is substantially similar to the method embodiment, the description is simple, and for the relevant points, reference may be made to the partial description of the method embodiment.
The above description is only for the preferred embodiment of the present application, and is not intended to limit the scope of the present application. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application are included in the protection scope of the present application.

Claims (9)

1. A self-driving circuit for application in a resonant circuit LLC, said self-driving circuit comprising: the first comparator, the second comparator, the first exclusive-OR gate, the second exclusive-OR gate, the first AND gate and the second AND gate;
the negative input ends of the first comparator and the second comparator are respectively connected with the drain electrodes of the rectifying tubes of the LLC, and the grounding ends and the positive input ends of the first comparator and the second comparator are connected with the source electrodes of the rectifying tubes;
the output end of the first comparator is respectively connected with the first input end of the first exclusive-or gate and the first input end of the second exclusive-or gate; the output end of the second comparator is respectively connected with the second input end of the first exclusive-or gate and the second input end of the second exclusive-or gate;
the first input end of the first AND gate is connected with the output end of the first comparator, the second input end of the first AND gate is connected with the output end of the first XOR gate, the first input end of the second AND gate is connected with the output end of the second comparator, and the second input end of the second AND gate is connected with the output end of the second XOR gate;
and the output ends of the first AND gate and the second AND gate are connected with the grid of the rectifier tube.
2. A resonant circuit LLC, characterized in that said LLC comprises: a resonant network circuit, a transformer, a self-driving circuit of claim 1, a rectifier tube; the rectifying tube comprises a first rectifying tube and a second rectifying tube;
the resonant network circuit is connected with the primary side of the transformer; the first end of the secondary side of the transformer is respectively connected with the drain electrode of the first rectifying tube and the negative input end of the first comparator; and the second end of the secondary side of the transformer is respectively connected with the drain electrode of the second rectifying tube and the negative input end of the second comparator.
3. The LLC of claim 2 wherein said resonant network circuit comprises a first resonant switching tube, a second resonant switching tube, a first capacitor, a second capacitor, and a third capacitor;
the source electrode of the first resonant switching tube and the drain electrode of the second resonant switching tube are respectively connected with the first end of the primary side of the transformer;
the drain electrode of the first resonant switching tube is connected with one end of the second capacitor, and the other end of the second capacitor is respectively connected with the third capacitor and the second end of the primary side of the transformer; the other end of the third capacitor is connected with the source stage of the second resonant switching tube;
one end of the first capacitor is connected with the drain electrode of the first resonant switching tube, and the other end of the first capacitor is connected with the source electrode of the second resonant switching tube.
4. The LLC of claim 3, wherein said resonant network circuit further comprises: a first inductor;
the first inductor is connected in series between the first end of the primary side of the transformer and the source stage of the first resonant switching tube.
5. The LLC of claim 3, wherein said LLC further comprises a Micro Control Unit (MCU); the MCU comprises a driving circuit and a control circuit;
one end of the driving circuit is respectively connected with the grids of the first resonant switching tube and the second resonant switching tube;
one end of the control circuit is connected with the other end of the driving circuit, and the control circuit is used for controlling the driving circuit to send driving signals to the first resonance switch tube and the second resonance switch tube so as to control the switching of the first resonance switch tube and the second resonance switch tube.
6. The LLC of claim 5, wherein said MCU further comprises: a sampling circuit and a protection circuit; the protection circuit is connected with the control circuit, and one end of the sampling circuit is connected with the control circuit; the other end of the sampling circuit is respectively connected with the primary side and the secondary side of the transformer and is used for sampling the current of the primary side and the voltage of the secondary side of the transformer.
7. The LLC of claim 2, wherein said LLC further comprises a fourth capacitance; one end of the fourth capacitor is connected with the secondary side of the transformer, and the other end of the fourth capacitor is connected with the source of the first rectifying tube and the source of the second rectifying tube.
8. The LLC of claim 2, wherein the voltage values of the supply voltages of said first and second comparators are equal to the drive voltage value of said rectifier.
9. A method for controlling a switch of a rectifier in an LLC based on the self-driving circuit of claim 1, comprising:
detecting a first voltage at the negative input of the first comparator and a second voltage at the negative input of the second comparator;
under the condition that the first voltage and the second voltage are both smaller than 0, controlling the rectifier tube to be closed;
under the condition that the first voltage is less than 0 and the second voltage is not less than 0, controlling a rectifier tube corresponding to the first comparator to be conducted;
and under the condition that the first voltage is not less than 0 and the second voltage is less than 0, controlling the rectifier tube corresponding to the second comparator to be conducted.
CN202111171931.4A 2021-10-08 2021-10-08 Self-driving circuit applied to resonant circuit LLC and LLC Pending CN113890373A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202111171931.4A CN113890373A (en) 2021-10-08 2021-10-08 Self-driving circuit applied to resonant circuit LLC and LLC

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202111171931.4A CN113890373A (en) 2021-10-08 2021-10-08 Self-driving circuit applied to resonant circuit LLC and LLC

Publications (1)

Publication Number Publication Date
CN113890373A true CN113890373A (en) 2022-01-04

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Application Number Title Priority Date Filing Date
CN202111171931.4A Pending CN113890373A (en) 2021-10-08 2021-10-08 Self-driving circuit applied to resonant circuit LLC and LLC

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