Control circuit of resonant converter

Abstract

The embodiment of the utility model relates to a control circuit of a resonant converter. The circuit comprises the resonant converter, a feedback module, a control module and a driving module, output signals of the resonant converter are fed back to the control module through the feedback module, and the driving module is controlled to output different driving signals after internal adjustment of the control module, so that the resonant converter operates stably. Therefore, the technical effects of stable control of the resonant converter under different load working conditions and reduction of production material cost can be realized.

Description

Technical Field

[0001] Embodiments of the present application relate to the technical field of resonant circuits, and in particular, to a control circuit of a resonant converter. Background Art

[0002] As an isolated DC converter, the Inductor-Inductor-Capacitor (LLC) resonant converter uses a resonant circuit to implement soft switching technology, which helps to reduce the switching loss of the switch tube and improve the overall efficiency of the power supply.

[0003] The LLC resonant converter has higher energy conversion efficiency and higher circuit board power density; at the same time, the circuit has less electromagnetic interference and stronger electromagnetic compatibility. Therefore, it is widely used in the fields of inverters, power adapters, communication power supplies, etc. However, the existing LLC resonant converter has a complex control circuit. In light load mode, due to the limitations of the actual parameter design of the main circuit, even if the operating frequency is adjusted to the maximum value through the feedback loop, the output voltage cannot be stabilized, resulting in poor control effect. Utility Model Content

[0004] In view of this, in order to solve the technical problem of unstable voltage of the above-mentioned resonant converter in light load mode, an embodiment of the present application provides a control circuit of a resonant converter.

[0005] In a first aspect, an embodiment of the present application provides a control circuit of a resonant converter, comprising:

[0006] Resonant converter, feedback module, control module and drive module;

[0007] The first end of the resonant converter is connected to the external power supply output end, the second end is connected to the first end of the driving module, the third end is connected to the second end of the driving module, the fourth end is connected to the third end of the driving module, the fifth end is connected to the fourth end of the driving module, the sixth end is connected to the first end of the control module, and the seventh end is connected to the first end of the feedback module and the electrical signal output end;

[0008] The second end of the feedback module is connected to the second end of the control module, and the third end is connected to the third end of the control module;

[0009] The fourth end of the control module is connected to the fifth end of the driving module, and the fifth end is connected to the sixth end of the driving module.

[0010] In a possible implementation, the resonant converter includes: a half-bridge module and a resonant voltage stabilization module;

[0011] The first end of the half-bridge module is connected to the external power supply output end, the second end is connected to the first end of the resonant voltage stabilizing module, the third end is connected to the second end of the resonant voltage stabilizing module and the first end of the control module, the fourth end is connected to the first end of the driving module, the fifth end is connected to the second end of the driving module, the sixth end is connected to the third end of the driving module, and the seventh end is connected to the fourth end of the driving module;

[0012] The third end of the resonant voltage stabilization module is connected to the first end and the electrical signal output end of the feedback module.

[0013] In a possible implementation, the half-bridge module includes: a first transistor, a second transistor, a first capacitor and a first resistor;

[0014] The first end of the first transistor is connected to the first end of the driving module, the second end is connected to one end of the first capacitor and the external power supply output end, and the third end is connected to the second end of the driving module, the second end of the second transistor and the first end of the resonant voltage stabilization module;

[0015] The other end of the first capacitor, the third end of the second transistor, the fourth end of the driving module, and one end of the first resistor are connected to a first ground end;

[0016] The first terminal of the second transistor is connected to the third terminal of the driving module;

[0017] The other end of the first resistor is connected to the second end of the resonant voltage stabilization module and the first end of the control module.

[0018] In a possible implementation, the resonant voltage stabilization module includes: a resonant submodule and a voltage stabilization submodule;

[0019] The first end of the resonant submodule is connected to the second end of the half-bridge module, the second end is connected to the third end of the half-bridge module and the first end of the control module, the third end is connected to the first end of the voltage stabilizing submodule, the fourth end is connected to the second end of the voltage stabilizing submodule, and the fifth end is connected to the third end of the voltage stabilizing submodule;

[0020] The fourth end of the voltage stabilizing submodule is connected to the electrical signal output end and the first end of the feedback module.

[0021] In a possible implementation, the resonant submodule includes: a first inductor, a second inductor, a resonant capacitor, and a first transformer;

[0022] The voltage stabilizing submodule includes: a first diode, a second diode and a second capacitor;

[0023] One end of the first inductor is connected to the second end of the half-bridge module, and the other end is connected to one end of the second inductor and one end of the main winding of the first transformer;

[0024] The other end of the second inductor is connected to the other end of the main winding of the first transformer and one end of the resonant capacitor;

[0025] The other end of the resonant capacitor is connected to the third end of the half-bridge module and the first end of the control module;

[0026] One side of the first secondary winding of the first transformer is connected to the forward input terminal of the first diode, the other side of the first secondary winding is connected to the second ground terminal as one side of the second secondary winding of the first transformer and one end of the second capacitor, and the other side of the second secondary winding is connected to the forward input terminal of the second diode;

[0027] The reverse output end of the first diode is connected to the reverse output end of the second diode, the other end of the second capacitor, the electrical signal output end and the first end of the feedback module.

[0028] In a possible implementation, the feedback module includes: a detection unit and a feedback unit;

[0029] The first end of the detection unit is connected to the seventh end and the electrical signal output end of the resonant converter, the second end is connected to the first end of the feedback unit, and the third end and the second end of the feedback unit are connected to the third ground end;

[0030] The third terminal of the feedback unit is linked to the second terminal of the control module, and the fourth terminal is connected to the third terminal of the control module.

[0031] In a possible implementation, the detection unit includes: a second resistor and a third resistor;

[0032] One end of the second resistor is connected to the seventh end of the resonant converter and the electrical signal output end, and the other end is connected to the first end of the feedback unit and one end of the third resistor;

[0033] The other end of the third resistor and the second end of the feedback unit are connected to the third ground end.

[0034] In a possible implementation, the feedback unit includes: a fourth resistor, a fifth resistor, a voltage stabilization source, and an isolation optocoupler;

[0035] The first end of the voltage stabilizing source is connected to the second end of the detection unit, the second end and the third end of the detection unit are connected to the third grounding end, and the third end is connected to one end of the fifth resistor and one end of the secondary side of the isolation optocoupler;

[0036] The other end of the fifth resistor is connected to one end of the fourth resistor and the other end of the secondary side of the isolation optocoupler;

[0037] The other end of the fourth resistor is connected to the electrical signal output end;

[0038] One end of the primary side of the isolation optical coupler is connected to the second end of the control module, and the other end of the primary side is connected to the third end of the control module.

[0039] In a possible implementation manner, the control module includes: a control chip, a third capacitor, a sixth resistor, a seventh resistor, and an eighth resistor;

[0040] The first pin of the control chip is connected to the external power supply output terminal, the second pin is connected to the sixth terminal of the resonant converter, the third pin is connected to the fifth terminal of the driving module, the fourth pin is connected to the sixth terminal of the driving module, the fifth pin and one end of the third capacitor, one end of the sixth resistor, one end of the seventh resistor and the third end of the feedback module are connected to the fourth ground terminal, the sixth pin is connected to the other end of the third capacitor, the seventh pin is connected to the other end of the sixth resistor, and the eighth pin is connected to the other end of the seventh resistor and one end of the eighth resistor;

[0041] The other end of the eighth resistor is connected to the second end of the feedback module.

[0042] In a possible implementation manner, the driving module includes: a driving chip, a fourth capacitor, a fifth capacitor, a second transformer, a ninth resistor, a tenth resistor, an eleventh resistor and a twelfth resistor;

[0043] The first pin of the driving chip is connected to the external power output terminal, the second pin is connected to one end of the fourth capacitor, the third pin is connected to one end of the fifth capacitor, the fourth pin is connected to the fourth ground terminal, the fifth pin is connected to the fifth end of the control module, and the sixth pin is connected to the fourth end of the control module;

[0044] The other end of the fourth capacitor is connected to one end of the primary coil of the second transformer;

[0045] The other end of the fifth capacitor is connected to the other end of the primary coil of the second transformer;

[0046] One end of the first secondary coil of the second transformer is connected to one end of the ninth resistor, the other end of the first secondary coil is connected to one end of the tenth resistor and the third end of the resonant converter, one end of the second secondary coil of the second transformer, one end of the twelfth resistor and the fifth end of the resonant converter are connected to the first ground terminal, and the other end of the second secondary coil is connected to one end of the eleventh resistor;

[0047] The other end of the ninth resistor is connected to the other end of the tenth resistor and the second end of the resonant converter, and the other end of the eleventh resistor is connected to the other end of the twelfth resistor and the fourth end of the resonant converter.

[0048] The resonant circuit provided in the embodiment of the present application is provided with a resonant converter, a feedback module, a control module and a driving module; the first end of the resonant converter is connected to the external power supply output end, the second end is connected to the first end of the driving module, the third end is connected to the second end of the driving module, the fourth end is connected to the third end of the driving module, the fifth end is connected to the fourth end of the driving module, the sixth end is connected to the first end of the control module, and the seventh end is connected to the first end of the feedback module and the electric signal output end; the second end of the feedback module is connected to the second end of the control module, and the third end is connected to the third end of the control module; the fourth end of the control module is connected to the fifth end of the driving module, and the fifth end is connected to the sixth end of the driving module. The output signal of the resonant converter is fed back to the control module through the feedback module, and after the internal adjustment of the control module, the driving module is controlled to output different driving signals, so that the resonant converter operates stably. According to this scheme, the stable control of the resonant converter under different load conditions can be achieved, and the technical effect of reducing the production material cost can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0050] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0051] One or more embodiments are exemplarily described by pictures in the corresponding drawings, and these exemplified descriptions do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings represent similar elements, and unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

[0052] Figure 1 A schematic diagram of the structure of a control circuit of a resonant converter provided in an embodiment of the present application;

[0053] Figure 2 A schematic diagram of the structure of another control circuit of a resonant converter provided in an embodiment of the present application;

[0054] Figure 3 A schematic diagram of the structure of a control circuit of another resonant converter provided in an embodiment of the present application. DETAILED DESCRIPTION

[0055] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0056] The terms "including" and "having" in the embodiments of the present application are used to express an open-ended inclusive meaning, and mean that in addition to the listed elements / components / etc., there may be additional elements / components / etc.; the terms "first" and "second" etc. are used only as labels and are not intended to limit the quantity of their objects. In addition, the different elements and regions in the drawings are only schematically shown, so the present application is not limited to the sizes or distances shown in the drawings.

[0057] To facilitate understanding of the embodiments of the present application, further explanation will be given below with reference to specific embodiments in conjunction with the accompanying drawings. The embodiments do not constitute a limitation on the embodiments of the present application.

[0058] Figure 1 A schematic diagram of a control circuit of a resonant converter provided in an embodiment of the present application. Applicable in the control process of the resonant converter. Figure 1 The control circuit of the resonant converter specifically includes:

[0059] Resonant converter 10, feedback module 13, control module 14 and drive module 15;

[0060] The first end of the resonant converter 10 is connected to the output end of the external power supply Vin, the second end is connected to the first end of the driving module 15, the third end is connected to the second end of the driving module 15, the fourth end is connected to the third end of the driving module 15, the fifth end is connected to the fourth end of the driving module 15, the sixth end is connected to the first end of the control module 14, and the seventh end is connected to the first end of the feedback module 13 and the electrical signal output end Vout;

[0061] The second end of the feedback module 13 is connected to the second end of the control module 14, and the third end is connected to the third end of the control module 14;

[0062] The fourth end of the control module 14 is connected to the fifth end of the driving module 15 , and the fifth end is connected to the sixth end of the driving module 15 .

[0063] The resonant converter mentioned here is used to output a resonant signal. The feedback module mentioned here is used to analyze and judge the collected electrical signal to determine whether the output electrical signal meets the voltage requirement of the subsequent load circuit. The control module mentioned here is used to adjust the internal circuit control drive module to change the state after receiving the feedback information result when the output signal of the resonant voltage stabilization module is unstable, thereby achieving the purpose of adjusting the output signal of the resonant voltage stabilization module. The drive module mentioned here is used to drive the operating state of the half-bridge module after receiving the control instruction output by the control module.

[0064] according to Figure 1 The diagram provided shows that after the resonant converter 10 receives the input signal Vin, the internal path is opened, and a stable electrical signal is output after the resonant converter 10 is operated, and transmitted to the subsequent load circuit. When the feedback module 13 detects that the output electrical signal does not meet the stable voltage range, the abnormal signal information is fed back to the control module 14, and the control module 14 adjusts the state of the internal device and changes the output signal value, so that the connected drive module 15 changes the output signal, thereby achieving the purpose of adjusting the internal conduction state of the resonant converter 10. By adjusting, the electrical signal of the resonant converter 10 after the resonance processing and voltage stabilization processing is restored to the normal stable voltage range, thereby achieving the regulation effect.

[0065] The control circuit of the resonant converter provided in the embodiment of the present application is provided with a resonant converter, a feedback module, a control module and a driving module; the first end of the resonant converter is connected to the external power supply output end, the second end is connected to the first end of the driving module, the third end is connected to the second end of the driving module, the fourth end is connected to the third end of the driving module, the fifth end is connected to the fourth end of the driving module, the sixth end is connected to the first end of the control module, and the seventh end is connected to the first end of the feedback module and the electric signal output end; the second end of the feedback module is connected to the second end of the control module, and the third end is connected to the third end of the control module; the fourth end of the control module is connected to the fifth end of the driving module, and the fifth end is connected to the sixth end of the driving module. The output signal of the resonant converter is fed back to the control module through the feedback module, and after the internal adjustment of the control module, the driving module is controlled to output different driving signals, so that the resonant converter operates stably. By this scheme, the stable control of the resonant converter under different load conditions can be achieved, and the technical effect of reducing the production material cost can be achieved.

[0066] In a possible embodiment, the resonant converter includes: a half-bridge module and a resonant voltage stabilization module; the first end of the half-bridge module is connected to the external power supply output end, the second end is connected to the first end of the resonant voltage stabilization module, the third end is connected to the second end of the resonant voltage stabilization module and the first end of the control module, the fourth end is connected to the first end of the drive module, the fifth end is connected to the second end of the drive module, the sixth end is connected to the third end of the drive module, and the seventh end is connected to the fourth end of the drive module; the third end of the resonant voltage stabilization module is connected to the first end of the feedback module and the electrical signal output end.

[0067] In a possible embodiment, the half-bridge module includes: a first transistor, a second transistor, a first capacitor and a first resistor; the first end of the first transistor is connected to the first end of the driving module, the second end is connected to one end of the first capacitor and the external power supply output end, and the third end is connected to the second end of the driving module, the second end of the second transistor and the first end of the resonant voltage stabilization module; the other end of the first capacitor is connected to the third end of the second transistor, the fourth end of the driving module, and one end of the first resistor to the first ground terminal; the first end of the second transistor is connected to the third end of the driving module; the other end of the first resistor is connected to the second end of the resonant voltage stabilization module and the first end of the control module.

[0068] In a possible implementation, the resonant voltage stabilization module includes: a resonant submodule and a voltage stabilization submodule; the first end of the resonant submodule is connected to the second end of the half-bridge module, the second end is connected to the third end of the half-bridge module and the first end of the control module, the third end is connected to the first end of the voltage stabilization submodule, the fourth end is connected to the second end of the voltage stabilization submodule, and the fifth end is connected to the third end of the voltage stabilization submodule; the fourth end of the voltage stabilization submodule is connected to the electrical signal output end and the first end of the feedback module.

[0069] In a possible implementation, the resonant submodule includes: a first inductor, a second inductor, a resonant capacitor and a first transformer; the voltage stabilizing submodule includes: a first diode, a second diode and a second capacitor; one end of the first inductor is connected to the second end of the half-bridge module, and the other end is connected to one end of the second inductor and one end of the main winding of the first transformer; the other end of the second inductor is connected to the other end of the main winding of the first transformer and one end of the resonant capacitor; the other end of the resonant capacitor is connected to the third end of the half-bridge module and the first end of the control module; one side of the first secondary winding of the first transformer is connected to the forward input end of the first diode, the other side of the first secondary winding is connected to the second ground end as one side of the second secondary winding of the first transformer and one end of the second capacitor, and the other side of the second secondary winding is connected to the forward input end of the second diode; the reverse output end of the first diode is connected to the reverse output end of the second diode, the other end of the second capacitor, the electrical signal output end and the first end of the feedback module.

[0070] In a possible embodiment, the feedback module includes: a detection unit and a feedback unit; the first end of the detection unit is connected to the seventh end and the electrical signal output end of the resonant converter, the second end is connected to the first end of the feedback unit, and the third end and the second end of the feedback unit are connected to the third ground end; the third end of the feedback unit is linked to the second end of the control module, and the fourth end is connected to the third end of the control module.

[0071] In a possible embodiment, the detection unit includes: a second resistor and a third resistor; one end of the second resistor is connected to the seventh end and the electrical signal output end of the resonant converter, and the other end is connected to the first end of the feedback unit and one end of the third resistor; the other end of the third resistor is connected to the second end of the feedback unit to the third ground terminal.

[0072] In a possible embodiment, the feedback unit includes: a fourth resistor, a fifth resistor, a voltage regulator and an isolation optocoupler; the first end of the voltage regulator is connected to the second end of the detection unit, the second end and the third end of the detection unit are connected to the third ground terminal, the third end is connected to one end of the fifth resistor and one end of the secondary side of the isolation optocoupler; the other end of the fifth resistor is connected to one end of the fourth resistor and the other end of the secondary side of the isolation optocoupler; the other end of the fourth resistor is connected to the electrical signal output end; one end of the primary side of the isolation optocoupler is connected to the second end of the control module, and the other end of the primary side is connected to the third end of the control module.

[0073] In a possible implementation, the control module includes: a control chip, a third capacitor, a sixth resistor, a seventh resistor and an eighth resistor; the first pin of the control chip is connected to the external power supply output terminal, the second pin is connected to the sixth terminal of the resonant converter, the third pin is connected to the fifth terminal of the drive module, the fourth pin is connected to the sixth terminal of the drive module, the fifth pin and one end of the third capacitor, one end of the sixth resistor, one end of the seventh resistor and the third end of the feedback module are connected to the fourth ground terminal, the sixth pin is connected to the other end of the third capacitor, the seventh pin is connected to the other end of the sixth resistor, the eighth pin is connected to the other end of the seventh resistor and one end of the eighth resistor; the other end of the eighth resistor is connected to the second end of the feedback module.

[0074] In a possible implementation, the driving module includes: a driving chip, a fourth capacitor, a fifth capacitor, a second transformer, a ninth resistor, a tenth resistor, an eleventh resistor, and a twelfth resistor;

[0075] A first pin of the driving chip is connected to an external power supply output terminal, a second pin is connected to one end of a fourth capacitor, a third pin is connected to one end of a fifth capacitor, a fourth pin is connected to a fourth ground terminal, a fifth pin is connected to a fifth end of the control module, and a sixth pin is connected to a fourth end of the control module; the other end of the fourth capacitor is connected to one end of a primary coil of a second transformer; the other end of the fifth capacitor is connected to the other end of the primary coil of the second transformer; one end of the first secondary coil of the second transformer is connected to one end of a ninth resistor, the other end of the first secondary coil is connected to one end of a tenth resistor and a third end of a resonant converter, one end of a second secondary coil of the second transformer, one end of a twelfth resistor and a fifth end of the resonant converter are connected to the first ground terminal, and the other end of the second secondary coil is connected to one end of an eleventh resistor; the other end of the ninth resistor is connected to the other end of the tenth resistor and a second end of the resonant converter, and the other end of the eleventh resistor is connected to the other end of the twelfth resistor and a fourth end of the resonant converter.

[0076] The following will introduce the resonant converter including: a half-bridge module and a resonant voltage stabilizing module, the resonant voltage stabilizing module including: a resonant submodule and a voltage stabilizing submodule, the feedback module including: a detection unit and a feedback unit, a control module and a driving module as an example. Figure 2 A schematic diagram of the structure of a control circuit of another resonant converter provided in an embodiment of the present application. Figure 2 The introduction is made on the basis of the previous embodiment.

[0077] according to Figure 2 The control circuit of the resonant converter specifically includes:

[0078] A resonant converter 10 , a feedback module 13 , a control module 14 and a driving module 15 .

[0079] according to Figure 2 In the provided diagram, a resonant converter 10 in a control circuit of the resonant converter includes: a half-bridge module 11 and a resonant voltage stabilization module 12 .

[0080] The first end of the half-bridge module 11 is connected to the output end of the external power supply Vin, the second end is connected to the first end of the resonant voltage stabilization module 12, the third end is connected to the second end of the resonant voltage stabilization module 12 and the first end of the control module 14, the fourth end is connected to the first end of the driving module 15, the fifth end is connected to the second end of the driving module 15, the sixth end is connected to the third end of the driving module 15, and the seventh end is connected to the fourth end of the driving module 15.

[0081] The third terminal of the resonant voltage stabilization module 12 is connected to the first terminal of the feedback module 13 and the electrical signal output terminal Vout.

[0082] The half-bridge module mentioned here is used to alternately output signals for controlling the resonant voltage stabilization module. The resonant voltage stabilization module mentioned here is used to perform the resonance process of the device according to the signal output state of the half-bridge module, and to further perform voltage stabilization processing on the electrical signal after the resonance processing.

[0083] Further, according to Figure 2 The diagram provided shows that after the half-bridge module 11 receives the input signal Vin, the internal path is opened to control the resonant voltage stabilization module 12 to work, and after the resonant voltage stabilization module 12 runs, a stable electrical signal is output and transmitted to the subsequent load circuit. When the feedback module 13 detects that the output electrical signal does not meet the stable voltage range, the abnormal signal information is fed back to the control module 14, and the control module 14 adjusts the state of the internal device and changes the output signal value, so that the connected drive module 15 changes the output signal, thereby achieving the purpose of adjusting the internal conduction state of the half-bridge module 11. By adjusting, the electrical signal of the resonant voltage stabilization module 12 after the resonance processing and voltage stabilization processing returns to the normal stable voltage range, thereby achieving the regulation effect.

[0084] according to Figure 2 According to the provided diagram, the resonant voltage stabilizing module 12 in the control circuit of the resonant converter includes: a resonant submodule 121 and a voltage stabilizing submodule 122 .

[0085] The first end of the resonant submodule 121 is connected to the second end of the half-bridge module 11, the second end is connected to the third end of the half-bridge module 11 and the first end of the control module 14, the third end is connected to the first end of the voltage stabilizing submodule 122, the fourth end is connected to the second end of the voltage stabilizing submodule 122, and the fifth end is connected to the third end of the voltage stabilizing submodule 122.

[0086] The fourth terminal of the voltage stabilizing submodule 122 is connected to the output terminal of the electric signal Vin and the first terminal of the feedback module 13 .

[0087] The resonant submodule mentioned here is used to process the function of the resonant circuit. The voltage stabilizing submodule mentioned here is used to stabilize the electrical signal output by the resonant submodule, so that the output electrical signal is more stable.

[0088] Furthermore, after the half-bridge module outputs the electrical signal, the electrical signal is subjected to resonant conversion processing by the resonant submodule to output a DC voltage, which is then stabilized by the voltage regulator module to further output a stable DC signal, thereby providing a stable voltage for the subsequent load circuit and providing a collected electrical signal for the feedback module.

[0089] according to Figure 2 According to the provided diagram, the feedback module 13 in the control circuit of the resonant converter includes: a detection unit 131 and a feedback unit 132 .

[0090] The first end of the detection unit 131 is connected to the seventh end of the resonant converter 10 and the output end of the electric signal Vin, the second end is connected to the first end of the feedback unit 132, and the third end and the second end of the feedback unit 132 are connected to the third ground end GND.

[0091] The third terminal of the feedback unit 132 is connected to the second terminal of the control module 14 , and the fourth terminal is connected to the third terminal of the control module 14 .

[0092] The detection unit mentioned here is used to collect and detect the DC signal output by the resonant voltage stabilization module. The feedback unit mentioned here is used to analyze the size of the collected DC signal and whether the feedback DC signal is within the stable voltage range.

[0093] Furthermore, the detection unit obtains the DC signal output by the resonant converter 10, detects the DC signal, obtains the size of the DC signal, and then inputs the DC signal to the feedback unit 132. The feedback unit 132 analyzes and amplifies the DC signal, determines whether the DC signal output by the current circuit is within a stable and normal range, and feeds back the analysis result to the control module 14, which controls the drive module 15 according to the feedback result. When the received feedback result indicates that the DC signal is abnormal, the control instruction is adjusted internally by the control module 14, and the control instruction to the drive module 15 is changed, so that the drive module 15 changes the drive strategy, thereby adjusting the inside of the resonant converter 10.

[0094] Another control circuit of a resonant converter provided in an embodiment of the present application, through the switching action of a half-bridge module, turns on the input electrical signal of the resonant submodule, performs energy conversion on the input electrical signal through the resonant submodule, outputs a DC signal, and outputs a stable DC signal after further voltage stabilization processing of the DC signal by a voltage stabilization submodule; a detection unit detects the size of the output DC signal in real time, and inputs the collected DC signal to a feedback unit for analysis; when the DC signal is abnormal, the abnormal electrical signal is fed back to the control module through the feedback unit, the working mode of the internal device is adjusted through the control module, the output control instruction is changed, and when the driving module receives the changed control instruction, the half-bridge module is controlled to change the switch state and the size of the input electrical signal, so that the electrical signal after passing through the resonant submodule and the voltage stabilization submodule reaches a stable normal range, thereby achieving stable control of the resonant converter under different load conditions and reducing the production material cost.

[0095] The following will take the half-bridge module including: a first transistor, a second transistor, a first capacitor and a first resistor, the resonant submodule including: a first inductor, a second inductor, a resonant capacitor and a first transformer, the voltage stabilizing submodule including: a first diode, a second diode and a second capacitor, the detection unit including: a second resistor and a third resistor, the feedback unit including: a fourth resistor, a fifth resistor, a voltage stabilizing source and an isolation optocoupler, the control module including: a control chip, a third capacitor, a sixth resistor, a seventh resistor and an eighth resistor, and the drive module including: a drive chip, a fourth capacitor, a fifth capacitor, a second transformer, a ninth resistor, a tenth resistor, an eleventh resistor and a twelfth resistor as an example for introduction. Figure 3 A schematic diagram of the structure of a control circuit of another resonant converter provided in an embodiment of the present application. Figure 3 The invention is introduced on the basis of the first embodiment. Figure 3 The control circuit of the resonant converter specifically includes:

[0096] A half-bridge module 11 , a resonator module 121 , a voltage stabilizing module 122 , a detection unit 131 , a feedback unit 132 , a control module 14 and a driving module 15 .

[0097] according to Figure 3 According to the provided diagram, the half-bridge module 11 in the control circuit of the resonant converter includes: a first transistor Q1, a second transistor Q2, a first capacitor C1 and a first resistor R1.

[0098] The first end of the first transistor Q1 is connected to the first end of the driving module 15, the second end is connected to one end of the first capacitor C1 and the output end of the external power supply Vin, and the third end is connected to the second end of the driving module 15, the second end of the second transistor Q2 and the first end of the resonant voltage stabilization module 12.

[0099] The other end of the first capacitor C1 , the third end of the second transistor Q2 , the fourth end of the driving module 15 , and one end of the first resistor R1 are connected to the first ground end COM.

[0100] A first terminal of the second transistor Q2 is connected to a third terminal of the driving module 15 .

[0101] The other end of the first resistor R1 is connected to the second end of the resonant voltage stabilization module 12 and the first end of the control module 14 .

[0102] The first transistor and the second transistor mentioned here are devices with switch functions, such as MOS transistors, IGBTs, triodes or insulated gate bipolar transistors, etc. This application uses MOS transistors for illustration.

[0103] The first end of the first transistor mentioned here is the gate of the MOS tube, the second end is the drain of the MOS tube, and the third end is the source of the MOS tube. Similarly, the first end of the second transistor mentioned here is the gate of the MOS tube, the second end is the drain of the MOS tube, and the third end is the source of the MOS tube.

[0104] according to Figure 3 The diagram provided shows that the first transistor Q1 and the second transistor Q2 are turned on and off by the driving signal, and both transistors are kept in the off state when not working; in normal operation, one transistor is kept on and the other transistor is kept off. Then the input DC voltage is converted into a square wave voltage to act on the resonant voltage stabilizing module 12 of the subsequent stage. At the same time, through the filtering effect of the first capacitor C1 and the first resistor R1 as the detection resistor, it is detected whether there is an overcurrent phenomenon in the branch of the resonant voltage stabilizing module 12.

[0105] according to Figure 3 As shown in the diagram provided, the resonant submodule 121 in the control circuit of the resonant converter includes: a first inductor Lr, a second inductor Lm, a resonant capacitor Cr and a first transformer T1.

[0106] The voltage stabilizing submodule 122 includes: a first diode D1 , a second diode D2 , and a second capacitor C2 .

[0107] One end of the first inductor Lr is connected to the second end of the half-bridge module 11 , and the other end is connected to one end of the second inductor Lm and one end of the main winding of the first transformer T1 .

[0108] The other end of the second inductor Lm is connected to the other end of the main winding of the first transformer T1 and one end of the resonant capacitor Cr.

[0109] The other end of the resonant capacitor Cr is connected to the third end of the half-bridge module 11 and the first end of the control module 14 .

[0110] One side of the first secondary winding of the first transformer T1 is connected to the forward input terminal of the first diode D1, the other side of the first secondary winding is connected to the second ground terminal GND as one side of the second secondary winding of the first transformer T1 and one end of the second capacitor C2, and the other side of the second secondary winding is connected to the forward input terminal of the second diode D2.

[0111] The reverse output end of the first diode D1 is connected to the reverse output end of the second diode D2 , the other end of the second capacitor C2 , the electrical signal output end Vout and the first end of the feedback module 13 .

[0112] The first inductor Lr and the second inductor Lm mentioned here are both resonant inductors, wherein the second inductor Lm is the excitation inductor of the high-frequency transformer. The LLC resonant structure is formed by the first inductor Lr, the second inductor Lm and the resonant capacitor Cr, and the input electrical signal is converted into energy, and the input DC voltage is converted into a square wave voltage to provide the first transformer T1 with starting energy, and the electrical signal after the voltage conversion through the first transformer is provided with the required energy for the voltage stabilizing submodule. The soft switching function of the half-bridge module 11 is realized by the resonant submodule 121, and the electrical signals on the input side and the output side are electrically isolated at the same time.

[0113] The first diode D1 and the second diode D2 mentioned here are high-frequency rectifier diodes. The second capacitor C2 mentioned here is a voltage stabilizing capacitor. Further, the electrical signal output by the resonant submodule 121 is rectified by the first diode D1 and the second diode D1, and the output is stabilized by the second capacitor C2, and finally a stable DC voltage is output through the voltage stabilizing submodule.

[0114] according to Figure 3 According to the provided diagram, the detection unit 131 in the control circuit of the resonant converter includes: a second resistor R2 and a third resistor R3.

[0115] One end of the second resistor R2 is connected to the seventh end of the resonant converter 10 and the electrical signal output end Vout, and the other end is connected to the first end of the feedback unit 132 and one end of the third resistor R3.

[0116] The other end of the third resistor R3 and the second end of the feedback unit 132 are connected to the third ground terminal GND.

[0117] The output voltage Vout is obtained through the output end, and the voltage is detected by the voltage dividing effect of the second resistor R2 and the third resistor R3 in the detection unit 131. The output voltage is sampled and detected, and the detected voltage is fed back to the feedback unit 132 for analysis to ensure real-time detection of whether the output signal of the resonant submodule 121 is within a normal range.

[0118] according to Figure 3 According to the provided diagram, the feedback unit 132 in the control circuit of the resonant converter includes: a fourth resistor R4, a fifth resistor R5, a voltage regulator U4 and an isolation optocoupler U3.

[0119] The first end of the voltage regulator U4 is connected to the second end of the detection unit 131, the second end and the third end of the detection unit 131 are connected to the third ground terminal GND, and the third end is connected to one end of the fifth resistor R5 and one end of the secondary side of the isolation optocoupler U3.

[0120] The other end of the fifth resistor R5 is connected to one end of the fourth resistor R4 and the other end of the secondary side of the isolation optical coupler U3 .

[0121] The other end of the fourth resistor R4 is connected to the output end of the electrical signal Vout.

[0122] One end of the primary side of the isolation optical coupler U3 is connected to the second end of the control module 14 , and the other end of the primary side is connected to the third end of the control module 14 .

[0123] The detected electrical signal is input into the isolation optocoupler U3 through the detection unit 131 for comparison and amplification. The electrical signal representing the resonant voltage stabilizing module is input into the TL431 voltage stabilizing source U4 through the current limiting effect of the fourth resistor and the fifth resistor. The electrical signal is fed back to the control module through the isolation effect of the TL431 voltage stabilizing source U4 to provide reference data for the control signal to adjust the internal structure.

[0124] according to Figure 3 According to the provided diagram, the control module 14 in the control circuit of the resonant converter includes: a control chip U1, a third capacitor C3, a sixth resistor R6, a seventh resistor R7 and an eighth resistor R8.

[0125] The first pin of the control chip U1 is connected to the output end of the external power supply VCC, the second pin is connected to the sixth end of the resonant converter 10, the third pin is connected to the fifth end of the driving module 15, the fourth pin is connected to the sixth end of the driving module 15, the fifth pin and one end of the third capacitor C3, one end of the sixth resistor R6, one end of the seventh resistor R7 and the third end of the feedback module 13 are connected to the fourth ground terminal COM, the sixth pin is connected to the other end of the third capacitor C3, the seventh pin is connected to the other end of the sixth resistor R6, and the eighth pin is connected to the other end of the seventh resistor R7 and one end of the eighth resistor R8.

[0126] The other end of the eighth resistor R8 is connected to the second end of the feedback module 13 .

[0127] according to Figure 3The diagram provided shows that the control chip in the control module 14 adjusts the switching frequency of the circuit operation according to the feedback signal, and controls the half-bridge module by outputting two isolated complementary drive signals through the driver chip and the driver module, thereby adjusting the working state of the resonant voltage stabilizing module and stabilizing the output voltage. Among them, the sixth resistor R6 is a dead zone configuration resistor to ensure the working state of the control chip U1. The seventh resistor R7 and the eighth resistor R8 are operating frequency configuration resistors. By adjusting the size of the eighth resistor R8, the control chip U1 enters the burst working mode after the operating frequency reaches the corresponding limit value, and the circuit intermittently sends a drive signal to the main circuit of the resonant voltage stabilizing module, so as to stabilize the output voltage and ensure the normal operation of the circuit. Through a pin of the control chip U1 connected to the resonant submodule, it plays a real-time detection of whether the resonant submodule has an overcurrent phenomenon, so as to realize the circuit protection function. At the same time, through the adjustment of the control chip U1, the output signal is input to the driver module, so that the driver module controls the switching state of the transistor in the half-bridge module according to the signal.

[0128] according to Figure 3 According to the provided diagram, the driving module 15 in the control circuit of the resonant converter includes: a driving chip U2, a fourth capacitor C4, a fifth capacitor C5, a second transformer T2, a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11 and a twelfth resistor R12.

[0129] The first pin of the driving chip U2 is connected to the output terminal of the external power supply VCC, the second pin is connected to one end of the fourth capacitor C4, the third pin is connected to one end of the fifth capacitor C5, the fourth pin is connected to the fourth ground terminal COM, the fifth pin is connected to the fifth end of the control module 14, and the sixth pin is connected to the fourth end of the control module 14.

[0130] The other end of the fourth capacitor C4 is connected to one end of the primary coil of the second transformer T2.

[0131] The other end of the fifth capacitor C5 is connected to the other end of the primary coil of the second transformer T2.

[0132] One end of the first secondary coil of the second transformer T2 is connected to one end of the ninth resistor R9, the other end of the first secondary coil is connected to one end of the tenth resistor R10 and the third end of the resonant converter 10, one end of the second secondary coil of the second transformer T2, one end of the twelfth resistor R12 and the fifth end of the resonant converter 10 are connected to the first ground terminal COM, and the other end of the second secondary coil is connected to one end of the eleventh resistor R11.

[0133] The other end of the ninth resistor R9 is connected to the other end of the tenth resistor R10 and the second end of the resonant converter 10 . The other end of the eleventh resistor R11 is connected to the other end of the twelfth resistor R12 and the fourth end of the resonant converter 10 .

[0134] The control module 14 adjusts the switching frequency of the circuit according to the feedback signal, and outputs two isolated and complementary drive signals through the driving chip U2 and the second transformer T2 as a pulse transformer to control the first transistor Q1 and the second transistor Q2 of the half-bridge module, thereby adjusting the working state of the main circuit and stabilizing the output voltage.

[0135] The driver chip U2 outputs two opposite driving signals, and the fourth capacitor C4 and the fifth capacitor C5, which are isolated from the DC, provide input signals for the second transformer T2 corresponding to the isolation pulse transformer. After voltage conversion, the driving signal is driven by the ninth resistor R9 and input to the first transistor Q1 corresponding to the upper half bridge in the half-bridge module 11 through the tenth resistor R10, and the other driving signal drives the conduction state of the second transistor Q2 corresponding to the lower half bridge through the eleventh resistor R11 and the twelfth resistor R12. In this way, the switching state of the first transistor Q1 and the second transistor Q2 in the half-bridge module 11 is driven by the driver chip U2.

[0136] according to Figure 3 The diagram provided shows that in a possible example scenario, the working modes of the circuit can be divided into two types according to the load conditions: in normal load mode, after the circuit enters a steady state, the control chip U1 outputs stable control signals A and B according to the conditioning signal generated by the feedback module, and amplifies and isolates them through the driver chip U2 and the pulse transformer T2, generating complementary switch control signals to control the opening and closing of the MOS tubes Q1 and Q2, so that the main circuit works normally, and is isolated through the resonant structure and the first transformer T1 corresponding to the high-frequency transformer, and at the same time, the energy is transferred to the secondary side of the first transformer T1 corresponding to the high-frequency transformer, and then full-wave rectification is performed through the high-frequency rectifier diodes D1 and D2 on the secondary side of the first transformer T1, and a stable voltage is output after capacitor filtering and voltage stabilization.

[0137] When the circuit is in light load or no-load mode, due to the limitations of the actual parameter design of the main circuit corresponding to the resonant voltage stabilization module, the output voltage cannot be stabilized even if the operating frequency is adjusted to the maximum value through the feedback loop; therefore, by adjusting the resistance value of the eighth resistor R8 in the control module, the control chip enters the burst working mode after the operating frequency reaches the corresponding limit value, and the driving module intermittently sends a driving signal to the first transistor and the second transistor in the half-bridge module to control the switching state of the transistor, so that the main circuit stabilizes the output voltage based on the driving signal to ensure the normal operation of the circuit.

[0138] The present application provides a control circuit of a resonant converter. The control circuit of the resonant converter is configured to open the input electrical signals of the first inductor and the second inductor through the switching action of the transistor in the half-bridge module, perform energy conversion on the input electrical signals through the resonant structure composed of the resonant capacitor, the first inductor and the second inductor, output a direct current signal, and output a stable direct current signal after further voltage stabilization processing of the direct current signal by the action of the rectifier diode and the voltage stabilizing capacitor; the resistor in the detection unit detects the voltage division size of the output direct current signal in real time, and inputs the collected direct current signal to the voltage stabilizing source in the feedback unit for analysis; when the direct current signal is abnormal, the abnormal electrical signal is fed back to the control module through the isolation optical coupler in the feedback unit; the size value of the internal eighth resistor is adjusted through the control module, the output control instruction is changed, and the size of the output signal of the second transformer is controlled when the driver chip receives the changed control instruction, and the switch state and the size of the input electrical signal are changed for the transistor in the half-bridge module, so that the electrical signal after passing through the resonant submodule and the voltage stabilizing submodule reaches a stable normal range, thereby realizing stable control of the resonant converter under different load conditions and reducing the production material cost.

[0139] The specific implementation methods described above further illustrate the purpose, technical solutions and beneficial effects of the present application in detail. It should be understood that the above description is only the specific implementation method of the present application and is not intended to limit the scope of protection of the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A control circuit for a resonant converter, characterized in that: include: Resonant converter, feedback module, control module and drive module; The first end of the resonant converter is connected to the external power supply output end, the second end is connected to the first end of the driving module, the third end is connected to the second end of the driving module, the fourth end is connected to the third end of the driving module, the fifth end is connected to the fourth end of the driving module, the sixth end is connected to the first end of the control module, and the seventh end is connected to the first end of the feedback module and the electrical signal output end; The second end of the feedback module is connected to the second end of the control module, and the third end is connected to the third end of the control module; The fourth end of the control module is connected to the fifth end of the driving module, and the fifth end is connected to the sixth end of the driving module.

2. The circuit according to claim 1, characterized in that The resonant converter comprises: a half-bridge module and a resonant voltage stabilization module; The first end of the half-bridge module is connected to the external power supply output end, the second end is connected to the first end of the resonant voltage stabilizing module, the third end is connected to the second end of the resonant voltage stabilizing module and the first end of the control module, the fourth end is connected to the first end of the driving module, the fifth end is connected to the second end of the driving module, the sixth end is connected to the third end of the driving module, and the seventh end is connected to the fourth end of the driving module; The third end of the resonant voltage stabilization module is connected to the first end and the electrical signal output end of the feedback module.

3. The circuit according to claim 2, characterized in that The half-bridge module includes: a first transistor, a second transistor, a first capacitor and a first resistor; The first end of the first transistor is connected to the first end of the driving module, the second end is connected to one end of the first capacitor and the external power supply output end, and the third end is connected to the second end of the driving module, the second end of the second transistor and the first end of the resonant voltage stabilization module; The other end of the first capacitor, the third end of the second transistor, the fourth end of the driving module, and one end of the first resistor are connected to a first ground end; The first terminal of the second transistor is connected to the third terminal of the driving module; The other end of the first resistor is connected to the second end of the resonant voltage stabilization module and the first end of the control module.

4. The circuit according to claim 2, characterized in that The resonant voltage stabilization module comprises: a resonant submodule and a voltage stabilization submodule; The first end of the resonant submodule is connected to the second end of the half-bridge module, the second end is connected to the third end of the half-bridge module and the first end of the control module, the third end is connected to the first end of the voltage stabilizing submodule, the fourth end is connected to the second end of the voltage stabilizing submodule, and the fifth end is connected to the third end of the voltage stabilizing submodule; The fourth end of the voltage stabilizing submodule is connected to the electrical signal output end and the first end of the feedback module.

5. The circuit according to claim 4, characterized in that The resonant submodule includes: a first inductor, a second inductor, a resonant capacitor and a first transformer; The voltage stabilizing submodule includes: a first diode, a second diode and a second capacitor; One end of the first inductor is connected to the second end of the half-bridge module, and the other end is connected to one end of the second inductor and one end of the main winding of the first transformer; The other end of the second inductor is connected to the other end of the main winding of the first transformer and one end of the resonant capacitor; The other end of the resonant capacitor is connected to the third end of the half-bridge module and the first end of the control module; One side of the first secondary winding of the first transformer is connected to the forward input terminal of the first diode, the other side of the first secondary winding is connected to the second ground terminal as one side of the second secondary winding of the first transformer and one end of the second capacitor, and the other side of the second secondary winding is connected to the forward input terminal of the second diode; The reverse output end of the first diode is connected to the reverse output end of the second diode, the other end of the second capacitor, the electrical signal output end and the first end of the feedback module.

6. The circuit according to claim 1, characterized in that The feedback module includes: a detection unit and a feedback unit; The first end of the detection unit is connected to the seventh end and the electrical signal output end of the resonant converter, the second end is connected to the first end of the feedback unit, and the third end and the second end of the feedback unit are connected to the third ground end; The third terminal of the feedback unit is linked to the second terminal of the control module, and the fourth terminal is connected to the third terminal of the control module.

7. The circuit according to claim 6, characterized in that The detection unit includes: a second resistor and a third resistor; One end of the second resistor is connected to the seventh end of the resonant converter and the electrical signal output end, and the other end is connected to the first end of the feedback unit and one end of the third resistor; The other end of the third resistor and the second end of the feedback unit are connected to the third ground end.

8. The circuit according to claim 6, characterized in that The feedback unit includes: a fourth resistor, a fifth resistor, a voltage stabilization source and an isolation optical coupler; The first end of the voltage stabilizing source is connected to the second end of the detection unit, the second end and the third end of the detection unit are connected to the third grounding end, and the third end is connected to one end of the fifth resistor and one end of the secondary side of the isolation optocoupler; The other end of the fifth resistor is connected to one end of the fourth resistor and the other end of the secondary side of the isolation optocoupler; The other end of the fourth resistor is connected to the electrical signal output end; One end of the primary side of the isolation optical coupler is connected to the second end of the control module, and the other end of the primary side is connected to the third end of the control module.

9. The circuit according to claim 1, characterized in that The control module includes: a control chip, a third capacitor, a sixth resistor, a seventh resistor and an eighth resistor; The first pin of the control chip is connected to the external power supply output terminal, the second pin is connected to the sixth terminal of the resonant converter, the third pin is connected to the fifth terminal of the driving module, the fourth pin is connected to the sixth terminal of the driving module, the fifth pin and one end of the third capacitor, one end of the sixth resistor, one end of the seventh resistor and the third end of the feedback module are connected to the fourth ground terminal, the sixth pin is connected to the other end of the third capacitor, the seventh pin is connected to the other end of the sixth resistor, and the eighth pin is connected to the other end of the seventh resistor and one end of the eighth resistor; The other end of the eighth resistor is connected to the second end of the feedback module.

10. The circuit according to claim 1, characterized in that The driving module includes: a driving chip, a fourth capacitor, a fifth capacitor, a second transformer, a ninth resistor, a tenth resistor, an eleventh resistor and a twelfth resistor; The first pin of the driving chip is connected to the external power output terminal, the second pin is connected to one end of the fourth capacitor, the third pin is connected to one end of the fifth capacitor, the fourth pin is connected to the fourth ground terminal, the fifth pin is connected to the fifth end of the control module, and the sixth pin is connected to the fourth end of the control module; The other end of the fourth capacitor is connected to one end of the primary coil of the second transformer; The other end of the fifth capacitor is connected to the other end of the primary coil of the second transformer; One end of the first secondary coil of the second transformer is connected to one end of the ninth resistor, the other end of the first secondary coil is connected to one end of the tenth resistor and the third end of the resonant converter, one end of the second secondary coil of the second transformer, one end of the twelfth resistor and the fifth end of the resonant converter are connected to the first ground terminal, and the other end of the second secondary coil is connected to one end of the eleventh resistor; The other end of the ninth resistor is connected to the other end of the tenth resistor and the second end of the resonant converter, and the other end of the eleventh resistor is connected to the other end of the twelfth resistor and the fourth end of the resonant converter.

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