Flyback topology circuit and circuit board

Abstract

The embodiment of the invention discloses a flyback topology circuit and a circuit board, and relates to the field of power circuits. The flyback topology circuit provided by the invention comprises a resonant conversion LLC module, a first rectification filtering module, a first load module, a switching module, a flyback module, a second rectification filtering module, a voltage regulation module and a second load module. Based on the circuit structure provided by the invention, when the voltage value of the first working voltage is greater than the voltage value of the second working voltage, the switching module is switched on to enable the second load module to work based on the first working voltage, or when the voltage value of the first working voltage is smaller than or equal to the voltage value of the second working voltage, the switching module is switched off to enable the second load module to work based on the second working voltage. And the second load module works based on the second working voltage. According to the embodiment of the invention, the power conversion efficiency of the flyback topology circuit can be improved, and the flyback topology circuit is simple in structure.

Description

Technical Field

[0001] This application relates to the field of flyback topology circuits, and more particularly to a flyback topology circuit and circuit board. Background Technology

[0002] In flyback topologies with auxiliary power supply output, to meet standards such as 80 Plus Titanium, a control chip capable of switching between three operating modes—QR (Quasi-Resonant), CCM (Continuous Conduction Mode), and DCM (Discontinuous Conduction Mode)—is often used. Through this control chip, the flyback topology can flexibly select the most suitable operating mode under different load conditions, thereby optimizing efficiency.

[0003] Synchronous rectification technology is widely used in the auxiliary output section of flyback topologies. Furthermore, the design of the flyback transformer is meticulously optimized to further improve efficiency. The design of the flyback transformer directly affects the conversion efficiency of the power input to the flyback topology; through reasonable winding design, material selection, and optimized magnetic circuit layout, the conversion efficiency can be improved to a certain extent.

[0004] However, while these methods have achieved some success in improving the power conversion efficiency of circuits, the overall circuit often becomes more complex due to the topological limitations of flyback topologies, which translates to more external components and higher costs. Furthermore, due to the limitations of flyback topologies, the power conversion efficiency often only reaches around 90%, making further improvements difficult. Summary of the Invention

[0005] This application provides a flyback topology circuit and circuit board, which can improve the power conversion efficiency of the flyback topology circuit, and the structure of the flyback topology circuit is simple. The technical solution is as follows:

[0006] In a first aspect, embodiments of this application provide a flyback topology circuit, the flyback topology circuit comprising:

[0007] The resonant converter LLC module, the first rectifier and filter module, the first load module, the switching module, the flyback module, the second rectifier and filter module, the voltage regulation module, and the second load module are included.

[0008] The first output terminal of the LLC module is electrically connected to the input terminal of the first rectifier and filter module. The LLC module converts the input voltage to obtain the first converted voltage and outputs the first converted voltage to the first rectifier and filter module.

[0009] The output terminal of the first rectifier and filter module is electrically connected to the input terminal of the first load module and the first terminal of the switching module, respectively. The first rectifier and filter module rectifies and filters the first conversion voltage to obtain the first operating voltage, and outputs the first operating voltage to the first load module so that the first load module operates based on the first operating voltage.

[0010] The first output terminal of the flyback module, the output terminal of the voltage regulation module, and the input terminal of the second rectifier and filter module are electrically connected. The flyback module converts the input voltage to obtain the second converted voltage, and the voltage regulation module adjusts the second converted voltage to obtain the adjusted voltage and outputs the adjusted voltage to the second rectifier and filter module.

[0011] The output terminal of the second rectifier and filter module is electrically connected to the input terminal of the second load module. The second rectifier and filter module rectifies and filters the adjustment voltage to obtain the second working voltage, and outputs the second working voltage to the second load module.

[0012] The second terminal of the switching module is electrically connected to the output terminal of the second rectifier and filter module. When the voltage value of the first working voltage is greater than the voltage value of the second working voltage, the switching module is turned on so that the second load module operates based on the first working voltage. Alternatively, when the voltage value of the first working voltage is less than or equal to the voltage value of the second working voltage, the switching module is turned off so that the second load module operates based on the second working voltage.

[0013] Secondly, embodiments of this application provide a circuit board, which includes the flyback topology circuit of the first aspect.

[0014] The beneficial effects of the technical solutions provided in some embodiments of this application include at least the following:

[0015] The flyback topology circuit provided in this application includes a main circuit and an auxiliary circuit. The main circuit includes an LLC module, a first rectifier-filter module, and a first load module. The auxiliary circuit includes a flyback module, a second rectifier-filter module, and a second load module. Addressing the low power conversion efficiency of the auxiliary circuit in the flyback topology, when the first operating voltage output by the first rectifier-filter module in the main circuit is greater than the second operating voltage output by the second rectifier-filter module in the auxiliary circuit, a switching module is activated to connect the second load module of the auxiliary circuit to the main circuit. This effectively converts the auxiliary circuit to utilize the LLC module and the first rectifier-filter module for power conversion, thereby improving the overall power conversion efficiency of the flyback topology circuit. Furthermore, when the first operating voltage output by the first rectifier-filter module in the main circuit is less than or equal to the second operating voltage output by the second rectifier-filter module in the auxiliary circuit, a switching module is deactivated to prevent the second operating voltage from the auxiliary circuit from flowing back into the main circuit and causing abnormal operation of the first load module. This improves the operational stability of the flyback topology circuit. Moreover, this flyback topology circuit has a simple circuit structure and low cost. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of a prior art flyback topology circuit provided in an embodiment of this application;

[0018] Figure 2 This is a schematic diagram of a flyback topology circuit provided in an embodiment of this application;

[0019] Figure 3 This is a schematic diagram of a flyback topology circuit provided in an embodiment of this application;

[0020] Figure 4 This is a schematic diagram of a flyback topology circuit provided in an embodiment of this application;

[0021] Figure 5 This is a schematic diagram of a flyback topology circuit provided in an embodiment of this application;

[0022] Figure 6 This is a schematic diagram of a flyback topology circuit provided in an embodiment of this application;

[0023] Figure 7This is a schematic diagram of a flyback topology circuit provided in an embodiment of this application;

[0024] Figure 8 This is a schematic diagram of a flyback topology circuit provided in an embodiment of this application;

[0025] Figure 9 This is a schematic diagram of a flyback topology circuit provided in an embodiment of this application. Detailed Implementation

[0026] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0027] In the description of this application, it should be understood that the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. In the description of this application, it should be noted that, unless otherwise expressly specified and limited, "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or devices. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances. Furthermore, in the description of this application, unless otherwise stated, "multiple" means two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist; for example, A and / or B can represent: A alone, A and B simultaneously, and B alone. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship.

[0028] The present application will now be described in detail with reference to specific embodiments.

[0029] In flyback topologies with auxiliary power supply output, to meet standards such as 80 Plus Titanium, a control chip capable of switching between three operating modes—QR (Quasi-Resonant), CCM (Continuous Conduction Mode), and DCM (Discontinuous Conduction Mode)—is often used. Through this control chip, the flyback topology can flexibly select the most suitable operating mode under different load conditions, thereby optimizing efficiency.

[0030] Synchronous rectification technology is widely used in the auxiliary output section of flyback topologies. Furthermore, the design of the flyback transformer is meticulously optimized to further improve efficiency. The design of the flyback transformer directly affects the conversion efficiency of the power input to the flyback topology; through reasonable winding design, material selection, and optimized magnetic circuit layout, the conversion efficiency can be improved to a certain extent.

[0031] Specifically, such as Figure 1 The diagram shown is a schematic representation of a prior art flyback topology circuit according to an embodiment of this application. It includes: an EMI (Electromagnetic Interference) module, a Power Factor Correction (PFC) module, a resonant converter LLC module, a first rectifier-filter module, a first load module, a switching module, a flyback module, a second rectifier-filter module, a voltage regulation module, and a second load module. The LLC module, the first rectifier-filter module, and the first load module serve as the main output circuit, while the flyback module, the second rectifier-filter module, and the second load module serve as auxiliary output circuits.

[0032] exist Figure 1 In the flyback topology circuit shown, the EMI module and the FPC module are electrically connected in sequence to receive AC or DC power. The EMI module filters the input voltage, and the FPC module performs power calibration on the input voltage.

[0033] Furthermore, this flyback topology circuit performs power conversion processing on the input voltage through an LLC module and a flyback module. A first rectifier filter module and a second rectifier filter module respectively rectify and filter the first converted voltage output from the LLC module and the second converted voltage output from the flyback module to obtain a first operating voltage and a second operating voltage as two output voltages. The first operating voltage is used as the operating voltage for the first load module, and the second operating voltage is used as the operating voltage for the second load module.

[0034] Since the main output circuit in the flyback topology circuit includes an LLC module and a first rectifier and filter module, digital soft-switching technology can be used to control the switching transistors in the LLC module to turn on and the rectifier transistors in the first rectifier and filter module to turn off, resulting in high power conversion efficiency of the main output circuit.

[0035] In the auxiliary output circuit, due to the use of a flyback topology, the power conversion efficiency of the second rectifier and filter module is low, regardless of whether it uses traditional diode rectification or synchronous rectification. Furthermore, additional synchronous rectification chips and peripheral components are required, leading to increased circuit complexity and cost in the auxiliary output circuit.

[0036] To address the aforementioned problems, this application provides a flyback topology circuit.

[0037] In one embodiment, such as Figure 2 The diagram shown is a schematic diagram of a flyback topology circuit provided in an embodiment of this application. The flyback topology circuit includes: a resonant converter LLC module 101, a first rectifier and filter module 102, a first load module 103, a switching module 104, a flyback module 105, a second rectifier and filter module 106, a voltage regulation module 107, and a second load module 108.

[0038] The first output terminal of LLC module 101 is electrically connected to the input terminal of the first rectifier and filter module 102. LLC module 101 converts the input voltage V0 to obtain a first converted voltage and outputs the first converted voltage to the first rectifier and filter module 102. The working principle of LLC module is to achieve voltage conversion by controlling the resonant frequency. Its advantages are that it achieves zero-voltage turn-on (ZVS) of the two primary-side switches and zero-current turn-off (ZCS) of the secondary-side rectifier. Through digital soft-switching technology, it can reduce the switching losses of the power supply and improve the efficiency and power density of the power converter.

[0039] The output terminal of the first rectifier and filter module 102 is electrically connected to the input terminal of the first load module 103 and the first terminal of the switching module 104, respectively. The first rectifier and filter module 102 rectifies and filters the first conversion voltage to obtain the first operating voltage, and outputs the first operating voltage V1 to the first load module 103 so that the first load module 103 operates based on the first operating voltage V1. For example, the voltage value of the first operating voltage V1 is 12V, and the first load module 103 operates according to the 12V first operating voltage V1.

[0040] The first output terminal of the flyback module 105 and the output terminal of the voltage regulation module 107 are electrically connected to the input terminal of the second rectifier and filter module 106. The flyback module 105 converts the input voltage to obtain a second converted voltage, and the voltage regulation module 107 adjusts the second converted voltage to obtain an adjusted voltage, and outputs the adjusted voltage to the second rectifier and filter module 106. The input voltage received by the flyback module 105 is the same as the input voltage received by the LLC module 101. The flyback topology, also known as the Flyback power supply topology, is a switching power supply topology.

[0041] The output terminal of the second rectifier and filter module 106 is electrically connected to the input terminal of the second load module 108. The second rectifier and filter module 106 rectifies and filters the adjustment voltage to obtain the second working voltage V2, and outputs the second working voltage V2 to the second load module 108.

[0042] The second terminal of the switching module 104 is electrically connected to the output terminal of the second rectifier-filter module 106. The switching module 104 is turned on when the voltage value of the first operating voltage V1 is greater than the voltage value of the second operating voltage V2, so that the second load module 108 operates based on the first operating voltage V1. For example, when the voltage value of the first operating voltage V1 is 12V and the voltage value of the second operating voltage V2 is less than 12V, the switching module 104 is turned on, and the second load module 108 is connected to the output circuit of the LLC module 101 and the first rectifier-filter module 102. At this time, both the first load module 103 and the second load module 108 of the flyback topology circuit use the LLC module 101 for power conversion. Compared with the conventional technology where the second load module 108 is rectified by the flyback module 105, the second load module 108 connected to the LLC module 101 uses the LLC module 101, which has a higher power conversion efficiency, for voltage conversion. Therefore, by connecting the second load module 108 to the output circuit of the LLC module 101 and the first rectifier and filter module 102 through the switching module 104, the power conversion efficiency of the flyback topology circuit can be effectively improved.

[0043] The switching module 104 is turned off when the voltage value of the first operating voltage V1 is less than or equal to the voltage value of the second operating voltage V2, so that the second load module 108 operates based on the second operating voltage V2. The voltage regulation module 107 adjusts the voltage value of the second conversion voltage output by the flyback module 105, thereby adjusting the voltage value of the second operating voltage V2, ensuring that the voltage value of the second operating voltage V2 is always less than the voltage value of the first operating voltage V1, thus ensuring that the second load module 108 is connected to the output circuit of the LLC module 101 and the first rectifier-filter module 102. For example, the voltage regulation module 107 adjusts the voltage value of the second conversion voltage by adjusting the duty cycle of the second conversion voltage through a digital signal, which is equivalent to adding a variable voltage source to the output circuit of the flyback module 105 and the second rectifier-filter module 106.

[0044] When the voltage value of the first operating voltage V1 is less than or equal to the voltage value of the second operating voltage V2, for example when the flyback topology circuit triggers the overcurrent protection OVP, the switching module 104 is turned off and stops working, so as to prevent the second operating voltage V2 from flowing back into the output circuit of LLC module 101 and the first rectifier and filter module 102, which would cause damage to components such as the first load module 101.

[0045] The flyback topology circuit provided in this application includes a main circuit and an auxiliary circuit. The main circuit includes an LLC module, a first rectifier-filter module, and a first load module. The auxiliary circuit includes a flyback module, a second rectifier-filter module, and a second load module. Addressing the low power conversion efficiency of the auxiliary circuit in the flyback topology, when the first operating voltage output by the first rectifier-filter module in the main circuit is greater than the second operating voltage output by the second rectifier-filter module in the auxiliary circuit, a switching module connects the second load module to the main circuit. This effectively converts the auxiliary circuit to utilize the LLC module and the first rectifier-filter module for power conversion, thereby improving the overall power conversion efficiency of the flyback topology circuit. Furthermore, when the first operating voltage output by the first rectifier-filter module in the main circuit is less than or equal to the second operating voltage output by the second rectifier-filter module in the auxiliary circuit, the switching module shuts off the second operating voltage to prevent backflow of the second operating voltage into the main circuit, which could cause malfunction of the first load module. This improves the operational stability of the flyback topology circuit. Moreover, this flyback topology circuit has a simple structure and low cost.

[0046] like Figure 3 The diagram shown is a schematic representation of a flyback topology circuit according to an embodiment of this application. The flyback topology circuit includes: an LLC module 201, a first rectifier-filter module 202, a first load module 203, a switching module 204, a flyback module 205, a second rectifier-filter module 206, a voltage regulation module 207, and a second load module 208. The connection structure of this flyback topology circuit is described above. Figure 2 This will not be elaborated upon here.

[0047] In this embodiment, the switching module includes 204: a first switching unit 2041, a second switching unit 2042, and a third switching unit 2043.

[0048] The first end of the third switching unit 2043 is connected to the output end of the second rectifier and filter module 206, the second end of the third switching unit 2043 is connected to the first end of the first switching unit 2041, and the second end of the first switching unit 2041 is connected to the output end of the first rectifier and filter module 202.

[0049] When the voltage value of the first operating voltage V1 is greater than the voltage value of the second operating voltage V2, the third switching unit 2043 switches to the first state, so that the first switching unit 2041 is turned on based on the third switching unit 2043 in the first state. Through the turned-on first switching unit 2041 and the third switching unit 2043 in the first state, the second load module 208 operates based on the first operating voltage V1. In other words, when the third switching unit 2043 is in the first state and the first switching unit 2041 is turned on, the switching module 204 is turned on, and the second load module 208 is connected to the output circuit of the LLC module 201 and the first rectifier and filter module 202.

[0050] The third terminal of the third switching unit 2043 is connected to the first terminal of the second switching unit 2042, and the second terminal of the second switching unit 2042 is connected to the third terminal of the first switching unit 2041. When the voltage value of the first operating voltage V1 is less than or equal to the voltage value of the second operating voltage V2, the third switching unit 2043 switches to the second state. Based on the second state of the third switching unit 2043, the second switching unit 2042 is turned on. Furthermore, the first switching unit 2041 is turned off based on the turned-on second switching unit 2042. Furthermore, through the turned-off first switching unit 2041, the second load module 208 operates based on the second operating voltage V2.

[0051] In other words, when the third switching unit 2043 is in the second state and the first switching unit 2041 is turned off, the switching module 204 is turned off to prevent the second operating voltage V2 from flowing back into the output circuits of the LLC module 201 and the first rectifier and filter module 202.

[0052] Specifically, such as Figure 4 The diagram shown is a schematic representation of a flyback topology circuit provided in an embodiment of this application. In this embodiment, the first switching unit 2041 includes a first MOSFET Q1 and a first resistor R1. The gate of the first MOSFET Q1 is connected to the first terminal of the first resistor R1 and the second terminal of the second switching unit 2042, respectively. The second terminal of the first resistor R1 is connected to the source of the first MOSFET Q1 and the output terminal of the first rectifier filter module 202, respectively. The drain of the first MOSFET Q1 is connected to the second terminal of the third switching unit.

[0053] The second switching unit 2042 includes a first transistor Q2. The emitter of the first transistor Q2 is connected to the third terminal of the first switching unit 2041, the collector of the first transistor Q2 is connected to the third terminal of the third switching unit 2043, and the base of the first transistor Q2 is connected to the second terminal of the third switching unit 2043.

[0054] The third switching unit 2043 includes: a switching unit Q3, a second resistor R2, a third resistor R3, a first diode D1, and a driving power supply V4. Figure 4 In this circuit, switching unit Q3 includes two transistors. The emitter and collector of one transistor in switching unit Q3 are connected to the collector of the other transistor in switching unit Q3 to ensure that the voltage drop of the two transistors in switching unit Q3 is the same. The second resistor R2 is the base bias resistor, and the third resistor R3 is the current limiting resistor.

[0055] The first collector of the switching unit Q3 is connected to the output terminal of the second rectifier and filter module 206. The first emitter of the switching unit Q3 is connected to the first end of the second resistor R2. The second emitter of the switching unit Q3 is connected to the second end of the second switching unit 2042. The second collector of the switching unit Q3 is connected to the first end of the third resistor R3 and the positive terminal of the first diode D1. The second end of the second resistor R2 is connected to the second end of the third resistor R3 and the driving power supply V4. The negative terminal of the first diode D1 is connected to the first end of the second switching module 2042.

[0056] based on Figure 4 The flyback topology circuit shown above operates as follows:

[0057] When the voltage value of the first working voltage V1 is greater than the voltage value of the second working voltage V2, the switching unit Q3 is turned off, that is, the third driving module 2043 is in the first state. The driving voltage of the driving power supply V4 is output to the first MOSFET Q1 through the third resistor R3 and the first diode D1. The driving voltage value of the driving power supply V4 is greater than the voltage value of the first working voltage V1. For example, the voltage value of the driving power supply V4 is 24V and the voltage value of the first working voltage V1 is 12V.

[0058] Based on the driving voltage of the driving power supply V4, the first MOSFET Q1 is turned on, which means the first switching module 2041 is turned on. When the third switching unit 2043 is in the first state and the first switching unit 2041 is turned on, the switching module 204 is turned on, and the second load module 208 is connected to the output circuit of the LLC module 201 and the first rectifier and filter module 202.

[0059] When the voltage value of the first working voltage V1 is less than or equal to the voltage value of the second working voltage V2, the switching unit Q3 is turned on, thereby turning on the first transistor Q2. The first MOSFET Q1 quickly approaches 0 based on the voltage drop Vgs of the turned-on first transistor Q2, and then the first MOSFET Q1 is turned off.

[0060] Based on the first MOSFET Q1 being turned off, that is, the first switching unit 2041 being turned off, the switching module 204 being turned off, the second operating voltage V2 is prevented from flowing back into the output circuits of LLC module 201 and the first rectifier and filter module 202, and the second load module 208 operates based on the second operating voltage V2.

[0061] The flyback topology circuit provided in this application includes a main circuit and an auxiliary circuit. The main circuit includes an LLC module, a first rectifier-filter module, and a first load module. The auxiliary circuit includes a flyback module, a second rectifier-filter module, and a second load module. Addressing the low power conversion efficiency of the auxiliary circuit in the flyback topology, when the first operating voltage output by the first rectifier-filter module in the main circuit is greater than the second operating voltage output by the second rectifier-filter module in the auxiliary circuit, a switching module is activated to connect the second load module of the auxiliary circuit to the main circuit. This effectively converts the auxiliary circuit to utilize the LLC module and the first rectifier-filter module for power conversion, thereby improving the overall power conversion efficiency of the flyback topology circuit. Furthermore, when the first operating voltage output by the first rectifier-filter module in the main circuit is less than or equal to the second operating voltage output by the second rectifier-filter module in the auxiliary circuit, a switching module is deactivated to prevent the second operating voltage from the auxiliary circuit from flowing back into the main circuit and causing abnormal operation of the first load module. This improves the operational stability of the flyback topology circuit. Moreover, this flyback topology circuit has a simple circuit structure and low cost.

[0062] like Figure 5 The diagram shown is a schematic representation of a flyback topology circuit according to an embodiment of this application. The flyback topology circuit includes: an LLC module 301, a first rectifier-filter module 302, a first load module 303, a switching module 304, a flyback module 305, a second rectifier-filter module 306, a voltage regulation module 307, and a second load module 308. The connection structure of this flyback topology circuit is described above. Figure 3 This will not be elaborated upon here.

[0063] In this embodiment, the switching module 304 includes a first switching unit 3041, a second switching unit 3042, a third switching unit 3043, and a driving voltage unit 3044.

[0064] The input terminal of the drive voltage unit 3044 is connected to the second output terminal of the LLC module 301 or the second output terminal of the flyback module 305. The output terminal of the drive voltage unit 3044 is connected to the third switching unit 3043. The drive voltage unit 3042 adjusts the first conversion voltage output by the LLC module 304 or the second conversion voltage output by the flyback module 305 to obtain the drive voltage, and outputs the drive voltage to the third switching unit 3043 so that when the third switching unit 3043 switches to the first state, the first switching unit 3041 is turned on based on the drive voltage.

[0065] For example, based on Figure 4 The provided structure includes a first switching unit 3041, a second switching unit 3042, and a third switching unit 3043, with the driving voltage unit 3044 acting as the driving power supply V4. When the voltage value of the first operating voltage V1 is greater than the voltage value of the second operating voltage V2, the switching unit Q3 is turned off, meaning the third driving module 3043 is in the first state. The driving voltage provided by the driving voltage unit 3044 is output to the first MOSFET Q1 through the third resistor R3 and the first diode D1, and the voltage value of the driving voltage of the driving voltage unit 3044 is greater than the voltage value of the first operating voltage V1.

[0066] Based on the driving voltage provided by the driving voltage unit 3044, the first MOSFET Q1 is turned on, which means the first switching module 3041 is turned on. When the third switching unit 3043 is in the first state and the first switching unit 3041 is turned on, the switching module 304 is turned on, and the second load module 308 is connected to the output circuit of the LLC module 301 and the first rectifier and filter module 302.

[0067] exist Figure 5 In the illustrated embodiment, the drive voltage unit 3044 is connected to the second output terminal of the LLC module 301. Specifically, as shown... Figure 6 The diagram shown is a schematic of a flyback topology circuit provided in this embodiment. The driving voltage unit 3044 includes: a second diode D2, a third diode D3, a first Zener diode D4, and a first capacitor C1.

[0068] The positive terminal of the second diode D2 is connected to the first output terminal of the LLC module 301, the positive terminal of the third diode D3 is connected to the second output terminal of the LLC module 301, the positive terminal of the first Zener diode D4 is connected to the third output terminal of the LLC module 301, the negative terminals of the second diode D2, the third diode D3, and the first Zener diode D4 are connected to the first terminal of the first capacitor C1 and the input terminal of the third switching unit 3043, respectively, and the second terminal of the first capacitor C1 is grounded.

[0069] In this embodiment, the structure of the driving voltage unit 3043 allows a driving voltage higher than the first operating voltage V1 to be provided to the third switching module 3043. Since the first switching unit 3041 requires a driving voltage higher than the first operating voltage V1, to avoid additional transformer windings generating driving voltage, and since the voltage output by the transformer included in the LLC module 301 is exactly twice the first operating voltage V1, the upper and lower arms of the transformer SR included in the LLC module 301 are rectified by the second diode D2 and the third diode D3, the first Zener diode D4 regulates the voltage, and the first capacitor C1 stores energy, thereby obtaining a stable driving voltage.

[0070] like Figure 6 The diagram shown is a schematic representation of a flyback topology circuit according to an embodiment of this application. The flyback topology circuit includes: an LLC module 401, a first rectifier-filter module 402, a first load module 403, a switching module 404, a flyback module 405, a second rectifier-filter module 406, a voltage regulation module 407, and a second load module 408. The connection structure of this flyback topology circuit is described above. Figure 3 This will not be elaborated upon here.

[0071] exist Figure 7 In the illustrated embodiment, the drive voltage unit 4043 is connected to the second output terminal of the flyback module 405. Specifically, as shown... Figure 8 The diagram shown is a schematic diagram of a flyback topology circuit provided in this embodiment. The flyback module 405 includes at least a first transformer T1 and a fourth diode D5, and the driving voltage unit 4044 includes a fifth diode D6 and a second capacitor C2.

[0072] The positive terminal of the fourth diode D5 is connected to the first output terminal of the first transformer T1, and the negative terminal of the fourth diode D5 is connected to the input terminal of the second rectifier filter module 406. The positive terminal of the fifth diode D6 is connected to the second output terminal of the first transformer T1, and the negative terminal of the fifth diode D6 is connected to the first terminal of the second capacitor C2 and the input terminal of the third switching unit 5043, respectively. The second terminal of the second capacitor C2 is connected to the negative terminal of the fifth diode D6.

[0073] In this embodiment, by adding a winding to the secondary side of the first transformer T1 included in the flyback module 405 and rectifying it with the fourth diode D6, a stable driving voltage with a voltage value higher than the first operating voltage V1 can also be obtained.

[0074] The flyback topology circuit provided in this application includes a main circuit and an auxiliary circuit. The main circuit includes an LLC module, a first rectifier-filter module, and a first load module. The auxiliary circuit includes a flyback module, a second rectifier-filter module, and a second load module. Addressing the low power conversion efficiency of the auxiliary circuit in the flyback topology, when the first operating voltage output by the first rectifier-filter module in the main circuit is greater than the second operating voltage output by the second rectifier-filter module in the auxiliary circuit, a switching module is activated to connect the second load module of the auxiliary circuit to the main circuit. This effectively converts the auxiliary circuit to utilize the LLC module and the first rectifier-filter module for power conversion, thereby improving the overall power conversion efficiency of the flyback topology circuit. Furthermore, when the first operating voltage output by the first rectifier-filter module in the main circuit is less than or equal to the second operating voltage output by the second rectifier-filter module in the auxiliary circuit, a switching module is deactivated to prevent the second operating voltage from the auxiliary circuit from flowing back into the main circuit and causing abnormal operation of the first load module. This improves the operational stability of the flyback topology circuit. Moreover, this flyback topology circuit has a simple circuit structure and low cost.

[0075] like Figure 9 The diagram shown is a schematic representation of a flyback topology circuit according to an embodiment of this application. The flyback topology circuit includes: an LLC module 501, a first rectifier-filter module 502, a first load module 503, a switching module 504, a flyback module 505, a second rectifier-filter module 506, a voltage regulation module 507, and a second load module 508. The connection structure of this flyback topology circuit is described above. Figure 2 For the structure of switching module 504, please refer to [link / reference]. Figure 4 The structure of the driving voltage unit is shown in [reference]. Figure 6 This will not be elaborated upon here.

[0076] The LLC module includes 501: fourth resistor R4, fifth resistor R5, sixth resistor R6, seventh resistor R7, eighth resistor R8, ninth resistor R9, tenth resistor R10, eleventh resistor R11, second transformer T2, second MOSFET Q4, third MOSFET Q5, fourth MOSFET Q6, fifth MOSFET Q7, third capacitor C3, and first inductor L1.

[0077] The first end of the fourth resistor R4 serves as the input terminal. The second end of the fourth resistor R4 is connected to the first end of the fifth resistor R5 and the gate of the second MOSFET Q4. The second end of the fifth resistor R5 is connected to the source of the second MOSFET Q4, the first end of the third capacitor C3, and the drain of the third MOSFET Q5. The drain of the second MOSFET Q4 receives the input voltage. The second end of the third capacitor C3 is connected to the first end of the first inductor L1. The second end of the first inductor L1 is connected to the input terminal of the second transformer T2.

[0078] The first end of the sixth resistor R6 is used as the input terminal. The second end of the sixth resistor R6 is connected to the first end of the seventh resistor R7 and the gate of the third MOSFET Q5. The second end of the seventh resistor R7 is connected to the source of the third MOSFET Q5 and then grounded.

[0079] The first end of the eighth resistor R8 is used as the input terminal. The second end of the eighth resistor R8 is connected to the first end of the ninth resistor R9 and the gate of the fourth MOSFET Q6. The drain of the fourth MOSFET Q6 is connected to the second output terminal of the second transformer T2. The second end of the ninth resistor R9 is connected to the source of the fourth MOSFET Q6 and then grounded.

[0080] The first end of the eleventh resistor R11 is used as the input terminal. The second end of the eleventh resistor R11 is connected to the first end of the tenth resistor R10 and the gate of the fifth MOSFET Q7. The drain of the fifth MOSFET Q7 is connected to the first output terminal of the second transformer T2. The second end of the tenth resistor R10 is connected to the source of the fifth MOSFET Q7 and then grounded.

[0081] The third output terminal of the second transformer T2 is connected to the input terminal of the first rectifier and filter module 502.

[0082] The first rectifier and filter module 502 includes: a twelfth resistor R12 and a first electrolytic capacitor EC1.

[0083] The first terminal of the first electrolytic capacitor EC1 is connected to the first output terminal of the LLC module 501, the first terminal of the twelfth resistor R12, and the output terminal of the first load module 503, respectively. The second terminal of the first electrolytic capacitor EC1 is connected to the second terminal of the twelfth resistor R12 and then grounded.

[0084] The flyback module 505 includes: a first transformer T1, a fourth diode D5, a sixth diode D7, a seventh diode D9, a second Zener diode D8, a third Zener diode D10, a fourth capacitor C4, a fifth capacitor C5, a flyback control chip, a thirteenth resistor R13, a fourteenth resistor R14, a fifteenth resistor R15, a sixteenth resistor R16, a seventeenth resistor R17, an optocoupler diode LA, and an optocoupler transistor LB.

[0085] The negative terminal of the sixth diode D7 receives the input voltage and is connected to the first input terminal of the first transformer T1. The positive terminal of the sixth diode D7 is connected to the positive terminal of the second Zener diode D8 and the first terminal of the fourth capacitor C4. The negative terminal of the second Zener diode D8 is connected to the first terminal of the flyback control chip and the second terminal of the fourth capacitor C4. The positive terminal of the seventh diode D9 is connected to the second input terminal of the first transformer T1. The negative terminal of the seventh diode D9 is connected to the first terminal of the fifth capacitor C5 and the second terminal of the flyback control chip. The second terminal of the fifth capacitor C5 is grounded. The positive terminal of the fourth diode D7 is connected to the output terminal of the first transformer T1. The negative terminal of the fourth diode D5 is connected to the first terminal of the thirteenth resistor R13 and the first terminal of the fifteenth resistor R15.

[0086] The second terminal of the thirteenth resistor R13 is connected to the first terminal of the fourteenth resistor R14 and the positive terminal of the optocoupler diode LA. The negative terminal of the optocoupler diode LA is connected to the negative terminal of the third Zener diode and the first terminal of the fourteenth resistor R14. The base of the third Zener diode D10 is connected to the second terminal of the fifteenth resistor R15 and the first terminal of the sixteenth resistor R16. The second terminal of the sixteenth resistor R16 is connected to the first terminal of the seventeenth resistor R17 and the output terminal of the voltage regulation module 507. The second terminal of the seventeenth resistor R17 is connected to the positive terminal of the third Zener diode D10 and then grounded.

[0087] The base of the optocoupler transistor LB is connected to the optocoupler diode LA. The collector of the optocoupler transistor LB is connected to the third terminal of the flyback control chip. The emitter of the optocoupler transistor LB is connected to the fourth terminal of the flyback control chip and then grounded.

[0088] The second rectifier and filter module 506 includes: a second electrolytic capacitor EC2 and an eighteenth resistor R18.

[0089] The first terminal of the second electrolytic capacitor EC2 is connected to the first output terminal of the flyback module 505, the first terminal of the eighteenth resistor R18, and the input terminal of the second load module 508, respectively. The second terminal of the second electrolytic capacitor EC2 is connected to the second terminal of the eighteenth resistor R18 and then grounded.

[0090] The voltage regulation module 507 includes: the nineteenth resistor R19, the twentieth resistor R20, the twenty-first resistor R21, the sixth capacitor C6, and the seventh capacitor C7.

[0091] The first end of the nineteenth resistor R19 is connected to the input end of the second rectifier filter module. The second end of the nineteenth resistor R19 is connected to the first end of the twentieth resistor R20 and the first end of the sixth capacitor C6. The second end of the twentieth resistor R20 is connected to the first end of the seventh capacitor C7 and the first end of the twenty-first resistor R21. The second end of the sixth capacitor C6 is connected to the second end of the seventh capacitor C7 and then grounded.

[0092] The flyback topology circuit provided in this application includes a main circuit and an auxiliary circuit. The main circuit includes an LLC module, a first rectifier-filter module, and a first load module. The auxiliary circuit includes a flyback module, a second rectifier-filter module, and a second load module. Addressing the low power conversion efficiency of the auxiliary circuit in the flyback topology, when the first operating voltage output by the first rectifier-filter module in the main circuit is greater than the second operating voltage output by the second rectifier-filter module in the auxiliary circuit, a switching module is activated to connect the second load module of the auxiliary circuit to the main circuit. This effectively converts the auxiliary circuit to utilize the LLC module and the first rectifier-filter module for power conversion, thereby improving the overall power conversion efficiency of the flyback topology circuit. Furthermore, when the first operating voltage output by the first rectifier-filter module in the main circuit is less than or equal to the second operating voltage output by the second rectifier-filter module in the auxiliary circuit, a switching module is deactivated to prevent the second operating voltage from the auxiliary circuit from flowing back into the main circuit and causing abnormal operation of the first load module. This improves the operational stability of the flyback topology circuit. Moreover, this flyback topology circuit has a simple circuit structure and low cost.

[0093] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0094] The above-disclosed embodiments are merely preferred embodiments of this application and should not be construed as limiting the scope of this application. Therefore, any equivalent variations made in accordance with the claims of this application are still within the scope of this application.

Claims

1. A flyback topology circuit, characterized in that, The flyback topology circuit includes: The resonant converter LLC module, the first rectifier and filter module, the first load module, the switching module, the flyback module, the second rectifier and filter module, the voltage regulation module, and the second load module are included. The first output terminal of the LLC module is electrically connected to the input terminal of the first rectifier and filter module. The LLC module converts the input voltage to obtain a first converted voltage and outputs the first converted voltage to the first rectifier and filter module. The output terminal of the first rectifier and filter module is electrically connected to the input terminal of the first load module and the first terminal of the switching module. The first rectifier and filter module rectifies and filters the first conversion voltage to obtain the first operating voltage, and outputs the first operating voltage to the first load module so that the first load module operates based on the first operating voltage. The first output terminal of the flyback module, the output terminal of the voltage regulation module, and the input terminal of the second rectifier and filter module are electrically connected. The flyback module converts the input voltage to obtain a second converted voltage, and the voltage regulation module adjusts the second converted voltage to obtain an adjusted voltage, and outputs the adjusted voltage to the second rectifier and filter module. The output terminal of the second rectifier and filter module is electrically connected to the input terminal of the second load module. The second rectifier and filter module rectifies and filters the adjustment voltage to obtain the second operating voltage, and outputs the second operating voltage to the second load module. The second terminal of the switching module is electrically connected to the output terminal of the second rectifier and filter module. When the voltage value of the first working voltage is greater than the voltage value of the second working voltage, the switching module is turned on so that the second load module operates based on the first working voltage. Alternatively, when the voltage value of the first working voltage is less than or equal to the voltage value of the second working voltage, the switching module is turned off so that the second load module operates based on the second working voltage.

2. The flyback topology circuit according to claim 1, characterized in that, The switching module includes: a first switching unit, a second switching unit, and a third switching unit; The first end of the third switching unit is connected to the output end of the second rectifier and filter module, the second end of the third switching unit is connected to the first end of the first switching unit, the second end of the first switching unit is connected to the output end of the first rectifier and filter module, the third end of the third switching unit is connected to the first end of the second switching unit, and the second end of the second switching unit is connected to the third end of the first switching unit. When the voltage value of the first working voltage is greater than the voltage value of the second working voltage, the third switching unit switches to the first state to turn on the first switching unit, and the second load module operates based on the first working voltage through the turned-on first switching unit and the third switching unit in the first state. Alternatively, when the voltage value of the first operating voltage is less than or equal to the voltage value of the second operating voltage, the third switching unit switches to the second state to turn on the second switching unit, and the first switching unit turns off based on the turned-on second switching unit, and through the turned-off first switching unit, the second load module operates based on the second operating voltage.

3. The flyback topology circuit according to claim 2, characterized in that, The first switching unit includes: a first MOSFET and a first resistor; The gate of the first MOS transistor is connected to the first end of the first resistor and the second end of the second switching unit, respectively. The second end of the first resistor is connected to the source of the first MOS transistor and the output of the first rectifier filter module, respectively. The drain of the first MOS transistor is connected to the second end of the third switching unit.

4. The flyback topology circuit according to claim 2, characterized in that, The second switching unit includes: a first transistor; The emitter of the first transistor is connected to the third terminal of the first switching unit, the collector of the first transistor is connected to the third terminal of the third switching unit, and the base of the first transistor is connected to the second terminal of the third switching unit.

5. The flyback topology circuit according to claim 2, characterized in that, The third switching unit includes: a switching unit, a second resistor, a third resistor, a first diode, and a driving power supply; The first collector of the switching unit is connected to the output terminal of the second rectifier filter module, the first emitter of the switching unit is connected to the first end of the second resistor, the second emitter of the switching unit is connected to the second end of the second switching unit, the second collector of the switching unit is connected to the first end of the third resistor and the positive terminal of the first diode, the second end of the second resistor is connected to the second end of the third resistor and the driving power supply, and the negative terminal of the first diode is connected to the first end of the second switching module.

6. The flyback topology circuit according to claim 2, characterized in that, The switching module further includes: a driving voltage unit; The input terminal of the driving voltage unit is connected to the second output terminal of the LLC module or the second output terminal of the flyback module, and the output terminal of the driving voltage unit is connected to the third switching unit. The driving voltage unit adjusts the first conversion voltage output by the LLC module or the second conversion voltage output by the flyback module to obtain the driving voltage, and outputs the driving voltage to the third switching unit so that when the third switching unit switches to the first state, the first switching unit is turned on based on the driving voltage.

7. The flyback topology circuit according to claim 6, characterized in that, The input terminal of the driving voltage unit is connected to the second output terminal of the LLC module; The driving voltage unit includes: a second diode, a third diode, a first Zener diode, and a first capacitor; The positive terminal of the second diode is connected to the second output terminal of the LLC module, the positive terminal of the third diode is connected to the second output terminal of the LLC module, the positive terminal of the first Zener diode is connected to the second output terminal of the LLC module, the negative terminals of the second diode, the third diode, and the first Zener diode are respectively connected to the first terminal of the first capacitor and the input terminal of the third switching unit, and the second terminal of the first capacitor is grounded.

8. The flyback topology circuit according to claim 6, characterized in that, The input terminal of the driving voltage unit is connected to the second output terminal of the flyback module; The flyback module includes at least a first transformer and a fourth diode, and the drive voltage unit includes a fifth diode and a second capacitor. The positive terminal of the fourth diode is connected to the first output terminal of the first transformer, the negative terminal of the fourth diode is connected to the input terminal of the second rectifier filter module, the positive terminal of the fifth diode is connected to the second output terminal of the first transformer, the negative terminal of the fifth diode is connected to the first terminal of the second capacitor and the input terminal of the third switching unit, and the second terminal of the second capacitor is connected to the negative terminal of the fifth diode.

9. The flyback topology circuit according to claim 1, characterized in that, The LLC module includes: a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a second transformer, a second MOSFET, a third MOSFET, a fourth MOSFET, a fifth MOSFET, a third capacitor, and a first inductor; The first end of the fourth resistor serves as the input terminal. The second end of the fourth resistor is connected to the first end of the fifth resistor and the gate of the second MOS transistor. The second end of the fifth resistor is connected to the source of the second MOS transistor, the first end of the third capacitor, and the drain of the third MOS transistor. The drain of the second MOS transistor receives the input voltage. The second end of the third capacitor is connected to the first end of the first inductor. The second end of the first inductor is connected to the input terminal of the second transformer. The first end of the sixth resistor serves as the input terminal, the second end of the sixth resistor is connected to the first end of the seventh resistor and the gate of the third MOS transistor, and the second end of the seventh resistor is connected to the source of the third MOS transistor and then grounded. The first end of the eighth resistor serves as the input terminal. The second end of the eighth resistor is connected to the first end of the ninth resistor and the gate of the fourth MOS transistor. The drain of the fourth MOS transistor is connected to the second output terminal of the second transformer. The second end of the ninth resistor is connected to the source of the fourth MOS transistor and then grounded. The first end of the eleventh resistor serves as the input terminal. The second end of the eleventh resistor is connected to the first end of the tenth resistor and the gate of the fifth MOS transistor. The drain of the fifth MOS transistor is connected to the first output terminal of the second transformer. The second end of the tenth resistor is connected to the source of the fifth MOS transistor and then grounded. The third output terminal of the second transformer is connected to the input terminal of the first rectifier and filter module.

10. The flyback topology circuit according to claim 1, characterized in that, The first rectifier and filter module includes: a twelfth resistor and a first electrolytic capacitor; The first terminal of the first electrolytic capacitor is connected to the output terminal of the LLC module, the first terminal of the twelfth resistor, and the output terminal of the first load module, respectively. The second terminal of the first electrolytic capacitor is connected to the second terminal of the twelfth resistor and then grounded.

11. The flyback topology circuit according to claim 1, characterized in that, The flyback module includes: a first transformer, a fourth diode, a sixth diode, a seventh diode, a second Zener diode, a third Zener diode, a fourth capacitor, a fifth capacitor, a flyback control chip, a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, a seventeenth resistor, an optocoupler diode, and an optocoupler transistor; The negative terminal of the sixth diode receives the input voltage and is connected to the first input terminal of the first transformer. The positive terminal of the sixth diode is connected to the positive terminal of the second Zener diode and the first terminal of the fourth capacitor. The negative terminal of the second Zener diode is connected to the first terminal of the flyback control chip and the second terminal of the fourth capacitor. The positive terminal of the seventh diode is connected to the second input terminal of the first transformer. The negative terminal of the seventh diode is connected to the first terminal of the fifth capacitor and the second terminal of the flyback control chip. The second terminal of the fifth capacitor is grounded. The positive terminal of the fourth diode is connected to the output terminal of the first transformer. The negative terminal of the fourth diode is connected to the first terminal of the thirteenth resistor and the first terminal of the fifteenth resistor. The second terminal of the thirteenth resistor is connected to the first terminal of the fourteenth resistor and the positive terminal of the optocoupler diode. The negative terminal of the optocoupler diode is connected to the negative terminal of the third Zener diode and the first terminal of the fourteenth resistor. The base of the third Zener diode is connected to the second terminal of the fifteenth resistor and the first terminal of the sixteenth resistor. The second terminal of the sixteenth resistor is connected to the first terminal of the seventeenth resistor and the output terminal of the voltage regulation module. The second terminal of the seventeenth resistor is connected to the positive terminal of the third Zener diode and then grounded. The base of the optocoupler transistor is connected to the optocoupler diode, the collector of the optocoupler transistor is connected to the third terminal of the flyback control chip, and the emitter of the optocoupler transistor is connected to the fourth terminal of the flyback control chip and then grounded.

12. The flyback topology circuit according to claim 1, characterized in that, The second rectifier and filter module includes: a second electrolytic capacitor and an eighteenth resistor; The first end of the second electrolytic capacitor is connected to the first output end of the flyback module, the first end of the eighteenth resistor, and the input end of the second load module, respectively. The second end of the second electrolytic capacitor is connected to the second end of the eighteenth resistor and then grounded.

13. The flyback topology circuit according to claim 1, characterized in that, The voltage regulation module includes: a nineteenth resistor, a twentieth resistor, a twenty-first resistor, a sixth capacitor, and a seventh capacitor; The first end of the nineteenth resistor is connected to the input end of the second rectifier filter module. The second end of the nineteenth resistor is connected to the first end of the twentieth resistor and the first end of the sixth capacitor. The second end of the twentieth resistor is connected to the first end of the seventh capacitor and the first end of the twentieth resistor. The second end of the sixth capacitor is connected to the second end of the seventh capacitor and then grounded.

14. A circuit board, characterized in that, The circuit board includes a flyback topology circuit as described in any one of claims 1-13.

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