Switching power supply circuit and electronic device

Abstract

The utility model provides a kind of switching power supply circuit and electronic equipment, the switching power supply circuit includes first voltage output end, second voltage output end, direct current voltage module, isolated direct current conversion module, energy storage module and short-circuit prevention module, short-circuit prevention module can be connected in series between the second output end of isolated direct current conversion module and the second end of energy storage module, when the two output ends of isolated direct current conversion module are short-circuited, short-circuit prevention module can prevent energy storage module from short-circuiting, thereby improve the technical problem that safety is lower due to short-circuiting of energy storage module.

Description

Technical Field

[0001] This utility model relates to the field of electronic circuit technology, specifically to switching power supply circuits and electronic equipment. Background Technology

[0002] Traditional switching power supplies typically employ a DC-DC conversion structure, using high-frequency switching devices (such as MOSFETs) to control energy transfer and achieve voltage conversion and stable output. Their basic working principle involves adjusting the duty cycle to control the output voltage and utilizing components such as inductors and capacitors for filtering and energy storage.

[0003] However, most traditional solutions do not include a dedicated short-circuit protection structure in the secondary output path. If the two output terminals of the isolation converter module are accidentally short-circuited, current will flow directly into the energy storage element, causing a short circuit and reducing the overall reliability and safety of the system. Utility Model Content

[0004] The present invention provides a switching power supply circuit and electronic device that can improve the technical problem of low safety caused by short circuits in energy storage modules.

[0005] In a first aspect, embodiments of the present invention provide a switching power supply circuit, which includes a first voltage output terminal, a second voltage output terminal, a DC voltage module, an isolated DC-DC converter module, an energy storage module, and a short-circuit protection module. The first terminal of the DC voltage module is connected to the first voltage output terminal; the first input terminal of the isolated DC-DC converter module is connected to both the first terminal and the first voltage output terminal of the DC voltage module, and the second input terminal of the isolated DC-DC converter module is connected to the second terminal of the DC voltage module; the first terminal of the energy storage module is connected to the second terminal of the DC voltage module, the second input terminal of the isolated DC-DC converter module, and the first output terminal of the isolated DC-DC converter module, and the second terminal of the energy storage module is connected to the second voltage output terminal; the first terminal of the short-circuit protection module is connected to the second output terminal of the isolated DC-DC converter module, and the second terminal of the short-circuit protection module is connected to the second terminal of the energy storage module and the second voltage output terminal, configured to prevent a short circuit in the energy storage module.

[0006] In one embodiment, the short-circuit protection module includes a first inductor, a first end of which is connected to the second output terminal of the isolated DC-DC converter module, and a second end of which is connected to the second terminal and the second voltage output terminal of the energy storage module.

[0007] In one embodiment, the energy storage module includes a first capacitor, a first terminal of which is connected to a second terminal of a DC voltage module, a second input terminal of an isolated DC-DC converter module, and a first output terminal of the isolated DC-DC converter module, and a second terminal of the first capacitor is connected to a second terminal of a first inductor and a second voltage output terminal.

[0008] In one embodiment, the DC voltage module includes a battery cell, the positive terminal of which is connected to a first terminal of a first capacitor, a second input terminal of an isolated DC-DC converter module, and a first output terminal of the isolated DC-DC converter module, and the negative terminal of which is connected to the first input terminal and the first voltage output terminal of the isolated DC-DC converter module.

[0009] In one embodiment, the isolated DC-DC converter module includes an inverter unit, a transformer, and a rectifier unit. The first input terminal of the inverter unit is connected to the first terminal and the first voltage output terminal of the DC voltage module, and the second input terminal of the inverter unit is connected to the second terminal of the DC voltage module and the first terminal of the energy storage module. The first terminal of the primary winding of the transformer is connected to the first output terminal of the inverter unit, and the second terminal of the primary winding of the transformer is connected to the second output terminal of the inverter unit. The first input terminal of the rectifier unit is connected to the first terminal of the secondary winding of the transformer, and the second input terminal of the rectifier unit is connected to the second terminal of the secondary winding of the transformer. The first output terminal of the rectifier unit is connected to the second input terminal of the inverter unit, the second terminal of the DC voltage module, and the first terminal of the energy storage module. The second output terminal of the rectifier unit is connected to the first terminal of the short-circuit protection module.

[0010] In one embodiment, the inverter unit includes a first transistor, a second transistor, a third transistor, and a fourth transistor. The first terminal of the first transistor is connected to the second terminal of the DC voltage module and the first terminal of the energy storage module. The first terminal of the second transistor is connected to the second terminal of the first transistor and the first terminal of the primary winding. The second terminal of the second transistor is connected to the first terminal of the DC voltage module and the first voltage output terminal. The first terminal of the third transistor is connected to the first terminal of the first transistor. The first terminal of the fourth transistor is connected to the second terminal of the third transistor and the second terminal of the primary winding. The second terminal of the fourth transistor is connected to the second terminal of the second transistor.

[0011] In one embodiment, the rectifier unit includes a fifth transistor, a sixth transistor, a seventh transistor, and an eighth transistor. The first terminal of the fifth transistor is connected to the first terminal of the short-circuit protection module. The first terminal of the sixth transistor is connected to the second terminal of the fifth transistor and the first terminal of the secondary winding. The second terminal of the sixth transistor is connected to the second input terminal of the inverter unit, the second terminal of the DC voltage module, and the first terminal of the energy storage module. The first terminal of the seventh transistor is connected to the first terminal of the fifth transistor. The first terminal of the eighth transistor is connected to the second terminal of the seventh transistor and the second terminal of the secondary winding. The second terminal of the eighth transistor is connected to the second terminal of the sixth transistor.

[0012] In one embodiment, the rectifier unit operates in asynchronous rectification mode.

[0013] In one embodiment, the duty cycle of the transistors in the inverter unit is less than 0.5, and the duty cycle of the transistors in the rectifier unit is greater than 0.5.

[0014] Secondly, embodiments of the present invention provide an electronic device that includes the aforementioned switching power supply circuit.

[0015] The beneficial effects of the embodiments of this utility model are as follows: In the embodiments of this utility model, by connecting a short-circuit protection module in series between the second output terminal of the isolated DC-DC converter module and the second terminal of the energy storage module, a short circuit can be prevented from occurring in the energy storage module when the two output terminals of the isolated DC-DC converter module are short-circuited, thereby improving the technical problem of low safety caused by short circuit in the energy storage module. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. 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 block diagram of a switching power supply circuit provided in an embodiment of this utility model; Figure 2 This is a circuit diagram of the short-circuit protection module provided in an embodiment of this utility model; Figure 3 This is a circuit diagram of the energy storage module provided in an embodiment of this utility model; Figure 4 This is a circuit diagram of a DC voltage module provided in an embodiment of this utility model; Figure 5 This is a circuit schematic diagram of an isolated DC-DC converter module provided in an embodiment of this utility model; Figure 6 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this utility model.

[0018] Explanation of reference numerals in the attached figures: 10. DC voltage module; BAT (Battery Actuator); Battery cell; 20. Isolated DC-DC converter module; 21. Inverter unit; Q1, first transistor; Q2, second transistor; Q3, third transistor; Q4, fourth transistor; T, transformer; L1, primary winding; L2, secondary winding; 22. Rectifier unit; Q5, fifth transistor; Q6, sixth transistor; Q7, seventh transistor; Q8, eighth transistor; 30. Energy storage module; C. First capacitor; 40. Short-circuit protection module; L. First inductor; 100. Switching power supply circuit; Vout-, first voltage output terminal; Vout+, second voltage output terminal; 200. Electronic equipment. Detailed Implementation

[0019] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present utility model. In addition, it should be understood that the specific embodiments described herein are only for illustration and explanation of the present utility model and are not intended to limit the present utility model. In the present utility model, unless otherwise stated, directional terms such as "upper" and "lower" generally refer to the upper and lower positions of the device in actual use or operation, specifically the drawing directions in the accompanying drawings; while "inner" and "outer" refer to the outline of the device.

[0020] like Figure 1 As shown, an embodiment of this utility model provides a switching power supply circuit 100, which includes a first voltage output terminal Vout-, a second voltage output terminal Vout+, a DC voltage module 10, an isolated DC-DC converter module 20, an energy storage module 30, and a short-circuit protection module 40. The first terminal of the DC voltage module 10 is connected to the first voltage output terminal Vout-; the first input terminal of the isolated DC-DC converter module 20 is connected to the first terminal and the first voltage output terminal Vout- of the DC voltage module 10, and the second input terminal of the isolated DC-DC converter module 20 is connected to the second terminal of the DC voltage module 10; the first terminal of the energy storage module 30 is connected to the second terminal of the DC voltage module 10, the second input terminal of the isolated DC-DC converter module 20, and the first output terminal of the isolated DC-DC converter module 20, and the second terminal of the energy storage module 30 is connected to the second voltage output terminal Vout+; the first terminal of the short-circuit protection module 40 is connected to the second output terminal of the isolated DC-DC converter module 20, and the second terminal of the short-circuit protection module 40 is connected to the second terminal of the energy storage module 30 and the second voltage output terminal Vout+, and is configured to prevent short circuits in the energy storage module 30.

[0021] It is understood that the switching power supply circuit 100 provided in this embodiment, by connecting a short-circuit protection module 40 in series between the second output terminal of the isolated DC-DC converter module 20 and the second terminal of the energy storage module 30, can prevent the energy storage module 30 from short-circuiting when the two output terminals of the isolated DC-DC converter module 20 are short-circuited, thereby improving the technical problem of low safety caused by short circuit in the energy storage module 30.

[0022] It should be noted that the voltage at the second voltage output terminal Vout+ minus the voltage at the first voltage output terminal Vout- equals the output voltage Vout of the switching power supply circuit 100. The DC voltage module 10 provides a DC power supply voltage, Vbat. The isolated DC-DC converter module 20 converts the power supply voltage into a first DC voltage, and then converts it into a second DC voltage via the short-circuit protection module 40. The second DC voltage generates a compensation voltage, ΔV, through the energy storage module 30. Since the DC voltage module 10 and the energy storage module 30 are connected in series between the first voltage output terminal Vout- and the second voltage output terminal Vout+, Vout = Vbat + ΔV.

[0023] In one embodiment, such as Figure 2 As shown, the short-circuit protection module 40 includes a first inductor L, the first end of the first inductor L is connected to the second output terminal of the isolation DC-DC converter module 20, and the second end of the first inductor L is connected to the second terminal of the energy storage module 30 and the second voltage output terminal Vout+.

[0024] It should be noted that the short-circuit protection module 40 may be, but is not limited to, the first inductor L. In other embodiments, it may also be an electronic device that can prevent short circuits, such as a resistor or a diode. The first inductor L can be used to prevent the energy storage module 30 from short-circuiting when the two output terminals of the isolated DC-DC converter module 20 are short-circuited, thereby improving the safety of the switching power supply circuit 100.

[0025] In one embodiment, such as Figure 3 As shown, the energy storage module 30 includes a first capacitor C. The first end of the first capacitor C is connected to the second end of the DC voltage module 10, the second input end of the isolated DC-DC converter module 20, and the first output end of the isolated DC-DC converter module 20. The second end of the first capacitor C is connected to the second end of the first inductor L and the second voltage output end Vout+.

[0026] It should be noted that the energy storage module 30 can be, but is not limited to, the first capacitor C. In other embodiments, it can also be an electronic device such as an inductor that performs energy storage. When the energy storage module 30 is the first capacitor C, the first capacitor C can form an LC filter with the first inductor L to remove noise and suppress interference, thereby improving the stability of Vout.

[0027] In one embodiment, such as Figure 4 As shown, the DC voltage module 10 includes a battery unit BAT. The positive terminal of the battery unit BAT is connected to the first terminal of the first capacitor C, the second input terminal of the isolated DC-DC converter module 20, and the first output terminal of the isolated DC-DC converter module 20. The negative terminal of the battery unit BAT is connected to the first input terminal and the first voltage output terminal Vout- of the isolated DC-DC converter module 20.

[0028] It should be noted that the DC voltage module 10 may be, but is not limited to, a battery cell (BAT), and in other embodiments, other DC power sources may also be used. The battery cell (BAT) may be a single battery cell or multiple battery cells connected in series and / or parallel, or it may be one or more battery packs.

[0029] In one embodiment, such as Figure 5 As shown, the isolated DC-DC converter module 20 includes an inverter unit 21, a transformer T, and a rectifier unit 22. The first input terminal of the inverter unit 21 is connected to the first terminal and the first voltage output terminal Vout- of the DC voltage module 10, and the second input terminal of the inverter unit 21 is connected to the second terminal of the DC voltage module 10 and the first terminal of the energy storage module 30. The first terminal of the primary winding L1 of the transformer T is connected to the first output terminal of the inverter unit 21, and the second terminal of the primary winding L1 of the transformer T is connected to the second output terminal of the inverter unit 21. The first input terminal of the rectifier unit 22 is connected to the first terminal of the secondary winding L2 of the transformer T, and the second input terminal of the rectifier unit 22 is connected to the second terminal of the secondary winding L2 of the transformer T. The first output terminal of the rectifier unit 22 is connected to the second input terminal of the inverter unit 21, the second terminal of the DC voltage module 10, and the first terminal of the energy storage module 30. The second output terminal of the rectifier unit 22 is connected to the first terminal of the short-circuit protection module 40.

[0030] It should be noted that the inverter unit 21 can invert Vbat into the first AC power, which is then transformed by the transformer T to generate the second AC power. The rectifier unit 22 rectifies the second AC power to generate and output the first DC voltage, which is applied to the first inductor L and the first capacitor C connected in series. This not only generates a compensation voltage across the first capacitor C, but also serves to prevent short circuits and filter the circuit.

[0031] In one embodiment, such as Figure 5 As shown, the inverter unit 21 includes a first transistor Q1, a second transistor Q2, a third transistor Q3, and a fourth transistor Q4. The first terminal of the first transistor Q1 is connected to the second terminal of the DC voltage module 10 and the first terminal of the energy storage module 30. The first terminal of the second transistor Q2 is connected to the second terminal of the first transistor Q1 and the first terminal of the primary winding L1. The second terminal of the second transistor Q2 is connected to the first terminal of the DC voltage module 10 and the first voltage output terminal Vout-. The first terminal of the third transistor Q3 is connected to the first terminal of the first transistor Q1. The first terminal of the fourth transistor Q4 is connected to the second terminal of the third transistor Q3 and the second terminal of the primary winding L1. The second terminal of the fourth transistor Q4 is connected to the second terminal of the second transistor Q2.

[0032] It should be noted that at least one of the first transistor Q1, the second transistor Q2, the third transistor Q3, and the fourth transistor Q4 can be a field-effect transistor (MOS).

[0033] The first transistor Q1 switches synchronously with the fourth transistor Q4, and the second transistor Q2 switches synchronously with the third transistor Q3. The duty cycle of the first transistor Q1 is the same as that of the third transistor Q3, but differs by 180° (half a switching cycle). This ensures that the positive and negative half-cycle voltage pulses are symmetrical and complementary within one switching cycle. The duty cycle of the second transistor Q2 is the same as that of the fourth transistor Q4, but differs by 180° (half a switching cycle). This ensures that the positive and negative half-cycle voltage pulses are symmetrical and complementary within one switching cycle.

[0034] When the first transistor Q1 and the fourth transistor Q4 are turned on, the DC bus voltage +Vdc is applied across the primary winding L1 of transformer T (assuming A to B is positive), and the primary current flows in the forward direction. When the second transistor Q2 and the third transistor Q3 are turned on, -Vdc is applied to the winding (B to A is negative), and the primary current flows in the reverse direction.

[0035] The duty cycles of the first transistor Q1, the second transistor Q2, the third transistor Q3, and the fourth transistor Q4 are all less than 0.5. This means that within a complete switching cycle, there is a period of time during which all the switching transistors are off in a ratio of (1 - 2D), thus realizing a three-level PWM (+Vdc, 0, -Vdc). The total harmonic distortion (THD) of the three-level waveform is usually lower than that of a two-level square wave with the same switching frequency, especially the low-order harmonics, resulting in better harmonic content.

[0036] The duty cycles of transistors Q1, Q2, Q3, and Q4 are all less than 0.5, ensuring a dead time (when all primary transistors are off) in each switching cycle. During this time, the resonant current charges and discharges the junction capacitance of the switching transistors. At the moment of turn-off: the current draws charge from the MOSFET output capacitor; at the end of the dead time: the capacitor voltage is reset to 0V by the resonant current, achieving zero-voltage turn-on (ZVS).

[0037] In one embodiment, such as Figure 5As shown, the rectifier unit 22 includes a fifth transistor Q5, a sixth transistor Q6, a seventh transistor Q7, and an eighth transistor Q8. The first terminal of the fifth transistor Q5 is connected to the first terminal of the short-circuit protection module 40. The first terminal of the sixth transistor Q6 is connected to the second terminal of the fifth transistor Q5 and the first terminal of the secondary winding L2. The second terminal of the sixth transistor Q6 is connected to the second input terminal of the inverter unit 21, the second terminal of the DC voltage module 10, and the first terminal of the energy storage module 30. The first terminal of the seventh transistor Q7 is connected to the first terminal of the fifth transistor Q5. The first terminal of the eighth transistor Q8 is connected to the second terminal of the seventh transistor Q7 and the second terminal of the secondary winding L2. The second terminal of the eighth transistor Q8 is connected to the second terminal of the sixth transistor Q6.

[0038] It should be noted that at least one of the fifth transistor Q5, the sixth transistor Q6, the seventh transistor Q7, and the eighth transistor Q8 is a gallium nitride transistor (GaN transistor) or a back-to-back MOS transistor.

[0039] The fifth transistor Q5 and the eighth transistor Q8 switch synchronously, as do the sixth transistor Q6 and the seventh transistor Q7. When the first transistor Q1 and the fourth transistor Q4, or the second transistor Q2 and the third transistor Q3, are both on, the fifth transistor Q5 through the eighth transistor Q8 are off. In this case, the resonant current transfers energy to the secondary side through the transformer T. When all four transistors are off, the fifth transistor Q5 and the eighth transistor Q8, or the sixth transistor Q6 and the seventh transistor Q7, are on synchronously to provide a low-impedance freewheeling path.

[0040] The duty cycles of the fifth transistor Q5, the sixth transistor Q6, the seventh transistor Q7, and the eighth transistor Q8 are all greater than 0.5, which can ensure that they are turned on in advance before the resonant current crosses zero, realize seamless current commutation, and thus ensure the continuity of freewheeling current.

[0041] The fifth transistor Q5, the sixth transistor Q6, the seventh transistor Q7, and the eighth transistor Q8 are used to achieve asynchronous rectification, which forces these transistors to conduct during specific periods of time, constructing an inductor freewheeling path (even if the current reverses, it still flows through the MOS channel, achieving zero current turn-off, i.e., ZCS), and avoiding the conduction losses of the body diode.

[0042] In one embodiment, the duty cycle of the transistors in the inverter unit 21 is less than 0.5, and the duty cycle of the transistors in the rectifier unit 22 is greater than 0.5.

[0043] It should be noted that by controlling the operating time of the primary-side switch to less than half a cycle (D<0.5), a dead time is forcibly created to allow the resonant current to automatically prepare for the next turn-on (achieving zero-voltage turn-on, ZVS); simultaneously, the operating time of the secondary-side switch is made greater than half a cycle (D>0.5), ensuring that they turn off when the current is at its minimum / naturally crossing zero (achieving zero-current turn-off, ZVS). This perfect timing coordination between the two ensures that the main switching losses on both the primary and secondary sides are effectively eliminated under all load conditions, which significantly improves conversion efficiency and power density.

[0044] In summary, the range of △V is -△Vmax to △Vmax, and the range of Vout is Vbat - △Vmax to Vbat - + △Vmax.

[0045] For example, Vbat is 44V, design a 50V / 1KW switching power supply circuit 100.

[0046] The conventional approach is to design a 1kW 44V to 50V boost power supply with an efficiency of 95%, resulting in a system loss of 50W.

[0047] With this design, the total output power is P = (Vbat + ΔV) × Iout. The energy storage module 30 only needs to provide power of ΔV × Iout, and the remaining power is directly provided by the battery unit BAT. Therefore, only one isolated DC-DC converter module 20 (isolated D / DC power supply) with a power of (ΔV / Vout) × P = ((50-44) / 50) × 1000W = 120W needs to be designed to achieve an efficiency of over 95%, and the system loss is 6W.

[0048] Compared to the conventional solution that requires a 1kW boost power supply and incurs 50W losses, this solution only requires a 120W isolated D / DC power supply with losses of only 6W. Therefore, this solution has a smaller footprint, lower losses, and higher efficiency and power density, especially advantageous for Vout with a narrow voltage regulation range.

[0049] In one embodiment, such as Figure 6 As shown, this embodiment also provides an electronic device 200, which includes the aforementioned switching power supply circuit 100. The electronic device 200 can be consumer electronics and computer equipment, communication and network equipment, industrial automation and control systems, medical equipment, automotive equipment, or power equipment, etc.

[0050] It is understood that since the electronic device 200 provided in this embodiment includes the aforementioned switching power supply circuit 100, it can also connect a short-circuit protection module 40 in series between the second output terminal of the isolated DC-DC converter module 20 and the second terminal of the energy storage module 30. This can prevent the energy storage module 30 from short-circuiting when the two output terminals of the isolated DC-DC converter module 20 are short-circuited, thereby improving the technical problem of low safety caused by a short circuit in the energy storage module 30.

[0051] The embodiments of this utility model have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this utility model. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this utility model. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this utility model. Therefore, the content of this specification should not be construed as a limitation of this utility model.

Claims

1. A switching power supply circuit (100), characterized in that, include: A first voltage output terminal (Vout-), a second voltage output terminal (Vout+), and a DC voltage module (10), wherein the first terminal of the DC voltage module (10) is connected to the first voltage output terminal (Vout-); An isolated DC-DC converter module (20) is provided, wherein the first input terminal of the isolated DC-DC converter module (20) is connected to the first terminal and the first voltage output terminal (Vout-) of the DC voltage module (10), and the second input terminal of the isolated DC-DC converter module (20) is connected to the second terminal of the DC voltage module (10). An energy storage module (30) is provided, wherein the first end of the energy storage module (30) is connected to the second end of the DC voltage module (10), the second input end of the isolated DC-DC converter module (20), and the first output end of the isolated DC-DC converter module (20), and the second end of the energy storage module (30) is connected to the second voltage output end (Vout+). A short-circuit protection module (40) is configured to prevent the energy storage module (30) from short-circuiting. The first end of the short-circuit protection module (40) is connected to the second output end of the isolated DC-DC converter module (20), and the second end of the short-circuit protection module (40) is connected to the second end of the energy storage module (30) and the second voltage output end (Vout+).

2. The switching power supply circuit (100) according to claim 1, characterized in that, The short-circuit protection module (40) includes a first inductor (L), the first end of which is connected to the second output terminal of the isolated DC-DC converter module (20), and the second end of which is connected to the second terminal of the energy storage module (30) and the second voltage output terminal (Vout+).

3. The switching power supply circuit (100) according to claim 2, characterized in that, The energy storage module (30) includes a first capacitor (C), the first end of which is connected to the second end of the DC voltage module (10), the second input end of the isolated DC-DC converter module (20), and the first output end of the isolated DC-DC converter module (20). The second end of the first capacitor (C) is connected to the second end of the first inductor (L) and the second voltage output end (Vout+).

4. The switching power supply circuit (100) according to claim 3, characterized in that, The DC voltage module (10) includes a battery cell (BAT). The positive terminal of the battery cell (BAT) is connected to the first terminal of the first capacitor (C), the second input terminal of the isolated DC-DC converter module (20), and the first output terminal of the isolated DC-DC converter module (20). The negative terminal of the battery cell (BAT) is connected to the first input terminal and the first voltage output terminal (Vout-) of the isolated DC-DC converter module (20).

5. The switching power supply circuit (100) according to any one of claims 1-4, characterized in that, The isolated DC-DC converter module (20) includes: Inverter unit (21), the first input terminal of the inverter unit (21) is connected to the first terminal and the first voltage output terminal (Vout-) of the DC voltage module (10), and the second input terminal of the inverter unit (21) is connected to the second terminal of the DC voltage module (10) and the first terminal of the energy storage module (30); A transformer (T), wherein the first end of the primary winding (L1) of the transformer (T) is connected to the first output end of the inverter unit (21), and the second end of the primary winding (L1) of the transformer (T) is connected to the second output end of the inverter unit (21). The rectifier unit (22) has its first input terminal connected to the first end of the secondary winding (L2) of the transformer (T), its second input terminal connected to the second end of the secondary winding (L2) of the transformer (T), its first output terminal connected to the second input terminal of the inverter unit (21), the second end of the DC voltage module (10) and the first end of the energy storage module (30), and its second output terminal connected to the first end of the short-circuit protection module (40).

6. The switching power supply circuit (100) according to claim 5, characterized in that, The inverter unit (21) includes: The first transistor (Q1) has its first terminal connected to the second terminal of the DC voltage module (10) and the first terminal of the energy storage module (30); The second transistor (Q2) has its first terminal connected to the second terminal of the first transistor (Q1) and the first end of the primary winding (L1), and its second terminal connected to the first end of the DC voltage module (10) and the first voltage output terminal (Vout-). The third transistor (Q3) has its first terminal connected to the first terminal of the first transistor (Q1); The fourth transistor (Q4) has its first terminal connected to the second terminal of the third transistor (Q3) and the second terminal of the primary winding (L1), and its second terminal connected to the second terminal of the second transistor (Q2).

7. The switching power supply circuit (100) according to claim 5, characterized in that, The rectifier unit (22) includes: The fifth transistor (Q5) has its first terminal connected to the first terminal of the short-circuit protection module (40); The sixth transistor (Q6) has its first terminal connected to the second terminal of the fifth transistor (Q5) and the first terminal of the secondary winding (L2). The second terminal of the sixth transistor (Q6) is connected to the second input terminal of the inverter unit (21), the second terminal of the DC voltage module (10), and the first terminal of the energy storage module (30). The seventh transistor (Q7) has its first terminal connected to the first terminal of the fifth transistor (Q5); The eighth transistor (Q8) has its first terminal connected to the second terminal of the seventh transistor (Q7) and the second terminal of the secondary winding (L2), and its second terminal connected to the second terminal of the sixth transistor (Q6).

8. The switching power supply circuit (100) according to claim 7, characterized in that, The rectifier unit (22) operates in asynchronous rectification mode.

9. The switching power supply circuit (100) according to claim 5, characterized in that, The duty cycle of the transistors in the inverter unit (21) is less than 0.5, and the duty cycle of the transistors in the rectifier unit (22) is greater than 0.

5.

10. An electronic device (200), characterized in that, The electronic device (200) includes a switching power supply circuit (100) as described in any one of claims 1-9.

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