Switching power supply and electronic equipment

Abstract

The present application discloses a switching power supply and an electronic device, wherein the switching power supply comprises: an inverter module, the input end of the inverter module is configured to receive a first DC signal; a resonance module, the input end of the resonance module is connected to the output end of the inverter module; a transformer module, the input end of the transformer module is connected to the output end of the resonance module; a rectifier module, the input end of the rectifier module is connected to the output end of the transformer module, and the output end of the rectifier module is configured to output a second DC signal; a control module, connected to the control end of the inverter module, and the control module is configured to output a constant frequency control signal to the control end of the inverter module, so that the resonance module works at a resonance point. Through the above method, the stability of the output voltage of the switching power supply can be guaranteed.

Description

Technical Field

[0001] The present application relates to the technical field of electronic circuits, and in particular to a switching power supply and an electronic device. Background Art

[0002] Switching power supply is a kind of power supply widely used in various electronic devices.

[0003] The general control method of LLC switching power supply is to use optocoupler as the primary and secondary isolation feedback signal. The existing LLC switching power supply technology mainly includes using optocoupler isolation feedback loop to feed back the sampled value of the output voltage to the feedback end of the control chip, thereby adjusting the switching frequency of the switch tube to achieve output voltage stability, which belongs to variable frequency control. However, the voltage resistance level of optocoupler is 5kV, so it cannot meet the high voltage resistance requirements of the primary and secondary. Summary of the invention

[0004] In order to solve the above problems, the present application provides a switching power supply and an electronic device, which can ensure the stability of the output voltage of the switching power supply and meet the high withstand voltage requirements of the primary and secondary.

[0005] A technical solution adopted in the present application is: to provide a switching power supply, which includes: an inverter module, the input end of the inverter module is configured to receive a first DC signal; a resonance module, the input end of the resonance module is connected to the output end of the inverter module; a transformer module, the input end of the transformer module is connected to the output end of the resonance module; a rectifier module, the input end of the rectifier module is connected to the output end of the transformer module, and the output end of the rectifier module is configured to output a second DC signal; a control module, connected to the control end of the inverter module, the control module is configured to output a constant frequency control signal to the control end of the inverter module, so that the resonance module operates at a resonance point.

[0006] In one embodiment, the control module includes: a switch control chip, the output end of which is connected to the control end of the inverter module; and a peripheral circuit connected to the feedback end of the switch control chip, the feedback end being connected to the feedback module inside the switch control chip. The peripheral circuit is configured to adjust the feedback signal of the feedback end so that the switch control chip outputs a control signal of a constant frequency.

[0007] In one embodiment, the feedback module includes a voltage divider module, a first end of the voltage divider module is connected to the feedback end, a second end of the voltage divider module is connected to the primary ground, and the frequency of the control signal output by the switch control chip is determined by the voltage of the voltage divider node of the voltage divider module.

[0008] In one embodiment, the peripheral circuit is configured to adjust the voltage of the feedback terminal to be constant.

[0009] In one embodiment, the peripheral circuit includes a first constant voltage source, an output terminal of the first constant voltage source is connected to the feedback terminal, and the constant voltage source is configured to provide a constant voltage.

[0010] In one embodiment, the feedback module includes: a first resistor, a first end of the first resistor is connected to the feedback end; a second resistor, a first end of the second resistor is connected to the second end of the first resistor, and the second end of the second resistor is connected to the primary ground; a comparator, a non-inverting input end of the comparator is connected to the first end of the second resistor, and an inverting input end of the comparator is configured to input a reference voltage; a Zener diode, a positive electrode of the Zener diode is connected to the primary ground, and a negative electrode of the Zener diode is connected to the non-inverting input end of the comparator.

[0011] In one embodiment, the feedback module includes a second constant voltage source and a third resistor, the first end of the third resistor is connected to the feedback end, the second end of the third resistor is connected to the output end of the second constant voltage source, and the frequency of the control signal output by the switch control chip is determined by the current flowing through the third resistor.

[0012] In one embodiment, the peripheral circuit is configured to adjust the current at the feedback terminal to be constant.

[0013] In one embodiment, the peripheral circuit includes a fourth resistor, a first end of the fourth resistor is connected to the feedback end, and a second end of the fourth resistor is connected to the primary ground.

[0014] In one embodiment, the control module includes an MCU (Micro Controller Unit) chip, and the MCU chip is configured to output a control signal of a constant frequency to a control terminal of the inverter module, so that the resonance module operates at a resonance point.

[0015] In one embodiment, the inverter module includes: a first transistor, a first end of the first transistor is configured to receive a first DC signal; a second transistor, a first end of the second transistor is connected to a second end of the first transistor, and a second end of the second transistor is connected to a primary ground.

[0016] In one embodiment, the control module includes a first driving end and a second driving end, the first driving end is connected to the control end of the first transistor; the second driving end is connected to the control end of the second transistor; the first driving end is configured to output a first control signal, and the second driving end is configured to output a second control signal.

[0017] Another technical solution adopted by the present application is to provide an electronic device, which includes the above-mentioned switching power supply.

[0018] The switching power supply provided by the present application includes: an inverter module, the input end of the inverter module is configured to receive a first DC signal; a resonance module, the input end of the resonance module is connected to the output end of the inverter module; a transformer module, the input end of the transformer module is connected to the output end of the resonance module; a rectifier module, the input end of the rectifier module is connected to the output end of the transformer module, and the output end of the rectifier module is configured to output a second DC signal; a control module, connected to the control end of the inverter module, the control module is configured to output a constant frequency control signal to the control end of the inverter module, so that the resonance module works at the resonance point. In the above manner, the constant signal is used as a feedback signal to make the switching power supply work at a resonance frequency point with a constant gain of 1, realize fixed frequency control, ensure the stable output of the switching power supply, and improve the withstand voltage level between the primary and secondary. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. Among them:

[0020] Figure 1 It is a structural schematic diagram of the first embodiment of the switching power supply provided by the present application;

[0021] Figure 2 is a structural schematic diagram of a second embodiment of a switching power supply provided by the present application;

[0022] Figure 3 is a structural schematic diagram of a third embodiment of a switching power supply provided by the present application;

[0023] Figure 4 is a specific schematic diagram of the third embodiment of the switching power supply provided by the present application;

[0024] Figure 5 is a structural schematic diagram of a fourth embodiment of a switching power supply provided by the present application;

[0025] Figure 6 is a specific schematic diagram of a fourth embodiment of the switching power supply provided by the present application;

[0026] Figure 7 is a structural schematic diagram of a fifth embodiment of a switching power supply provided by the present application;

[0027] Figure 8 It is a specific schematic diagram of the fifth embodiment of the switching power supply provided by the present application. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. It will be appreciated that the specific embodiments described herein are only used to explain the present application, rather than to limit the present application. It should also be noted that, for ease of description, only some but not all structures related to the present application are shown in the drawings. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the art without making creative work are within the scope of protection of the present application.

[0029] The terms "first", "second", etc. in this application are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. 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 optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices.

[0030] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0031] See also Figure 1 , Figure 1 1 is a schematic diagram of the structure of the first embodiment of the switching power supply provided by the present application. The switching power supply 1000 comprises an inverter module 100 , a resonance module 200 , a transformer module 300 , a rectifier module 400 and a control module 500 .

[0032] Among them, the input end of the inverter module 100 is configured to receive a first DC signal S1; the input end of the resonance module 200 is connected to the output end of the inverter module 100; the input end of the transformer module 300 is connected to the output end of the resonance module 200; the input end of the rectifier module 400 is connected to the output end of the transformer module 300, and the output end of the rectifier module 400 is configured to output a second DC signal S2; the control module 500 is connected to the control end of the inverter module 100, and the control module 500 is configured to output a constant frequency control signal to the control end of the inverter module 100, so that the resonance module 200 operates at the resonance point.

[0033] Optionally, the input end of the inverter module 100 is configured to receive a first DC signal S1, process the first DC signal S1, and output an AC signal (e.g., a square wave signal). The first DC signal S1 may be, for example, a 400V DC voltage provided by a PFC (Power Factor Correction) boost circuit, which is not specifically limited herein.

[0034] Optionally, the input end of the resonance module 200 is connected to the output end of the inverter module 100, and is used to receive the AC signal output by the inverter module 100. The resonance module 200 is an LLC (a resonance circuit composed of inductance, leakage inductance, and capacitance in series, L refers to Lnductance; C refers to Capacitance) resonance circuit. When the LLC resonance circuit is purely resistive, the resonance circuit operates at the resonance point, and the output voltage gain at this time is 1.

[0035] Optionally, the input end of the transformer module 300 is connected to the output end of the resonance module 200 , and is used to convert a high-frequency AC signal of one voltage level output by the resonance module 200 into a high-frequency AC signal of another voltage level.

[0036] Optionally, the input end of the rectifier module 400 is connected to the output end of the transformer module 300, and the output end of the rectifier module 400 is configured to output the second DC signal S2. The rectifier module 400 is used to rectify the high-frequency AC signal output by the transformer module 300 and output the second DC signal S2.

[0037] Furthermore, the control module 500 serves as the core control module of the switching power supply 1000, is connected to the control end of the inverter module 100, and outputs a control signal of a constant frequency to the control end of the inverter module 100, so as to achieve a constant frequency of the square wave signal output by the inverter module, so that the resonance module 200 operates at a resonance frequency point with a gain of 1, thereby allowing the switching power supply 1000 to operate at a resonance point of a constant frequency.

[0038] It can be understood that, through the above method, the control module 500 is used as the key hub of the switching power supply 1000 to control the inverter module 100 and the resonance module 200, and cooperates with the transformer module 300 and the rectifier module 400, so that the switching power supply 1000 operates at a resonance point where the output voltage gain is constantly 1, and a fixed frequency control is realized, thereby ensuring the stable output of the switching power supply 1000 and improving the withstand voltage level between the primary and secondary.

[0039] See also Figure 2 , Figure 2 1 is a schematic diagram of the structure of the second embodiment of the switching power supply provided by the present application. The switching power supply 1000 comprises an inverter module 100 , a resonance module 200 , a transformer module 300 , a rectifier module 400 and a control module 500 .

[0040] Among them, the input end of the inverter module 100 is configured to receive a first DC signal S1; the input end of the resonance module 200 is connected to the output end of the inverter module 100; the input end of the transformer module 300 is connected to the output end of the resonance module 200; the input end of the rectifier module 400 is connected to the output end of the transformer module 300, and the output end of the rectifier module 400 is configured to output a second DC signal S2; the control module 500 is connected to the control end of the inverter module 100, and the control module 500 is configured to output a constant frequency control signal to the control end of the inverter module 100, so that the resonance module 200 operates at the resonance point.

[0041] Optionally, the control module 500 includes a switch control chip 510 and a peripheral circuit 520 , wherein the output end of the switch control chip 510 is connected to the control end of the inverter module 100 ; and the peripheral circuit 520 is connected to the feedback end FB (Feedback) of the switch control chip 510 .

[0042] Specifically, the peripheral circuit 520 is configured to adjust the feedback signal at the feedback terminal so that the switch control chip 510 outputs a control signal with a constant frequency.

[0043] Optionally, the inverter module 100 includes a first transistor Q1 and a second transistor Q2, wherein the first end of the first transistor Q1 is configured to receive a first DC signal S1; the first end of the second transistor Q2 is connected to the second end of the first transistor Q1, and the second end of the second transistor Q2 is connected to the primary ground.

[0044] Optionally, the control module 500 further includes a first driver end high side driver (Hdriv, High Driver) and a second driver end low side driver (Ldriv, Low Driver), the first driver end Hdriv is connected to the control end of the first transistor Q1; the second driver end Ldriv is connected to the control end of the second transistor Q2. The first driver end Hdriv is configured to output a first control signal, and the second driver end Ldriv is configured to output a second control signal.

[0045] Specifically, the first driving terminal Hdriv and the second driving terminal Ldriv control the switching frequency of the first transistor Q1 and the second transistor Q2 , thereby adjusting the output frequency of the AC signal of the inverter module 100 .

[0046] See also Figure 3 , Figure 3 1 is a schematic diagram of the structure of the third embodiment of the switching power supply provided by the present application. The switching power supply 1000 comprises: an inverter module 100 , a resonance module 200 , a transformer module 300 , a rectifier module 400 and a control module 500 .

[0047] Among them, the input end of the inverter module 100 is configured to receive a first DC signal; the input end of the resonance module 200 is connected to the output end of the inverter module 100; the input end of the transformer module 300 is connected to the output end of the resonance module 200; the input end of the rectifier module 400 is connected to the output end of the transformer module 300, and the output end of the rectifier module 400 is configured to output a second DC signal; the control module 500 is connected to the control end of the inverter module 100, and the control module 500 is configured to output a constant frequency control signal to the control end of the inverter module 100, so that the resonance module 200 operates at the resonance point.

[0048] Optionally, the feedback module of the switch control chip 510 includes a voltage divider module 511, a first end of the voltage divider module 511 is connected to the feedback end FB, and a second end of the voltage divider module 511 is connected to the primary ground. Specifically, the frequency of the control signal output by the switch control chip 510 is determined by the voltage of the voltage divider node of the voltage divider module 511.

[0049] Optionally, the feedback module of the switch control chip 510 further includes a comparator A1 , a voltage stabilizing diode Z1 , a first resistor R1 , and a second resistor R2 .

[0050] Specifically, the non-inverting input terminal of the comparator A1 is connected to the first end of the second resistor R2, and the inverting input terminal of the comparator A1 is configured to input a reference voltage; the positive electrode of the Zener diode Z1 is grounded, and the negative electrode of the Zener diode Z1 is connected to the non-inverting input terminal of the comparator A1; the first end of the first resistor R1 is connected to the feedback terminal FB; the first end of the second resistor R2 is connected to the second end of the first resistor R1, and the second end of the second resistor R2 is connected to the primary ground.

[0051] Optionally, the peripheral circuit 520 includes a first constant voltage source Vf, an output terminal of the first constant voltage source Vf is connected to the feedback terminal FB, and the first constant voltage source Vf is configured to provide a constant voltage.

[0052] See also Figure 4 , Figure 4 It is a specific schematic diagram of the third embodiment of the switching power supply provided by the present application.

[0053] Among them, the inverter module 100 includes a PFC circuit, a first capacitor C1, a first MOS tube Q1 and a second MOS tube Q2; the resonance module 200 includes a first inductor Lr, a second capacitor C2 and a second inductor Lm; the transformer module 300 includes a transformer T1; the rectifier module 400 includes a first diode D1, a second diode D2 and a third capacitor C3; the control module 500 includes a first drive end HDriv, a second drive end LDriv, a first resistor R1, a second resistor R2, a voltage regulator diode Z1, a comparator A1 and a first constant voltage source Vf.

[0054] Specifically, the PFC circuit is connected in parallel with the first capacitor C1; the drain of the first MOS tube Q1 is connected to the positive electrode of the PFC circuit, the source of the second MOS tube Q2 is connected to the negative electrode of the PFC and connected to the primary ground, the source of the first MOS tube Q1 is connected to the drain of the second MOS tube Q2 and connected to the first end of the first inductor Lr; the second end of the first inductor Lr is connected to the first end of the primary winding of T1 and the first end of the second inductor Lm, the second end of the second inductor Lm is connected to the first end of the second capacitor C2 and the second end of the primary winding of T1, and the second end of the second capacitor C2 is connected to the primary ground; the first end of the secondary winding of T1 is connected to the positive electrode of the first diode D1, and the third end of the secondary winding of T1 is connected to the positive electrode of the second diode D2; the negative electrodes of the first diode D1 and the second diode D2 are connected together and connected to the positive electrode of the third capacitor C3. The first driving terminal HDriv is connected to the gate of the first MOS tube Q1, and the second driving terminal LDriv is connected to the gate of the second MOS tube Q2; the first end of the first resistor R1 of the feedback module of the switch control chip is connected to the feedback terminal FB, the first end of the second resistor R2 is connected to the second end of the first resistor R1, and the second end of the second resistor R2 is grounded, the non-inverting input terminal of the comparator A1 is connected to the first end of the second resistor R2, and the inverting input terminal of the comparator A1 is configured to input a reference voltage of 0.5V, the positive electrode of the Zener diode Z1 is grounded, and the negative electrode of the Zener diode Z1 is connected to the non-inverting input terminal of the comparator A1; the positive electrode of the first constant voltage source Vf of the peripheral circuit is connected to the feedback terminal FB, and the negative electrode of the first constant voltage source Vf is connected to the primary ground.

[0055] See also Figure 5 , Figure 5 1 is a schematic diagram of the structure of the fourth embodiment of the switching power supply provided by the present application. The switching power supply 1000 comprises: an inverter module 100 , a resonance module 200 , a transformer module 300 , a rectifier module 400 and a control module 500 .

[0056] Among them, the input end of the inverter module 100 is configured to receive a first DC signal; the input end of the resonance module 200 is connected to the output end of the inverter module 100; the input end of the transformer module 300 is connected to the output end of the resonance module 200; the input end of the rectifier module 400 is connected to the output end of the transformer module 300, and the output end of the rectifier module 400 is configured to output a second DC signal; the control module 500 is connected to the control end of the inverter module 100, and the control module 500 is configured to output a constant frequency control signal to the control end of the inverter module 100, so that the resonance module 200 operates at the resonance point.

[0057] Optionally, the feedback module of the switch control chip 510 includes a second constant voltage source Vs and a third resistor R3, the first end of the third resistor R3 is connected to the feedback end FB, the second end of the third resistor R3 is connected to the output end of the second constant voltage source Vs, and the frequency of the control signal output by the switch control chip 510 is determined by the current flowing through the third resistor R3.

[0058] Optionally, the peripheral circuit 520 includes a fourth resistor R4, a first end of the fourth resistor R4 is connected to the feedback end FB, and a second end of the fourth resistor R4 is connected to the primary ground.

[0059] See also Figure 6 , Figure 6 It is a specific schematic diagram of the fourth embodiment of the switching power supply provided by the present application.

[0060] Among them, the inverter module 100 includes a PFC circuit, a first capacitor C1, a first MOS tube Q1 and a second MOS tube Q2; the resonance module 200 includes a first inductor Lr, a second capacitor C2 and a second inductor Lm; the transformer module 300 includes a transformer T1; the rectifier module 400 includes a first diode D1, a second diode D2 and a third capacitor C3; the control module 500 includes a first drive end high-end driver HDriv, a second drive end low-end driver LDriv, a third resistor R3, a fourth resistor R4 and a second constant voltage source Vs.

[0061] The PFC circuit is connected in parallel with the first capacitor C1; the drain of the first MOS tube Q1 is connected to the positive electrode of the PFC circuit, the source of the second MOS tube Q2 is connected to the negative electrode of the PFC circuit and connected to the primary ground, the source of the first MOS tube Q1 is connected to the drain of the second MOS tube Q2 and connected to the first end of the first inductor Lr; the second end of the first inductor Lr is connected to the first end of the primary winding of T1 and the first end of the second inductor Lm, the second end of the second inductor Lm is connected to the first end of the second capacitor C2 and the second end of the primary winding of T1, and the second end of the second capacitor C2 is connected to the primary ground; the first end of the secondary winding of T1 is connected to the positive electrode of the first diode D1, and the secondary winding of T1 is connected to the positive electrode of the first diode D1. The third end of the winding is connected to the positive electrode of the second diode D2; the negative electrodes of the first diode D1 and the second diode D2 are connected together and connected to the positive electrode of the third capacitor C3, the negative electrode of the third capacitor C3 is connected to the secondary ground and connected to the second end of the secondary winding of T1; the first driving end HDriv is connected to the gate of the first MOS tube Q1, the second driving end LDriv is connected to the gate of the second MOS tube Q2, the first end of the third resistor R3 is connected to the feedback end FB, the second end of the third resistor R3 is connected to the positive electrode of the second constant voltage source Vs, the negative electrode of the second constant voltage source Vs is grounded, the first end of the fourth resistor R4 is connected to the feedback end FB, and the second end of the fourth resistor R4 is connected to the primary ground.

[0062] See also Figure 7 , Figure 71 is a schematic diagram of the structure of the fifth embodiment of the switching power supply provided by the present application. The switching power supply 1000 comprises: an inverter module 100 , a resonance module 200 , a transformer module 300 , a rectifier module 400 and a control module 500 .

[0063] Among them, the input end of the inverter module 100 is configured to receive a first DC signal; the input end of the resonance module 200 is connected to the output end of the inverter module 100; the input end of the transformer module 300 is connected to the output end of the resonance module 200; the input end of the rectifier module 400 is connected to the output end of the transformer module 300, and the output end of the rectifier module 400 is configured to output a second DC signal; the control module 500 is connected to the control end of the inverter module 100, and the control module 500 is configured to output a constant frequency control signal to the control end of the inverter module 100, so that the resonance module 200 operates at the resonance point.

[0064] Optionally, the control module 500 includes an MCU chip, and the MCU chip is configured to output a control signal of a constant frequency to a control end of the inverter module 100 so that the resonance module 200 operates at a resonance point.

[0065] See also Figure 8 , Figure 8 It is a specific schematic diagram of the fifth embodiment of the switching power supply provided by the present application.

[0066] Among them, the inverter module 100 includes a PFC circuit, a first capacitor C1, a first MOS tube Q1 and a second MOS tube Q2; the resonance module 200 includes a first inductor Lr, a second capacitor C2 and a second inductor Lm; the transformer module 300 includes a transformer T1; the rectifier module 400 includes a first diode D1, a second diode D2 and a third capacitor C3; the control module 500 includes an MCU chip, and the MCU chip includes a first drive end HDriv and a second drive end LDriv.

[0067] The PFC circuit is connected in parallel with the first capacitor C1; the drain of the first MOS transistor Q1 is connected to the positive electrode of the PFC circuit, the source of the second MOS transistor Q2 is connected to the negative electrode of the PFC circuit and connected to the primary ground, the source of the first MOS transistor Q1 is connected to the drain of the second MOS transistor Q2 and connected to the first end of the first inductor Lr; the second end of the first inductor Lr is connected to the first end of the primary winding of T1 and the first end of the second inductor Lm, the second end of the second inductor Lm is connected to the first end of the second capacitor C2 and the second end of the primary winding of T1, and the second end of the second capacitor C2 is connected to the primary ground; the first end of the secondary winding of T1 is connected to the positive electrode of the first diode D1, and the third end of the secondary winding of T1 is connected to the positive electrode of the second diode D2; the negative electrodes of the first diode D1 and the second diode D2 are connected together and connected to the positive electrode of the third capacitor C3, and the negative electrode of the third capacitor C3 is connected to the secondary ground and connected to the second end of the secondary winding of T1; the first driving end HDriv is connected to the gate of the first MOS transistor Q1, and the second driving end LDriv is connected to the gate of the second MOS transistor Q2.

[0068] When the switching power supply of this embodiment is applied to electronic equipment, the control module is used as the key hub to call the inverter module, the resonance module, etc., and cooperate with the transformer module and the rectifier module, so that the switching power supply operates at a resonance point where the output voltage gain is constantly 1, realizing fixed frequency control, ensuring the stable output of the switching power supply, and improving the withstand voltage level between the primary and secondary.

[0069] The above description is only an implementation method of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A switching power supply, It is characterized in that The switching power supply comprises: An inverter module, wherein an input end of the inverter module is configured to receive a first DC signal; A resonance module, wherein an input end of the resonance module is connected to an output end of the inverter module; A transformer module, wherein an input end of the transformer module is connected to an output end of the resonance module; A rectifier module, wherein an input end of the rectifier module is connected to an output end of the transformer module, and an output end of the rectifier module is configured to output a second DC signal; A control module, comprising a switch control chip and a peripheral circuit, wherein the output end of the switch control chip is connected to the control end of the inverter module, the peripheral circuit is connected to the feedback module of the switch control chip via the feedback end of the switch control chip, and the peripheral circuit is configured to adjust the voltage or current of the feedback signal of the feedback end to be constant, so that the switch control chip outputs a control signal of a constant frequency to the control end of the inverter module, so that the resonance module operates at a resonance point; Wherein, the switch control chip comprises a first feedback module, the first feedback module comprises a voltage divider module, a first end of the voltage divider module is connected to the feedback end, a second end of the voltage divider module is connected to the primary ground, and the frequency of the control signal output by the switch control chip is determined by the voltage of the voltage divider node of the voltage divider module; the peripheral circuit comprises a first constant voltage source, an output end of the first constant voltage source is connected to the feedback end, and the constant voltage source is configured to provide a constant voltage; or The switch control chip includes a second feedback module, the second feedback module includes a second constant voltage source and a third resistor, the first end of the third resistor is connected to the feedback end, the second end of the third resistor is connected to the output end of the second constant voltage source, and the frequency of the control signal output by the switch control chip is determined by the current flowing through the third resistor; the peripheral circuit includes a fourth resistor, the first end of the fourth resistor is connected to the feedback end, and the second end of the fourth resistor is connected to the primary ground.

2. The switching power supply according to claim 1, It is characterized in that The voltage divider module comprises: a first resistor, wherein a first end of the first resistor is connected to the feedback end; a second resistor, wherein a first end of the second resistor is connected to a second end of the first resistor, and a second end of the second resistor is connected to a primary ground; The first feedback module also includes: A comparator, wherein a non-inverting input terminal of the comparator is connected to the first end of the second resistor, and an inverting input terminal of the comparator is configured to input a reference voltage; A voltage stabilizing diode, wherein the anode of the voltage stabilizing diode is grounded, and the cathode of the voltage stabilizing diode is connected to the non-inverting input terminal of the comparator.

3. The switching power supply according to claim 1, It is characterized in that The inverter module comprises: a first transistor, wherein a first terminal of the first transistor is configured to receive the first DC signal; a second transistor, wherein a first terminal of the second transistor is connected to a second terminal of the first transistor, and a second terminal of the second transistor is connected to a primary ground; The control module includes a first driving end and a second driving end, the first driving end is connected to the control end of the first transistor, the second driving end is connected to the control end of the second transistor, the first driving end is configured to output a first control signal, and the second driving end is configured to output a second control signal.

4. An electronic device, It is characterized in that The electronic device comprises the switching power supply according to any one of claims 1 to 3.

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