Power supply circuit and power adapter

Abstract

The present application relates to the field of electronic technology, and more particularly to a power supply circuit and a power supply adapter. The power supply circuit includes a transformer and rectifier module, a first feedback module, and a control module. The first feedback module is connected to the output end of the transformer and rectifier module and is used to detect the magnitude relationship between a variable voltage signal output by the transformer and rectifier module and a reference output voltage signal to generate a feedback signal. The control module is connected to the first feedback module and the transformer and rectifier module, respectively, and is used to control the conduction of a switching device in the transformer and rectifier module according to the feedback signal to reduce the difference between the variable voltage signal and the reference output voltage signal, thereby stabilizing the output variable voltage at the reference voltage. The present application can achieve the beneficial effects of improving conversion efficiency and voltage stabilization performance based on the output voltage of the power supply circuit.

Description

Technical Field

[0001] The present application relates to the field of electronic technology, and in particular to a power supply circuit and a power supply adapter. Background Art

[0002] A power adapter is a device that converts AC power to DC power and is widely used in various electronic products. With the development of technology, the requirements for power supply circuits are becoming increasingly higher. They must not only be able to efficiently convert and regulate voltage, but also have good stability and reliability.

[0003] For traditional power supply circuits, most of them use two-stage circuits to realize power conversion and transmission and adjust the output voltage. However, such circuits often have many components and complex circuit structures, resulting in low conversion efficiency. How to simplify the circuit structure based on the output voltage of the power supply circuit and improve the conversion efficiency and voltage regulation performance is a technical problem that needs to be solved urgently. Summary of the Invention

[0004] The present application provides a power supply circuit and a power supply adapter, which can achieve the beneficial effects of improving conversion efficiency and voltage regulation performance based on the output voltage of the power supply circuit.

[0005] In a first aspect of the present application, a power supply circuit is provided, comprising:

[0006] The transformer and rectifier module is used to receive an input voltage signal and perform rectification and voltage transformation on the input voltage signal to obtain a transformed voltage signal;

[0007] a first feedback module, connected to the output end of the transformer and rectifier module, configured to obtain the transformed voltage signal and a reference output voltage signal, and generate a first feedback signal based on the transformed voltage signal and the reference output voltage signal, wherein the first feedback signal is used to express a magnitude relationship between the transformed voltage signal and the reference output voltage signal;

[0008] a control module, connected to the first feedback module and the transformer and rectifier module respectively, configured to receive the first feedback signal and generate a first control signal according to the first feedback signal;

[0009] The transformer and rectifier module is further configured to receive the first control signal and control the conduction of the switch device according to the first control signal to reduce the difference between the transformed voltage signal and the reference output voltage signal.

[0010] By adopting the above technical solution, the first feedback module determines the magnitude relationship between the input voltage signal and the transformed voltage signal based on the input voltage and the voltage output by the transformer and rectifier module, thereby obtaining a corresponding first feedback signal. The control module generates a first control signal based on the first feedback signal, thereby controlling the conduction of the switching device in the transformer and rectifier module, adaptively adjusting the conduction status of the switching device, and outputting a stable output voltage.

[0011] Optionally, the control module includes:

[0012] a comparator, connected to the first feedback module, configured to receive the first feedback signal and determine, based on the first feedback signal, whether the voltage value of the variable voltage signal is greater than the voltage value of the reference output voltage signal;

[0013] A processor is connected to the comparator and is used to obtain the input voltage signal, the variable voltage signal and the reference output voltage signal when the voltage value of the variable voltage signal is greater than the voltage value of the reference output voltage signal, and generate a first control signal based on the input voltage signal, the variable voltage signal and the reference output voltage signal.

[0014] By adopting the above technical solution, the control module of the power supply circuit adopts the structure of a comparator and a processor. Through the coordinated work of the two, the output voltage situation can be accurately judged. If the voltage value of the variable voltage signal is greater than the voltage value of the reference output voltage signal, the processor generates a first control signal based on the input voltage signal, the variable voltage signal and the reference output voltage signal, and further adjusts the working state of the transformer and rectifier module, thereby reducing the difference between the variable voltage signal and the reference output voltage signal, and improving the reliability and overall performance of the power supply circuit.

[0015] Optionally, the processor is configured to:

[0016] Determining a voltage step-up ratio and a voltage step-down ratio according to the input voltage signal and the variable voltage signal;

[0017] If the boost ratio is greater than or equal to the buck ratio, determining to perform buck control on the input voltage signal according to the variable voltage signal, the reference output voltage signal, and the boost and buck ratios;

[0018] If the voltage-boosting ratio is smaller than the voltage-buckling ratio, it is determined to perform voltage-boosting control on the input voltage signal according to the variable voltage signal, the reference output voltage signal, and the voltage-boosting and voltage-buckling ratios.

[0019] By adopting the above technical solution, the processor can accurately calculate the duty cycle required for boosting and bucking based on the analysis of the input voltage signal and the variable voltage signal. When the boost ratio is greater than or equal to the buck ratio, the buck control strategy is selected. Conversely, when the boost ratio is less than the buck ratio, the boost control strategy is selected to obtain the required output voltage.

[0020] Optionally, the processor is configured to:

[0021] Determining a maximum value and a minimum value of the variable voltage signal according to the variable voltage signal;

[0022] determining a new boost ratio according to the maximum value and the minimum value of the variable voltage signal, the boost ratio, and the reference output voltage signal;

[0023] The first control signal is generated according to the new boost ratio.

[0024] By adopting the above technical solution, the processor can dynamically adjust the boost ratio according to the maximum and minimum values ​​of the variable voltage signal and the existing boost ratio, thereby ensuring that the output voltage is always close to the reference output voltage signal, reducing voltage fluctuations and improving the stability and efficiency of the power supply circuit.

[0025] Optionally, the processor is configured to:

[0026] Determining a new boost duration and a new buck duration within a preset time period according to the new boost ratio;

[0027] The first control signal is generated according to the boost duration and the buck duration.

[0028] By adopting the above technical solution, after the processor determines the new boost ratio, it can calculate the boost duration within a preset time period, and then determine the buck duration. By calculating and controlling the boost and buck durations, the on and off of the switching device can be effectively controlled to prevent excessive switching, reduce the voltage fluctuation range, and thus improve the voltage stabilization performance.

[0029] Optionally, the transformer and rectifier module includes a transformer and a synchronous rectification unit;

[0030] The second input terminal and the second output terminal of the transformer are connected to the control module respectively, and the three output terminals of the transformer are connected to the input terminal and the output terminal of the synchronous rectification unit;

[0031] The first input terminal of the transformer is used to receive the input voltage signal;

[0032] The second output terminal of the transformer is used to output a variable voltage signal.

[0033] By adopting the above technical solution, when the power adapter is working, the transformer receives the input voltage signal and outputs a variable voltage signal through electromagnetic induction. Combined with the synchronous rectification module, the variable voltage output by the transformer is ripple rectified to reduce harmonic interference and make the final variable voltage more stable.

[0034] Optionally, the transformer and rectifier module further includes: an auxiliary winding, a first MOS tube, a first diode and a first transistor;

[0035] One end of the auxiliary winding is connected to the first input end of the transformer, the other end of the auxiliary winding is connected to the collector of the first transistor, the base of the first transistor is connected to the control module, the emitter of the first transistor is connected to the cathode of the first diode, and the anode of the first diode is connected to the connection between the control module and the first transistor;

[0036] The connection point between the control module, the first transistor and the first diode is connected to the gate of the first MOSFET, and the source of the first MOSFET is connected to the connection point between the first transistor and the auxiliary winding;

[0037] The drain of the first MOS tube is used to receive the input voltage signal.

[0038] By adopting the above technical solution, when receiving the input voltage signal, the first MOSFET can adapt to the change of the input voltage under the drive of the control module. At the same time, with the help of the first diode and the first transistor, the energy stored in the transformer can be released when the first MOSFET is turned off, preventing excessive reverse voltage from damaging the circuit, thereby improving the safety and reliability of the circuit.

[0039] Optionally, the transformer and rectifier module further includes a second MOS tube, a second diode and a second transistor;

[0040] The other end of the auxiliary winding is connected to the drain of the second MOSFET, the gate of the second MOSFET is connected to the emitter of the second transistor, the base of the second transistor is connected to the control module, and the source of the second MOSFET and the collector of the second transistor are grounded;

[0041] The anode of the second diode is connected to the connection point between the second transistor and the control module, and the cathode of the second diode is connected to the connection point between the second MOS transistor and the second transistor.

[0042] By adopting the above technical solution, when the input voltage signal is received, the second diode and the second transistor are used to realize detection of the control module, thereby facilitating the output of the subsequent transformer and rectifier module.

[0043] Optionally, the power supply circuit further includes: a noise voltage suppression module;

[0044] The input end of the noise voltage suppression module is connected to the external alternating current, and is used to determine the voltage suppression signal according to the voltage of the alternating current. The output end of the noise voltage suppression module is connected to the drain of the first MOS tube, and is used to determine the input voltage signal according to the voltage suppression signal.

[0045] By adopting the above technical solution, the noise voltage suppression module obtains a voltage suppression signal based on the external AC power, thereby performing noise voltage suppression and filtering out common-mode interference signals in the AC power, thereby preventing these interference signals from affecting the normal operation of subsequent circuits, making the input voltage more stable, and thereby improving the conversion efficiency and output accuracy of the transformer and rectifier module, and enhancing the overall anti-interference capability of the power supply circuit.

[0046] In a second aspect of the present application, a power adapter is provided, comprising the power circuit as described above.

[0047] In summary, this application includes at least one of the following beneficial technical effects:

[0048] 1. The first feedback module determines the magnitude relationship between the input voltage signal and the transformed voltage signal based on the input voltage and the voltage output by the transformer-rectifier module, thereby obtaining a corresponding first feedback signal. The control module then generates a first control signal based on the first feedback signal, thereby controlling the conduction of the switching device in the transformer-rectifier module and adaptively adjusting the conduction of the switching device to output a stable output voltage.

[0049] 2. The noise voltage suppression module obtains a voltage suppression signal based on the external AC power, thereby performing noise voltage suppression and filtering out common-mode interference signals in the AC power to prevent these interference signals from affecting the normal operation of subsequent circuits, making the input voltage more stable, thereby improving the conversion efficiency and output accuracy of the transformer and rectifier module and enhancing the overall anti-interference ability of the power supply circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 This is a module connection diagram of a power supply circuit provided in an embodiment of the present application;

[0051] Figure 2 is a circuit schematic diagram of a power supply circuit provided in an embodiment of the present application;

[0052] Figure 3This is a module connection diagram of another power supply circuit provided in an embodiment of the present application;

[0053] Figure 4 This is a circuit schematic diagram of the noise voltage suppression module provided in an embodiment of the present application. DETAILED DESCRIPTION

[0054] In order to enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this specification will be clearly and completely described below in conjunction with the drawings in the embodiments of this specification. Obviously, the described embodiments are only part of the embodiments of this application, not all of the embodiments.

[0055] In the description of the embodiments of this application, words such as "for example" or "for instance" are used to indicate examples, illustrations, or explanations. Any embodiment or design described as "for example" or "for instance" in the embodiments of this application should not be construed as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "for example" or "for instance" is intended to present the relevant concepts in a concrete manner.

[0056] In the description of the embodiments of the present application, the term "multiple" means two or more. For example, multiple systems refer to two or more systems, and multiple screen terminals refer to two or more screen terminals. In addition, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized.

[0057] The present invention will be described in more detail below with reference to the accompanying drawings. In each of the accompanying drawings, identical elements are represented by similar reference numerals. For the sake of clarity, the various parts in the accompanying drawings are not drawn to scale. In addition, some well-known parts may not be shown in the drawings.

[0058] Reference Figure 1 , which is a module connection diagram of the power supply circuit provided in an embodiment of the present application, including a transformer and rectifier module 1, a first feedback module 2 and a control module 3, wherein the first feedback module 2 is connected to the output end of the transformer and rectifier module 1, and the control module 3 is connected to the first feedback module 2 and the transformer and rectifier module 1 respectively.

[0059] The transformer and rectifier module 1 is used to receive an input voltage signal and perform rectification and voltage transformation on the input voltage signal to obtain a transformed voltage signal.

[0060] The first feedback module 2 is used to obtain the variable voltage signal and the reference output voltage signal, and generate a first feedback signal based on the variable voltage signal and the reference output voltage signal, wherein the first feedback signal is used to express the magnitude relationship between the variable voltage signal and the reference output voltage signal;

[0061] The control module 3 is configured to receive the first feedback signal and generate a first control signal according to the first feedback signal;

[0062] The transformer and rectifier module 1 is further configured to receive a first control signal and control the conduction of a switch device in the power supply circuit according to the first control signal to reduce the difference between the transformed voltage signal and the reference output voltage signal.

[0063] The first feedback module 2 is connected to the transformer and rectifier module 1 and is used to detect the magnitude relationship between the transformed voltage and the reference output voltage and generate a first feedback signal that represents this magnitude relationship. The control module 3 is connected to the first feedback module 2 and the transformer and rectifier module 1 and is used to control the conduction of the switching devices in the power supply circuit based on the first feedback signal to achieve voltage fluctuations.

[0064] Specifically, the transformer-rectifier module 1 receives an input voltage signal Vi and converts it into a variable voltage signal Vo. The output voltage Vo provided by the transformer-rectifier module satisfies current and power limiting requirements. The first feedback module 2 monitors the relationship between the variable voltage signal Vo and the reference voltage signal Vs in real time. If Vo is greater than Vs, the first feedback signal assumes one logic level; otherwise, it assumes another logic level. Upon receiving the first feedback signal, the control module 3 determines whether the transformer output voltage signal Vo is greater than the reference output voltage Vr.

[0065] Furthermore, control module 3 collects Vi, Vo, and Vr, and based on the relationship between them, calculates and generates a corresponding first control signal to control the conduction of the switching device, thereby stabilizing the variable voltage Vo as close to Vr as possible. If Vo is too high, the control signal increases the off-time of the switching device in the circuit; if Vo is too low, the control signal increases the on-time of the switching device in the circuit. Through this closed-loop control, the voltage output is achieved.

[0066] Based on the above embodiment, as an optional embodiment, Figure 2 As shown, Figure 2 A schematic diagram of a power supply circuit is shown. The transformer-rectifier module 1 may include a transformer and a synchronous rectifier unit. The second input and second output terminals of the transformer are respectively connected to the control module 3, and the three output terminals of the transformer are connected to the input and output terminals of the synchronous rectifier unit. The first input terminal of the transformer is used to receive an input voltage signal; the second output terminal of the transformer is used to output a variable voltage signal.

[0067] About the transformer-rectifier module 1: The transformer-rectifier module 1 includes a transformer and a synchronous rectification unit, wherein the transformer has two primary windings and three secondary windings, with the primary windings serving as input terminals and the secondary windings serving as output terminals, that is, the transformer has two input terminals and three output terminals. One input terminal of the transformer is used to receive an input voltage signal, and the other terminal is connected to the control module 3 for receiving a first control signal, while the synchronous rectification unit includes a synchronous rectification chip and a rectification switch tube, which is connected to the third output terminal of the transformer and is used to rectify the voltage converted and output by the transformer according to the drive signal Vg, and the drive signal Vg is provided by the synchronous rectification chip. The first end of the synchronous rectification chip is connected to one end of the rectification switch tube, and the other end of the rectification switch tube is connected to the third output terminal of the transformer. The synchronous rectifier chip detects the voltage output by the transformer using a detection circuit. When the synchronous rectifier chip detects the voltage output by the transformer, it outputs a drive signal Vg to turn on the rectifier switch tube. The switch tube can be a MOS tube, or other switch control device such as a triode or IGBT. The synchronous rectifier chip can be a TEA2095T or other rectifier controller. In addition, to determine the accuracy of the first control signal, the embodiment of the present application also has the following design:

[0068] The transformer and rectifier module 1 also includes: an auxiliary winding LK, a first MOSFET M1, a first diode D1, and a first transistor Q1; one end of the auxiliary winding LK is connected to the first input end of the transformer, the other end of the auxiliary winding LK is connected to the collector of the first transistor Q1, the base of the first transistor Q1 is connected to the control module 3, the emitter of the first transistor Q1 is connected to the cathode of the first diode D1, and the anode of the first diode D1 is connected to the connection between the control module 3 and the first transistor Q1; the gate of the first MOSFET M1 is connected to the connection between the control module 3, the first transistor Q1, and the first diode D1, the source of the first MOSFET M1 is connected to the connection between the first transistor Q1 and the auxiliary winding LK; the drain of the first MOSFET M1 is used to receive the input voltage signal.

[0069] Furthermore, the embodiment of the present application has the following design: the transformer and rectifier module 1 also includes a second MOSFET M2, a second diode D2 and a second transistor Q2; the other end of the auxiliary winding LK is connected to the drain of the second MOSFET M2, the gate of the second MOSFET M2 is connected to the emitter of the second transistor Q2, the base of the second transistor Q2 is connected to the control module 3, and the source of the second MOSFET M2 and the collector of the second transistor Q2 are grounded; the anode of the second diode D2 is connected to the connection between the second transistor Q2 and the control module 3, and the cathode of the second diode D2 is connected to the connection between the second MOSFET M2 and the second transistor Q2.

[0070] Regarding control module 3: This includes a control chip with a detection input. This chip controls the on / off state of the first MOSFET M1 based on the input voltage signal output by the power supply and the rectified voltage signal output by the transformer. The control chip can be a TEA2016AAT, or other digital controller for power supplies.

[0071] Specifically, when the first MOSFET M1 is turned on, the input voltage passes through the first MOSFET M1 and the auxiliary winding LK, forming a power-on loop. At this time, the first primary winding is in the power-on loop and is in a charging state. Simultaneously, when the second MOSFET M2 is turned on, a high-side and low-side drive loop is formed. If the first MOSFET M1 is turned off, the first primary winding is not in the loop and is in a discharging state.

[0072] Furthermore, in order to eliminate the noise interference caused by the continuous conduction of the switching device and improve the stability of the input voltage, the present application also provides a circuit connection method of an embodiment, referring to Figure 3-Figure 4 , Figure 3 This is a module connection diagram of another power supply circuit provided in an embodiment of the present application. Figure 4 This is a circuit diagram of the noise voltage suppression module provided in the embodiment of the present application, combined with Figure 3-Figure 4 To explain in detail:

[0073] The power supply circuit also includes: a noise voltage suppression module; the input end of the noise voltage suppression module is connected to the external AC power, and is used to determine the voltage suppression signal according to the voltage of the AC power; the output end of the noise voltage suppression module is connected to the drain of the first MOSFET M1, and is used to determine the input voltage signal according to the voltage suppression signal.

[0074] About the noise voltage suppression module: The noise voltage suppression module includes a number of common-mode inductors, capacitors, and resistors. The external AC power passes through the fuse and is connected in parallel with the three common-mode inductors, and then connected to the rectifier bridge formed by four diodes, and then connected to the first MOSFET M1. The output of the input voltage signal entering the first MOSFET M1, that is, the first voltage end of the three-phase power is connected to one end of the fuse, the other end of the fuse is connected to the first end of the first common-mode inductor LF1, and the third end of the first common-mode inductor LF1 is connected to the second common-mode inductor LF1. The first end of the first common-mode inductor LF1 is connected to the first end of the second common-mode inductor LF2, the third end of the second common-mode inductor LF2 is connected to the first end of the third common-mode inductor, and the third end of the third common-mode inductor is connected to the drain of the first MOSFET M1. The third voltage terminal of the three-phase power is connected to the second end of the first common-mode inductor LF1, the fourth end of the first common-mode inductor LF1 is connected to the second end of the second common-mode inductor LF2, the fourth end of the second common-mode inductor LF2 is connected to the second end of the third common-mode inductor, and the fourth end of the third common-mode inductor is connected to the drain of the first MOSFET M1. The connection between the first common-mode inductor LF1 and the second common-mode inductor LF2 is connected to a first capacitor CX1, and the connection between the second common-mode inductor LF2 and the third common-mode inductor is connected to a second capacitor CX3 and a set of resistors connected in parallel.

[0075] Specifically, since the uninterrupted on and off of the switching devices during the operation of the power supply circuit will cause common-mode noise voltage to be generated in the circuit, if the common-mode noise voltage is not eliminated, it will affect the stability of the output voltage of the power supply circuit. Therefore, the common-mode suppression module performs voltage suppression based on the external AC power. The inductor and resistor can filter out the differential-mode signal of the AC power. The common-mode inductor can effectively filter out the common-mode signal in the AC power, thereby effectively filtering out the interference signals generated by the common mode and differential mode in the AC power, outputting a high-precision input voltage signal, and improving the overall anti-interference ability of the power supply circuit.

[0076] In a feasible implementation, the control module 3 includes:

[0077] a comparator connected to the first feedback module 2, configured to receive the first feedback signal and determine, based on the first feedback signal, whether the voltage value of the variable voltage signal is greater than the voltage value of the reference output voltage signal;

[0078] The processor is connected to the comparator and is used to obtain the input voltage signal, the variable voltage signal and the reference output voltage signal when the voltage value of the variable voltage signal is greater than the voltage value of the reference output voltage signal, and generate a first control signal based on the input voltage signal, the variable voltage signal and the reference output voltage signal.

[0079] Specifically, setting up a first feedback module 2 can further improve the accuracy of voltage control. The first feedback module 2 detects the error between the variable voltage signal Vo and the reference output voltage signal Vr in real time, generates a first feedback signal and feeds it back to the control module 3. The comparator in the control module 3 is connected to the first feedback module 2, and can compare the voltage value of the received variable voltage signal with the reference output voltage to determine whether the variable voltage signal is greater than the reference output voltage signal.

[0080] Furthermore, when the comparator detects that the variable voltage signal is greater than the reference output voltage signal, it notifies the processor, which then obtains the input voltage Vi, the variable voltage Vo, and the set reference output voltage Vr. Based on the relationship between Vi, Vo, and Vr, the processor calculates and generates a first control signal, which is sent to the transformer-rectifier module 1. This precisely controls the on and off switching of the internal MOSFETs, thereby obtaining a stable output voltage and achieving a stable voltage output.

[0081] Based on the above embodiment, as an optional embodiment, the processor is used to determine the boost ratio and the buck ratio based on the input voltage signal and the variable voltage signal; if the boost ratio is greater than or equal to the buck ratio, then according to the variable voltage signal, the reference output voltage signal and the boost and buck ratios, it is determined to perform buck control on the input voltage signal; if the boost ratio is less than the buck ratio, then according to the variable voltage signal, the reference output voltage signal and the boost and buck ratios, it is determined to perform boost control on the input voltage signal.

[0082] Specifically, when it is detected that the variable voltage signal is greater than the reference output voltage signal, it means that the voltage output by the transformer is not the required voltage. At this time, in order to obtain the required voltage, the transformer and rectifier module 1 needs to be regulated. The processor calculates the corresponding boost ratio and buck ratio based on the input voltage Vi and the output voltage Vo. This is because the size relationship between Vi and Vo determines the degree to which the voltage needs to be boosted or bucked. Then, the processor compares the size relationship between the boost ratio and the buck ratio. If it is detected that the boost ratio is greater than the buck ratio at this time, it means that more bucking is needed to reduce the output voltage. In this case, it means that the current input voltage is already high and does not need to be further increased. Instead, it should be reduced to an appropriate level to avoid excessive output voltage causing equipment damage or other adverse effects.

[0083] Based on the above embodiment, as an optional embodiment, the processor is used to determine the maximum and minimum values ​​of the variable voltage signal based on the variable voltage signal; determine the new boost ratio based on the maximum and minimum values ​​of the variable voltage signal, the boost and the reference output voltage signal respectively; and generate a first control signal based on the new boost ratio.

[0084] Optionally, the processor is configured to determine a new boost duration and a new buck duration according to the new boost ratio; and generate a first control signal according to the boost duration and the buck duration.

[0085] Specifically, the processor calculates a new boost ratio based on the maximum and minimum values ​​of the variable voltage signal, the boost ratio and the reference output voltage signal, thereby obtaining a new duty cycle, and generates a first control signal, thereby controlling the opening and closing of the switching device in the transformer rectifier module 1 according to the duty cycle to achieve the purpose of regulating the output voltage.

[0086] For example, a higher duty cycle in a boost mode results in a correspondingly longer duration. Duty cycle and duration are directly proportional. Duration determines the actual operating time of each mode. The processor precisely controls the switching of the switching device according to the calculated duration, thereby regulating the output voltage.

[0087] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present application, and should all be included in the scope of protection of the present application.

Claims

1. A power supply circuit, characterized in that: include: The transformer and rectifier module is used to receive an input voltage signal and perform rectification and voltage transformation on the input voltage signal to obtain a transformed voltage signal; a first feedback module, connected to the output end of the transformer and rectifier module, configured to obtain the transformed voltage signal and a reference output voltage signal, and generate a first feedback signal based on the transformed voltage signal and the reference output voltage signal, wherein the first feedback signal is used to express a magnitude relationship between the transformed voltage signal and the reference output voltage signal; a control module, connected to the first feedback module and the transformer and rectifier module respectively, configured to receive the first feedback signal and generate a first control signal according to the first feedback signal; The transformer and rectifier module is further configured to receive the first control signal and control the conduction of the switch device according to the first control signal to reduce the difference between the transformed voltage signal and the reference output voltage signal; Wherein, the control module includes: a comparator, connected to the first feedback module, configured to receive the first feedback signal and determine, based on the first feedback signal, whether the voltage value of the variable voltage signal is greater than the voltage value of the reference output voltage signal; a processor connected to the comparator, configured to obtain the input voltage signal, the variable voltage signal, and the reference output voltage signal when the voltage value of the variable voltage signal is greater than the voltage value of the reference output voltage signal, and generate a first control signal based on the input voltage signal, the variable voltage signal, and the reference output voltage signal; The processor is configured to: Determining a voltage step-up ratio and a voltage step-down ratio according to the input voltage signal and the variable voltage signal; If the boost ratio is greater than or equal to the buck ratio, determining to perform buck control on the input voltage signal according to the variable voltage signal, the reference output voltage signal, and the boost ratio and the buck ratio; If the boost ratio is less than the buck ratio, determining to perform boost control on the input voltage signal according to the variable voltage signal, the reference output voltage signal, and the boost ratio and the buck ratio; The transformer and rectifier module includes a transformer and a synchronous rectifier unit; The second input terminal and the second output terminal of the transformer are connected to the control module respectively, and the third output terminal of the transformer is connected to the input terminal of the synchronous rectification unit; The first input end of the transformer is used to receive the input voltage signal; the second output end of the transformer is used to output a transformed voltage signal.

2. The power supply circuit according to claim 1, wherein: The processor is configured to: Determining a maximum value and a minimum value of the variable voltage signal according to the variable voltage signal; determining a new boost ratio according to the maximum value and the minimum value of the variable voltage signal, the boost ratio, and the reference output voltage signal; The first control signal is generated according to the new boost ratio.

3. The power supply circuit according to claim 2, wherein: The processor is configured to: Determining a new boost duration and a new buck duration within a preset time period according to the new boost ratio; The first control signal is generated according to the boost duration and the buck duration.

4. The power supply circuit according to claim 1, wherein: The transformer and rectifier module further includes: an auxiliary winding, a first MOS tube, a first diode and a first transistor; One end of the auxiliary winding is connected to the first input end of the transformer, the other end of the auxiliary winding is connected to the collector of the first transistor, the base of the first transistor is connected to the control module, the emitter of the first transistor is connected to the cathode of the first diode, and the anode of the first diode is connected to the connection between the control module and the first transistor; The connection point between the control module, the first transistor and the first diode is connected to the gate of the first MOSFET, and the source of the first MOSFET is connected to the connection point between the first transistor and the auxiliary winding; The drain of the first MOS tube is used to receive the input voltage signal.

5. The power supply circuit according to claim 4, wherein: The transformer and rectifier module further includes a second MOS tube, a second diode and a second transistor; The other end of the auxiliary winding is connected to the drain of the second MOSFET, the gate of the second MOSFET is connected to the emitter of the second transistor, the base of the second transistor is connected to the control module, and the source of the second MOSFET and the collector of the second transistor are grounded; The anode of the second diode is connected to the connection between the second transistor and the control module, and the connection between the gate of the second MOS tube and the emitter of the second transistor is connected to the cathode of the second diode.

6. The power supply circuit according to claim 4, wherein: The power supply circuit further includes: a noise voltage suppression module; The input end of the noise voltage suppression module is connected to the external alternating current, and is used to determine the voltage suppression signal according to the voltage of the alternating current. The output end of the noise voltage suppression module is connected to the drain of the first MOS tube, and is used to determine the input voltage signal according to the voltage suppression signal.

7. A power adapter, characterized in that: The method comprises the power supply circuit according to any one of claims 1 to 6.

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