Buck-boost circuit and control method thereof, chip and electronic equipment

Abstract

A buck-boost circuit, a control method thereof, a chip and an electronic device belong to the technical field of electronic circuits, and the buck-boost circuit is provided with a first end, a second end and a third end; the first end and the second end form a first input / output end, and the second end and the third end form a second input / output end; in a charging mode, the buck-boost circuit stores electric energy at a first phase of a charging period according to first charging direct current input by the first input and output end, and outputs second charging direct current from the second input and output end based on the stored electric energy at a second phase of the charging period; in the discharging mode, the buck-boost circuit stores electric energy at a first phase of a discharging period according to first discharging direct current input by the second input and output end, and outputs second discharging direct current from the first input and output end based on the stored electric energy at a second phase of the discharging period. In the charging and discharging process, a straight-through path does not occur, the battery overcharge under the input and output straight-through condition when the bridge arm is short-circuited in the full-bridge topology is avoided, and the reliability is improved.

Description

Technical Field

[0001] The present application belongs to the field of electronic circuit technology, and in particular, relates to a buck-boost circuit and a control method thereof, a chip, and an electronic device. Background Art

[0002] At present, the buck-boost power management chip using fast charging protocols such as quickcharge (QC) or USB power delivery (PD) often encounters the situation that the voltage at the power supply end is greater than, equal to or less than the voltage of the receiving device during operation. In the face of a wide range of voltage input conditions, the full-bridge buck-boost topology is mainly used to implement a synchronous bidirectional buck-boost controller, which can achieve boost or buck charging management when the input voltage is higher or lower than the output voltage. When the system uses the battery pack to discharge externally, the full-bridge buck-boost topology can output current in reverse, and can output a voltage lower or higher than the battery pack. The synchronous full-bridge bidirectional buck-boost controller performs better in terms of energy feedback and energy loss, greatly improving the energy utilization of the system.

[0003] The full-bridge topology is currently widely used in market applications to achieve BUCK / BOOST multi-mode operation. In the full-bridge topology, during the charging process, during the boost or buck process, one side of the power tube is always open, and the other side of the power tube is used as a switch. Once the bridge arm is short-circuited, it will cause the input and output to pass directly, which is very easy to cause battery overcharging.

[0004] Therefore, the reliability of the related step-up and step-down circuits is poor. Summary of the invention

[0005] The purpose of the present application is to provide a buck-boost circuit and a control method, chip, and electronic device thereof, aiming to solve the problem of poor reliability of related buck-boost circuits.

[0006] The embodiment of the present application provides a buck-boost circuit, comprising a first end, a second end and a third end; wherein the first end and the second end constitute a first input-output end of the buck-boost circuit, and the second end and the third end constitute a second input-output end of the buck-boost circuit;

[0007] In the charging mode, the buck-boost circuit is configured to store electric energy according to the first charging direct current inputted from the first input-output terminal in a first phase of the charging cycle, and output a second charging direct current from the second input-output terminal based on the stored electric energy in a second phase of the charging cycle;

[0008] In the discharge mode, the buck-boost circuit is further configured to store electric energy according to the first discharge direct current inputted from the second input-output terminal in a first phase of the discharge cycle, and output a second discharge direct current from the first input-output terminal based on the stored electric energy in a second phase of the discharge cycle;

[0009] The charging cycle and the discharging cycle each include two cycle intervals, and each cycle interval corresponds to the first phase and the second phase one by one.

[0010] In one embodiment, the first input-output terminal is connected to a charging circuit, and the second input-output terminal is connected to a first energy storage circuit;

[0011] The charging circuit is configured to output the first charging direct current;

[0012] The first energy storage circuit is configured to be charged based on the second charging direct current.

[0013] In one embodiment, the first input-output terminal is connected to the power receiving circuit, and the second input-output terminal is connected to the second energy storage circuit;

[0014] The second energy storage circuit is configured to output the first discharge direct current;

[0015] The power receiving circuit is configured to operate based on the second discharged direct current.

[0016] In one embodiment, the buck-boost circuit includes a first power tube, a second power tube and an inductor;

[0017] The drain of the first power tube serves as the first end of the buck-boost circuit, the source of the first power tube is connected to the drain of the second power tube and the first end of the inductor, the second end of the inductor serves as the second end of the buck-boost circuit, and the source of the second power tube serves as the third end of the buck-boost circuit;

[0018] The gate of the first power tube serves as the first control terminal of the buck-boost circuit to receive a first control signal;

[0019] The gate of the second power tube serves as the second control terminal of the buck-boost circuit to receive a second control signal;

[0020] Wherein, at the same time, at most one of the first power tube and the second power tube is turned on.

[0021] In one embodiment, in a first phase of a charging cycle, the first power tube is turned on and the second power tube is turned off;

[0022] In the second phase of the charging cycle, the first power tube is turned off and the second power tube is turned on.

[0023] In one embodiment, in a first phase of a discharge cycle, the first power tube is turned off and the second power tube is turned on;

[0024] In the second phase of the discharge cycle, the first power tube is turned on and the second power tube is turned off.

[0025] An embodiment of the present invention further provides an electronic device, wherein the electronic device includes the above-mentioned buck-boost circuit.

[0026] An embodiment of the present invention further provides a chip, wherein the chip includes the above-mentioned buck-boost circuit.

[0027] An embodiment of the present invention further provides a control method for a buck-boost circuit. Based on the buck-boost circuit described above, the control method includes:

[0028] Step A1: connecting the first input / output terminal to the charging circuit, and connecting the second input / output terminal to the first energy storage circuit;

[0029] Step B1: controlling the first power tube to be turned on, and controlling the second power tube to be turned off;

[0030] Step C1: control the first power tube to be turned off, and control the second power tube to be turned on, and repeat steps B1 and C1 in sequence.

[0031] An embodiment of the present invention further provides a control method for a buck-boost circuit. Based on the buck-boost circuit described above, the control method includes:

[0032] Step A2: connecting the first input / output terminal and the power receiving circuit, and connecting the second input / output terminal and the first energy storage circuit;

[0033] Step B2: Control the first power tube to be turned off, and control the second power tube to be turned on;

[0034] Step C2: control the first power tube to be turned on, and control the second power tube to be turned off, and repeat steps B2 and C2 in sequence.

[0035] Compared with the prior art, the embodiments of the present invention have the following beneficial effects: in the charging mode, the buck-boost circuit stores electric energy according to the first charging direct current inputted from the first input-output terminal in the first phase of the charging cycle, and outputs the second charging direct current from the second input-output terminal based on the stored electric energy in the second phase of the charging cycle; in the discharging mode, the buck-boost circuit stores electric energy according to the first discharging direct current inputted from the second input-output terminal in the first phase of the discharging cycle, and outputs the second discharging direct current from the first input-output terminal based on the stored electric energy in the second phase of the discharging cycle; and the charging cycle and the discharging cycle both include two cycle intervals, and each cycle interval corresponds one-to-one to the first phase and the second phase; therefore, in the first phase and the second phase, at most one of the first input-output terminal and the second input-output terminal conducts direct current, that is, no direct path will appear during the charging process or the discharging process, and at the same time, the defect of battery overcharging in the case of direct input and output when the bridge arm is short-circuited in the full-bridge scheme is avoided, thereby improving reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical invention in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0037] Figure 1 A schematic diagram of a structure of a buck-boost circuit provided in one embodiment of the present application;

[0038] Figure 2 Another structural schematic diagram of a buck-boost circuit provided in an embodiment of the present application;

[0039] Figure 3 Another structural schematic diagram of a buck-boost circuit provided in an embodiment of the present application;

[0040] Figure 4 A partial exemplary circuit schematic diagram of a buck-boost circuit provided in an embodiment of the present application;

[0041] Figure 5 Another partial exemplary circuit schematic diagram of a buck-boost circuit provided in an embodiment of the present application;

[0042] Figure 6 Another partial exemplary circuit schematic diagram of a buck-boost circuit provided in an embodiment of the present application. DETAILED DESCRIPTION

[0043] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0044] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0045] It should be understood that the orientation or position relationship indicated by terms such as "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0046] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0047] Figure 1 The schematic diagram of the structure of the buck-boost circuit provided by the preferred embodiment of the present application is shown. For the convenience of explanation, only the part related to the present embodiment is shown, which is described in detail as follows:

[0048] The buck-boost circuit 10 has a first terminal A1, a second terminal A2 and a third terminal A3; wherein the first terminal A1 and the second terminal A2 constitute a first input-output terminal of the buck-boost circuit 10, and the second terminal A2 and the third terminal A3 constitute a second input-output terminal of the buck-boost circuit 10.

[0049] In the charging mode, the buck-boost circuit 10 is configured to store electrical energy according to the first charging DC power input from the first input / output terminal in a first phase of the charging cycle, and to output a second charging DC power from the second input / output terminal based on the stored electrical energy in a second phase of the charging cycle.

[0050] In the discharge mode, the buck-boost circuit 10 is also configured to store electrical energy according to the first discharge DC power input from the second input / output terminal in the first phase of the discharge cycle, and to output the second discharge DC power from the first input / output terminal based on the stored electrical energy in the second phase of the discharge cycle.

[0051] The charging cycle and the discharging cycle each include two cycle intervals, and each cycle interval corresponds one-to-one to the first phase and the second phase.

[0052] It should be noted that the duration ratio of the first phase of the charging cycle to the second phase of the charging cycle can be adjusted according to actual needs; the duration ratio of the first phase of the discharging cycle to the second phase of the discharging cycle can also be adjusted according to actual needs.

[0053] In one embodiment, when the quotient of the duration of the first phase of the charging cycle divided by the duration of the second phase of the charging cycle is greater than 1, the buck-boost circuit 10 operates in a boost state; when the quotient of the duration of the first phase of the charging cycle divided by the duration of the second phase of the charging cycle is less than 1, the buck-boost circuit 10 operates in a buck state.

[0054] In one embodiment, when the quotient of the duration of the first phase of the discharge cycle divided by the duration of the second phase of the discharge cycle is less than 1, the buck-boost circuit 10 operates in a boost state; when the quotient of the duration of the first phase of the discharge cycle divided by the duration of the second phase of the discharge cycle is greater than 1, the buck-boost circuit 10 operates in a buck state.

[0055] In one embodiment, in the charging mode, the first terminal A1 serves as the positive electrode of the first input / output terminal, the second terminal A2 serves as the negative electrode of the first input / output terminal, the second terminal A2 serves as the positive electrode of the second input / output terminal, and the third terminal A3 serves as the negative electrode of the second input / output terminal. In the discharging mode, the second terminal A2 serves as the positive electrode of the second input / output terminal, the third terminal A3 serves as the negative electrode of the second input / output terminal, the first terminal A1 serves as the positive electrode of the first input / output terminal, and the second terminal A2 serves as the negative electrode of the first input / output terminal.

[0056] like Figure 2 As shown, the first input-output terminal is connected to the charging circuit 20, and the second input-output terminal is connected to the first energy storage circuit 30;

[0057] The charging circuit 20 is configured to output a first charging direct current.

[0058] The first energy storage circuit 30 is configured to be charged based on the second charging DC power.

[0059] It can be understood that the charging circuit 20 is configured to output a first charging DC power, and the buck-boost circuit 10 bucks and re-boosts the first charging DC power and outputs a second charging DC power to charge the first energy storage circuit 30 .

[0060] By connecting the charging circuit 20 and the first energy storage circuit 30 , the charging circuit 20 charges the first energy storage circuit 30 .

[0061] like Figure 3 As shown, the first input-output terminal is connected to the power receiving circuit 40, and the second input-output terminal is connected to the second energy storage circuit 50;

[0062] The second energy storage circuit 50 is configured to output a first discharge direct current.

[0063] The power receiving circuit 40 is configured to operate based on the second discharged direct current.

[0064] It can be understood that the second energy storage circuit 50 outputs a first discharge DC power, and the buck-boost circuit 10 bucks and boosts the first discharge DC power and outputs a second discharge DC power to supply power to the power receiving circuit 40 .

[0065] By connecting the power receiving circuit 40 and the second energy storage circuit 50 , the second energy storage circuit 50 supplies power to the power receiving circuit 40 .

[0066] Figure 4 A partial exemplary circuit structure of a buck-boost circuit 10 provided in an embodiment of the present invention is shown. For the sake of convenience, only the part related to the embodiment of the present invention is shown, which is described in detail as follows:

[0067] The buck-boost circuit 10 includes a first power tube Q1 , a second power tube Q2 and an inductor L.

[0068] The drain of the first power tube Q1 serves as the first end A1 of the buck-boost circuit 10, the source of the first power tube Q1 is connected to the drain of the second power tube Q2 and the first end of the inductor L, the second end A2 of the inductor L serves as the second end A2 of the buck-boost circuit 10, and the source of the second power tube Q2 serves as the third end A3 of the buck-boost circuit 10; the gate of the first power tube Q1 serves as the first control end of the buck-boost circuit 10 to access the first control signal; the gate of the second power tube Q2 serves as the second control end of the buck-boost circuit 10 to access the second control signal.

[0069] At the same time, at most one of the first power tube Q1 and the second power tube Q2 is turned on.

[0070] The full-bridge topology includes four switch tubes. Whether the switch tubes are external or internal, the application cost is relatively high. In addition, facing complex application environments such as bidirectional DC-DC (Direct Current-Direct Current, DCDC) boost, buck, and buck-boost, the overall switch tube control timing and logic are relatively complex, and higher requirements are placed on system logic design and reliability. When the battery is discharging, especially when there are multiple outputs, two back-to-back switch tubes are required at the output port to prevent the problem of current backflow. Therefore, the buck-boost circuit 10 using the full-bridge topology structure, on the one hand, has a complex chip circuit design, and the overall complex application environment further increases the complexity of the printed circuit board, which puts forward certain requirements for the overall design reliability. On the other hand, due to the full-bridge structure, the cost of the overall solution is bound to increase.

[0071] The buck-boost circuit 10 structure of the application has the following advantages: First, only two switch tubes (power tubes) are needed to realize the bidirectional buck-boost scheme. Compared with the full-bridge topology, it not only simplifies the circuit complexity, but also reduces the overall printed circuit board area (or chip layout area) and cost. In the full-bridge topology, the control timing logic of the four switch tubes is relatively complex for different input and output conditions, while the two switch tubes have the advantage of simple timing logic in terms of logic control. Second, in the case of multi-port output, for the port control switch tube, when multiple outputs are output, each output path only needs a single switch tube. Third, during the charging process of the battery pack, for the full-bridge charging process, once the bridge arm short circuit fails, the input end and the output end are directly connected, which can easily lead to overcharging of the battery. In the half-bridge charging process, there will be no direct path when the bridge arm is short-circuited, and the problem of battery overcharging when the bridge arm is short-circuited is avoided. However, since the input and output are in series, the withstand voltage capability is higher than that of the full-bridge topology. When applied to the chip, it can simplify the circuit design, reduce costs, and enhance the ability to resist external failures.

[0072] The following is a combination of working principles Figure 4 As shown for further explanation:

[0073] It should be emphasized that the buck-boost circuit 10 can operate in a charging mode and a discharging mode.

[0074] In the charging mode, in the first phase of the charging cycle, the first power tube Q1 is turned on and the second power tube Q2 is turned off; in the second phase of the charging cycle, the first power tube Q1 is turned off and the second power tube Q2 is turned on.

[0075] At this time, if Figure 5As shown, the first input and output end is used as an input end and can be connected to the charging circuit 20; the second input and output end is used as an output end and can be connected to the first energy storage circuit 30; thereby charging the first energy storage circuit 30; at this time, the buck-boost circuit 10 is a BUCK topology structure. During the charging process, when the first power tube Q1 works in the on state and the second power tube Q2 works in the off state, the first power tube Q1 is turned on, and the first charging DC charges the inductor L through the first power tube Q1, the inductor current increases linearly, and the electric energy is stored in the inductor in the form of magnetic field energy; when the first power tube Q1 is turned off and the second power tube Q2 is turned on, the inductor current continues to flow through Q2, the inductor current decreases linearly, the inductor releases energy, and the energy is transferred to the second input and output end, thereby charging the first energy storage circuit 30. The voltage VCC1 of the first charging DC and the voltage VDD1 of the second charging DC satisfy the following relationship. By setting the duty cycle D1 of the switch tube Q1 in the charging cycle, the charging buck-boost mode can be realized.

[0076]

[0077] In the discharge mode, in the first phase of the discharge cycle, the first power tube Q1 is turned off and the second power tube Q2 is turned on; in the second phase of the discharge cycle, the first power tube Q1 is turned on and the second power tube Q2 is turned off.

[0078] At this time, if Figure 6 As shown, the first input and output end is used as the output end and connected to the power receiving circuit 40; the second input and output end is used as the input end and connected to the second energy storage circuit 50 to discharge the power receiving circuit 40; the buck-boost module is a BOOST topology structure. During the discharge process, when the second power tube Q2 is turned on and the first power tube Q1 is turned off, the voltage VCC2 of the first discharge DC power is applied to both ends of the inductor L, the inductor current increases linearly, the battery pack charges the inductor L, the inductor stores energy, and the electric energy is stored in the inductor in the form of magnetic field energy. When the second power tube Q2 is turned off, the first power tube Q1 is turned on, and the inductor L discharges to the first input and output end through the first power tube Q1, completing the discharge process of the power receiving circuit 40. The voltage VDD2 of the second discharge DC power and the voltage VCC2 of the first discharge DC power satisfy the following relationship. By setting the duty cycle D2 of the first power tube Q1 in the discharge cycle, the discharge buck-boost mode can be realized.

[0079]

[0080] An embodiment of the present invention further provides an electronic device, which includes the above-mentioned buck-boost circuit.

[0081] An embodiment of the present invention further provides a chip, which includes the above-mentioned buck-boost circuit.

[0082] The present invention also provides a control method for a buck-boost circuit, characterized in that, based on the above buck-boost circuit, the control method includes A1 to C1.

[0083] Step A1: Connect the first input-output terminal and the charging circuit, and connect the second input-output terminal and the first energy storage circuit.

[0084] Step B1: Control the first power transistor Q1 to conduct, and control the second power transistor Q2 to turn off.

[0085] In step B1, the first charging direct current charges the inductor L through the first power transistor Q1, the inductor current increases linearly, and the electrical energy is stored in the inductor in the form of magnetic field energy.

[0086] Step C1: Control the first power transistor Q1 to turn off, and control the second power transistor Q2 to conduct, and sequentially repeat steps B1 and C1.

[0087] In step C1, the inductor current freewheels through the second power transistor Q2, the inductor current decreases linearly, the inductor releases energy, and the energy is transferred to the second input-output terminal and outputs the second charging direct current.

[0088] It can be understood that by regulating the duty cycle D1 of the first power transistor Q1 in the entire charging cycle, when 0% < D1 < 50%, the buck-boost circuit steps down from the first input-output terminal to the second input-output terminal; by regulating the duty cycle D1 of the first power transistor Q1 in the charging cycle, when 50% < D1 < 100%, the buck-boost circuit steps up from the first input-output terminal to the second input-output terminal.

[0089] The present invention also provides another control method for a buck-boost circuit, characterized in that, based on the above buck-boost circuit, the control method includes A2 to C2.

[0090] Step A2: Connect the first input-output terminal and the power receiving circuit, and connect the second input-output terminal and the first energy storage circuit.

[0091] Step B2: Control the first power transistor Q1 to turn off, and control the second power transistor Q2 to conduct.

[0092] In step B2, the voltage VCC2 of the first discharge direct current is applied across the inductor L, the inductor current increases linearly, the battery pack charges the inductor L, and the inductor stores energy, and the electrical energy is stored in the inductor in the form of magnetic field energy.

[0093] Step C2: Control the first power transistor Q1 to conduct, and control the second power transistor Q2 to turn off, and sequentially repeat steps B2 and C2.

[0094] In step C2, the inductor current freewheels through the first power transistor Q1, the inductor current linearly decreases, the inductor releases energy, and the energy is transferred to the first input / output terminal and a second discharge direct current is output.

[0095] It can be understood that by regulating the duty cycle D1 of the first power transistor Q1 during the entire discharge cycle, when 0% < D1 < 50%, the buck-boost circuit boosts the voltage from the second input / output terminal to the first input / output terminal; by regulating the duty cycle D1 of the first power transistor Q1 during the charging cycle, when 50% < D1 < 100%, the buck-boost circuit steps down the voltage from the second input / output terminal to the first input / output terminal.

[0096] It should be understood that the magnitudes of the sequence numbers of the steps in the above embodiments do not imply the order of execution. The order of execution of each process should be determined by its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.

[0097] 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 foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included within the protection scope of the present application.

Claims

1. A step-up / step-down circuit, characterized in that: It has a first end, a second end and a third end; wherein the first end and the second end constitute the first input-output end of the buck-boost circuit, and the second end and the third end constitute the second input-output end of the buck-boost circuit; In the charging mode, the buck-boost circuit is configured to store electric energy according to the first charging direct current inputted from the first input-output terminal in a first phase of the charging cycle, and output a second charging direct current from the second input-output terminal based on the stored electric energy in a second phase of the charging cycle; In the discharge mode, the buck-boost circuit is further configured to store electric energy according to the first discharge direct current inputted from the second input-output terminal in a first phase of the discharge cycle, and output a second discharge direct current from the first input-output terminal based on the stored electric energy in a second phase of the discharge cycle; The charging cycle and the discharging cycle each include two cycle intervals, and each cycle interval corresponds to the first phase and the second phase one by one.

2. The step-up / down voltage circuit according to claim 1, wherein: The first input-output terminal is connected to the charging circuit, and the second input-output terminal is connected to the first energy storage circuit; The charging circuit is configured to output the first charging direct current; The first energy storage circuit is configured to be charged based on the second charging direct current.

3. The step-up / down voltage circuit according to claim 1, wherein: The first input-output terminal is connected to the power receiving circuit, and the second input-output terminal is connected to the second energy storage circuit; The second energy storage circuit is configured to output the first discharge direct current; The power receiving circuit is configured to operate based on the second discharged direct current.

4. The step-up / down voltage circuit according to claim 1, wherein: The buck-boost circuit includes a first power tube, a second power tube and an inductor; The drain of the first power tube serves as the first end of the buck-boost circuit, the source of the first power tube is connected to the drain of the second power tube and the first end of the inductor, the second end of the inductor serves as the second end of the buck-boost circuit, and the source of the second power tube serves as the third end of the buck-boost circuit; The gate of the first power tube serves as the first control terminal of the buck-boost circuit to receive a first control signal; The gate of the second power tube serves as the second control terminal of the buck-boost circuit to receive a second control signal; Wherein, at the same time, at most one of the first power tube and the second power tube is turned on.

5. The step-up / down voltage circuit according to claim 4, characterized in that: In the first phase of the charging cycle, the first power tube is turned on and the second power tube is turned off; In the second phase of the charging cycle, the first power tube is turned off and the second power tube is turned on.

6. The step-up / down voltage circuit according to claim 4, wherein: In the first phase of the discharge cycle, the first power tube is turned off and the second power tube is turned on; In the second phase of the discharge cycle, the first power tube is turned on and the second power tube is turned off.

7. An electronic device, characterized in that: The electronic device comprises the buck-boost circuit according to any one of claims 1 to 6.

8. A chip, characterized in that: The chip includes the buck-boost circuit as described in any one of claims 1 to 6.

9. A control method for a buck-boost circuit, characterized in that: Based on the buck-boost circuit according to any one of claims 4 to 6, the control method comprises: Step A1: connecting the first input / output terminal to the charging circuit, and connecting the second input / output terminal to the first energy storage circuit; Step B1: controlling the first power tube to be turned on, and controlling the second power tube to be turned off; Step C1: control the first power tube to be turned off, and control the second power tube to be turned on, and repeat steps B1 and C1 in sequence.

10. A control method for a buck-boost circuit, characterized in that: Based on the buck-boost circuit according to any one of claims 4 to 6, the control method comprises: Step A2: connecting the first input / output terminal and the power receiving circuit, and connecting the second input / output terminal and the first energy storage circuit; Step B2: Control the first power tube to be turned off, and control the second power tube to be turned on; Step C2: control the first power tube to be turned on, and control the second power tube to be turned off, and repeat steps B2 and C2 in sequence.

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