Hybrid BUCK-BOOST topological structure and control method and control device thereof

Abstract

The invention discloses a hybrid BUCK-BOOST topological structure and a control method and a control device thereof, the topological structure comprises an input voltage source, a first switch tube, a second switch tube, a third switch tube, a fourth switch tube, a fifth switch tube, a sixth switch tube, a first flying capacitor, a second flying capacitor, an output capacitor and a power inductor, PWM control is adopted, when the duty ratio is less than 0.5, the output capacitor is switched on, and the output capacitor is switched off. And when the duty ratio is larger than 0.5, the step-down operation is executed, and the step-up operation is executed. The topological structure adopts a single-mode control strategy, and compared with a traditional single-mode control four-switch hybrid BUCK-BOOST topological structure, the topological structure not only can greatly reduce inductive current, but also has the characteristic of continuous output transfer current, and can remarkably improve circuit efficiency and transient response speed.

Description

Technical Field

[0001] The present invention belongs to the technical field of integrated circuits, and particularly relates to a hybrid BUCK-BOOST topology structure, a control method thereof, and a control device thereof. Background Art

[0002] In recent years, mobile devices have been developing towards miniaturization and wearability. At the same time, the complexity of their internal functional circuits has been increasing, and the load current of the internal power management chip has increased. Since the capacity of the lithium-ion batteries equipped in these devices is limited, in order to extend the operating time of the devices, it is crucial to improve the efficiency of the internal power management chip. In addition, in order to adapt to the development of miniaturization, the power management chip should preferably use small-sized inductors, but the parasitic DC resistance of small-sized inductors is relatively large. The output voltage range of lithium-ion batteries is 2.7V to 4.2V, and voltages such as 3.3V, 1.8V, 5V, etc. can be generated by different power management integrated circuits (PMICs) to supply power to different load networks. Among them, most of the functional circuits in mobile devices use a 3.3V voltage, which is generated by a Buck-Boost converter.

[0003] Traditional four-switch Buck-Boost (CBBC) converters face challenges when applied in this scenario: First, in the single control mode, the inductor current of the CBBC is too large, and the conduction loss caused by the parasitic DC resistance of the inductor is serious, making it difficult to achieve high efficiency; Second, in the dual-mode control CBBC, the inductor current is also large during the boost operation, which is not suitable for large-load applications, and the switching between its buck and boost operations faces challenges, and a transition mode needs to be designed, and the control loop is complex. In addition, the input-output current transfer of the traditional non-inverting Buck-Boost converter (CBBC) is discontinuous, which limits the loop bandwidth and the transient response speed is limited. Summary of the Invention

[0004] In order to solve the above problems existing in the prior art, the present invention provides a hybrid BUCK-BOOST topology structure, a control method thereof, and a control device thereof. The technical problems to be solved by the present invention are achieved through the following technical solutions:

[0005] The present invention provides a hybrid BUCK-BOOST topology structure, including an input voltage source, a first switch tube S1, a second switch tube S2, a third switch tube S3, a fourth switch tube S4, a fifth switch tube S5, a sixth switch tube S6, a first flying capacitor C F1 , a second flying capacitor C F2 , an output capacitor C OUT , and a power inductor L, wherein,

[0006] The negative terminal of the input voltage source is connected to the ground terminal, and the positive terminal of the input voltage source is connected to the first terminal of the first switching transistor S1 and the first terminal of the fourth switching transistor S4. The input voltage source is used to provide an input voltage V IN ;

[0007] The second terminal of the first switching transistor S1 is connected to the upper plate of the first flying capacitor C F1 and the first terminal of the second switching transistor S2. The second terminal of the fourth switching transistor S4 is connected to the lower plate of the first flying capacitor C F1 , the first terminal of the sixth switching transistor S6, and the first terminal of the third switching transistor S3. The second terminal of the sixth switching transistor S6 is connected to the first terminal of the fifth switching transistor S5 and the lower plate of the second flying capacitor C F2 . The second terminal of the fifth switching transistor S5 is connected to the ground terminal;

[0008] The second terminal of the second switching transistor S2 is connected to the second terminal of the third switching transistor S3, the upper plate of the second flying capacitor C F2 , and the first terminal of the power inductor L. The second terminal of the power inductor L is connected to the first terminal of the load I LOAD and the upper plate of the output capacitor C OUT . The lower plate of the output capacitor C OUT is connected to the second terminal of the load I LOAD , and the second terminal of the load I LOAD is connected to the ground terminal.

[0009] In one embodiment of the present invention, the capacitance values of the first flying capacitor C F1 and the second flying capacitor C F2 are equal.

[0010] In one embodiment of the present invention, the relationship between the input voltage V IN , the output voltage V OUT and the duty cycle D is V OUT / V IN = 0.5 + D, where the output voltage V OUT is the voltage value at the second terminal of the power inductor L.

[0011] In one embodiment of the present invention, the first switching transistor S1, the second switching transistor S2, the third switching transistor S3, the fourth switching transistor S4, and the sixth switching transistor S6 are selected as switching transistors with a maximum breakdown voltage of V IN / 2, and the fifth switching transistor S5 is selected as a switching transistor with a maximum breakdown voltage of V IN .

[0012] In one embodiment of the present invention, in the buck mode and the boost mode, the current of the power inductor L is equal to the current of the load.

[0013] Another aspect of the present invention provides a control method for a hybrid BUCK - BOOST topology structure, which is used to control the hybrid BUCK - BOOST topology structure described in the above embodiment. The control method adopts a single - mode control strategy. In a switching period T, the conduction states of the first switch tube S1, the second switch tube S2, the third switch tube S3, the fourth switch tube S4, the fifth switch tube S5, and the sixth switch tube S6 of the hybrid BUCK - BOOST topology structure include a first stage and a second stage wherein,

[0014] in the first stage control the first switch tube S1, the third switch tube S3, and the fifth switch tube S5 to turn off, and the second switch tube S2, the fourth switch tube S4, and the sixth switch tube S6 to turn on;

[0015] in the second stage control the first switch tube, the third switch tube, and the fifth switch tube to turn on, and the second switch tube, the fourth switch tube, and the sixth switch tube to turn off.

[0016] In one embodiment of the present invention, the time length of the first stage is equal to the switching period T multiplied by the duty cycle D; the time length of the second stage is equal to the switching period T multiplied by (1 - D).

[0017] Another aspect of the present invention provides a control device for a hybrid BUCK - BOOST topology structure, which is used to control the hybrid BUCK - BOOST topology structure described in the above embodiment. The control device includes an error amplifier with type - III compensation, a ramp generator, a comparator, a dead - time generation circuit, a level - shifting circuit, and a Buffer. Among them,

[0018] the non - inverting input terminal and the inverting input terminal of the error amplifier with type - III compensation respectively input a reference voltage Vref and a voltage V OUT sampled and fed back from the output voltage V FB , where the reference voltage Vref is a preset constant, and the output voltage V OUT is the voltage value at the second end of the power inductor L; the output terminal of the error amplifier with type - III compensation is connected to the non - inverting input terminal of the comparator; the output terminal of the ramp generator is connected to the inverting input terminal of the comparator;

[0019] The output terminal of the comparator is connected to the input terminal of the dead time generation circuit, the output terminal of the dead time generation circuit is connected to the level shift circuit, and the output terminal of the level shift circuit is respectively connected to the control terminals of the first switch tube S1, the second switch tube S2, the third switch tube S3, the fourth switch tube S4, the fifth switch tube S5, and the sixth switch tube S6 in the hybrid BUCK-BOOST topology through corresponding Buffers.

[0020] In an embodiment of the present invention, the phase of the first control signal is the same as that of the input signal of the dead time generation circuit, and the phase of the second control signal is opposite to that of the input signal of the dead time generation circuit.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0022] 1. The hybrid BUCK-BOOST topology, its control method, and control device provided by the present invention can not only achieve seamless switching between boost and buck operations through a simple control loop, but also effectively reduce the inductor current. On the premise of ensuring high efficiency, the chip area and inductor size are greatly reduced, better meeting the miniaturization requirements of mobile devices. In addition, when the hybrid BUCK-BOOST topology works, it also has the characteristic of continuous output transfer current, which can significantly improve the circuit efficiency and transient response speed.

[0023] The following will further describe the present invention in detail with reference to the drawings and embodiments. Description of the Drawings

[0024] Figure 1 is a schematic diagram of a hybrid BUCK-BOOST topology provided by an embodiment of the present invention;

[0025] Figure 2a is Figure 1 a schematic diagram of the conduction states of each switch tube in the first stage when the shown hybrid BUCK-BOOST topology works; a schematic diagram of the conduction states of each switch tube;

[0026] Figure 2b is Figure 1 a schematic diagram of the conduction states of each switch tube in the second stage when the shown hybrid BUCK-BOOST topology works; a schematic diagram of the conduction states of each switch tube;

[0027] Figure 3 is a schematic diagram of the main waveforms of the circuit of the hybrid BUCK-BOOST topology provided by an embodiment of the present invention in and two stages;

[0028] Figure 4It is a schematic diagram of a control device for a hybrid BUCK - BOOST topology provided by an embodiment of the present invention. Detailed implementation manners

[0029] In order to further elaborate on the technical means and effects adopted by the present invention to achieve the intended invention purpose, hereinafter, in combination with the accompanying drawings and specific implementation manners, a hybrid BUCK - BOOST topology and its control method and control device proposed according to the present invention will be described in detail.

[0030] The foregoing and other technical contents, features and effects of the present invention can be clearly presented in the following detailed description in conjunction with the accompanying drawings. Through the description of the specific implementation manners, a more in - depth and specific understanding of the technical means and effects adopted by the present invention to achieve the intended purpose can be obtained. However, the attached drawings are only for reference and explanation, and are not used to limit the technical solution of the present invention.

[0031] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant is intended to cover non - exclusive inclusion, so that an article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed. Without more limitations, an element defined by the statement "including one..." does not exclude the existence of another identical element in the article or device including the said element.

[0032] Embodiment 1

[0033] Please refer to Figure 1 , Figure 1 It is a schematic diagram of a hybrid BUCK - BOOST topology provided by an embodiment of the present invention. The hybrid BUCK - BOOST topology includes an input voltage source, a first switching transistor S1, a second switching transistor S2, a third switching transistor S3, a fourth switching transistor S4, a fifth switching transistor S5, a sixth switching transistor S6, a first flying capacitor C F1 , a second flying capacitor C F2 , an output capacitor C OUT and a power inductor L. Among them, the negative pole of the input voltage source is connected to the ground terminal, the positive pole of the input voltage source is connected to the first end of the first switching transistor S1 and the first end of the fourth switching transistor S4, and the input voltage source is used to provide an input voltage V IN ; the second end of the first switching transistor S1 is connected to the upper plate of the first flying capacitor C F1 and the first end of the second switching transistor S2, and the second end of the fourth switching transistor S4 is connected to the first flying capacitor C F1The lower plate of, the first end of the sixth switch tube S6, and the first end of the third switch tube S3. The second end of the sixth switch tube S6 is connected to the first end of the fifth switch tube S5 and the second flying capacitor C F2 The lower plate of, the second end of the fifth switch tube S5 is connected to the ground terminal; the second end of the second switch tube S2 is connected to the second end of the third switch tube S3, the upper plate of the second flying capacitor C F2 The upper plate of and the first end of the power inductor L. The second end of the power inductor L is connected to the load I LOAD The first end of and the output capacitor C OUT The upper plate of, the lower plate of the output capacitor C OUT Is connected to the load I LOAD The second end of, and the load I LOAD The second end of is connected to the ground terminal. Preferably, the first flying capacitor C F1 And the second flying capacitor C F2 Have equal capacitance values.

[0034] Embodiment 2

[0035] Based on Embodiment 1, this embodiment provides a control method for a hybrid BUCK - BOOST topology structure to control the six switch tubes in the hybrid BUCK - BOOST topology structure in Embodiment 1 to achieve boost or buck operations.

[0036] The control method of this embodiment adopts a single - mode control strategy. Within one switching period T, the conduction states of the six switch tubes (the first switch tube S1, the second switch tube S2, the third switch tube S3, the fourth switch tube S4, the fifth switch tube S5, and the sixth switch tube S6) of the hybrid BUCK - BOOST topology structure include a first stage And a second stage Two stages. Among them, the time length of the first stage Is equal to the switching period T multiplied by the duty cycle D. Within the first stage , as Figure 2a Shown, the first switch tube, the third switch tube, and the fifth switch tube are turned off, and the second switch tube, the fourth switch tube, and the sixth switch tube are turned on; the time length of the second stage Is equal to the switching period T multiplied by (1 - D). Within the second stage , as Figure 2b Shown, the first switch tube, the third switch tube, and the fifth switch tube are turned on, and the second switch tube, the fourth switch tube, and the sixth switch tube are turned off.

[0037] During the alternating switching of the first stage And the second stage , the first flying capacitor C F1 And the second flying capacitor C F2The voltage at both ends is automatically balanced at V IN / 2.

[0038] The application scenario suitable for the hybrid BUCK - BOOST topology provided in this embodiment is V IN / 2 < V OUT < 3V IN / 2. The hybrid BUCK - BOOST topology of this embodiment is in and The main waveforms of the circuit in the two stages are as Figure 3 shown.

[0039] More specifically, as shown in combination with Figure 2a and Figure 3 In the first stage The voltage values of the switching nodes VA and VC are 3V IN / 2, the voltage values of the switching nodes VB and VD are V IN , the voltage value of the first end of the power inductor L is 3V IN / 2, the voltage value of the second end of the power inductor L is V OUT , the voltage difference across the power inductor is 3V IN / 2 - V OUT > 0, the power inductor L is magnetized, and the current in the power inductor L rises.

[0040] Combined with Figure 2b and Figure 3 shown, in the second stage The voltage value of the switching node VA is V IN , the voltage values of the switching nodes VB and VC are V IN / 2, the voltage value of the switching node VD is 0, the voltage value of the first end of the power inductor L is V IN / 2, the voltage value of the second end of the power inductor L is V OUT , the voltage difference across the power inductor is V IN / 2 - V OUT < 0, the power inductor L demagnetizes.

[0041] Among them, the switching node VA is located on the upper plate of the first flying capacitor C F1 , the switching node VB is located on the lower plate of the first flying capacitor C F1 , the switching node VC is located on the upper plate of the second flying capacitor C F2 , the switching node VD is located on the lower plate of the second flying capacitor C F2 .

[0042] In and In the two stages, the transfer current from input to output in the hybrid BUCK - BOOST topology of this embodiment is continuous.

[0043] For the power inductor L, performing volt-second balance gives:

[0044] D(3V IN / 2 - V OUT ) = (1 - D)(V OUT - V IN / 2)

[0045]

[0046] Among them, M is the voltage conversion ratio, D is the duty cycle, D ∈ (0, 1), M ∈ (0.5, 1.5), the output voltage V OUT is the voltage value at the first end of the load, and the input voltage V IN is the voltage value at the positive terminal of the input voltage source.

[0047] From the above two equations, it can be seen that the relationship between the output voltage V OUT and the input voltage V IN and the duty cycle D is V OUT / V IN = 0.5 + D. After the switching frequency is fixed, adjusting the duty cycle D can effectively control the output voltage V OUT .

[0048] This hybrid BUCK - BOOST topology adopts PWM control. If the duty cycle D is less than 0.5, the output voltage V OUT is less than the input voltage V IN , and the hybrid BUCK - BOOST topology performs a buck operation; if the duty cycle is equal to 0.5, the output voltage V OUT is equal to the input voltage V IN ; if the duty cycle D is greater than 0.5, the output voltage V OUT is greater than the input voltage V IN , and the hybrid BUCK - BOOST topology performs a boost operation.

[0049] In the buck mode and boost mode of this embodiment, the current of the power inductor L is equal to the load current (I L = I LOAD ), which is much lower than the inductor current I L = (M + 1)·I LOAD in the traditional single - control - mode CBBC structure. The first switch tube S1, the second switch tube S2, the third switch tube S3, the fourth switch tube S4, and the sixth switch tube S6 are selected as switch tubes with a maximum breakdown voltage of V IN / 2, and the fifth switch tube S5 is selected as a switch tube with a maximum breakdown voltage of V IN .

[0050] The control method of the hybrid BUCK - BOOST topology provided by the present invention can not only achieve seamless switching between boost and buck operations through a simple control loop, but also effectively reduce the inductor current. On the premise of ensuring high efficiency, it greatly reduces the chip area and inductor size, better meeting the miniaturization requirements of mobile devices. In addition, when the hybrid BUCK - BOOST topology works, it also has the characteristic of continuous output transfer current, which can significantly improve the circuit efficiency and transient response speed.

[0051] Embodiment III

[0052] Based on the above - mentioned embodiments, the embodiment of the present invention further provides a control device for the hybrid BUCK - BOOST topology, which is used to generate the control signals of the six switching tubes required for the hybrid BUCK - BOOST topology.

[0053] Please refer to Figure 4 , Figure 4 which is a schematic diagram of a control device for the hybrid BUCK - BOOST topology provided by the embodiment of the present invention. The control device includes an error amplifier with type - III compensation, a ramp generator, a comparator, a dead - time generation circuit, a level - shifting circuit, and a Buffer. Among them, the non - inverting input terminal and the inverting input terminal of the error amplifier with type - III compensation respectively input a reference voltage Vref and a voltage V OUT sampled and fed back from the output voltage V FB . Among them, the reference voltage Vref is a preset constant, and the output voltage V OUT is the voltage value at the second end of the power inductor L; the output terminal of the error amplifier with type - III compensation is connected to the non - inverting input terminal of the comparator; the output terminal of the ramp generator is connected to the inverting input terminal of the comparator; the output terminal of the comparator is connected to the input terminal of the dead - time generation circuit, and the output terminal of the dead - time generation circuit is connected to the level - shifting circuit. The output terminal of the level - shifting circuit is respectively connected to the control terminals of the first switching tube S1, the second switching tube S2, the third switching tube S3, the fourth switching tube S4, the fifth switching tube S5, and the sixth switching tube S6 in the hybrid BUCK - BOOST topology through corresponding Buffers.

[0054] Further, the level - shifting circuit of this embodiment is used to receive a first control signal and a second control signal from the dead - time generation circuit; the output terminals are respectively connected to the second switching tube S2, the fourth switching tube S4, the sixth switching tube S6, the first switching tube S1, the third switching tube S3, and the fifth switching tube S5 through a buffer.

[0055] Preferably, the phase of the first control signal is the same as that of the input signal of the dead - time generation circuit, and the phase of the second control signal is opposite to that of the input signal of the dead - time generation circuit.

[0056] Specifically, a ramp generator is used to generate a ramp signal, and an error amplifier with type-III compensation is used to amplify the difference between the reference voltage Vref and the voltage V FB , and the output voltage V EA . A comparator is used to compare the ramp signal V RAMP generated by the ramp generator with the voltage V EA output by the error amplifier with type-III compensation, and output a PWM wave according to the comparison result.

[0057] A dead-time generation circuit is used to generate two control signals with dead time based on the PWM wave: a first control signal and a second control signal. And, the phase of the first control signal is the same as the phase of the input signal PWM of the dead-time generation circuit, and the phase of the second control signal is opposite to the phase of the input signal PWM of the dead-time generation circuit.

[0058] When the output voltage V OUT decreases, V FB decreases, and the output voltage V EA of the error amplifier with type-III compensation increases. Since the ramp signal V RAMP output by the ramp generator is fixed, the duty cycle D of the PWM wave output by the comparator increases at this time, and the circuit is in the first stage for a longer time, the magnetization time of the power inductor L increases, and more energy is extracted from the input voltage source, making the output voltage increase.

[0059] When the output voltage increases, V FB increases, and the output voltage V EA of the error amplifier with type-III compensation decreases. At this time, the duty cycle D of the PWM wave output by the comparator decreases, and the circuit is in the first stage for a shorter time, the magnetization time of the power inductor (L) decreases, and less energy is extracted from the input voltage source, making the output voltage decrease.

[0060] Through the above negative feedback regulation, V FB is finally stabilized near the reference voltage Vref, so that the output voltage V OUT is also stabilized at the target value.

[0061] It should be noted that the control method of the hybrid BUCK-BOOST topology of the present invention can also be implemented by using other control devices, which is not limited here.

[0062] The control method and control device of the hybrid BUCK-BOOST topology provided by the present invention can continuously cover buck and boost operations through a single-mode control strategy, realize seamless switching between boost and buck operations, and the control loop is simple; when performing buck and boost operations, the power inductor current (IL ) are all equal to the load current (I LOAD ), reducing the current on the power inductor (L), thus ensuring high efficiency; on the premise of ensuring high efficiency, a small-sized inductor with a large DCR (parasitic DC resistance) can be selected; the maximum breakdown voltage value of the switching transistors in the system is V IN , and there is no need to use high-voltage devices, which can make the chip have a smaller area and lower manufacturing cost; when adopting a stacked transistor structure, all the switching transistors of the system can be implemented by switching transistors with a maximum breakdown voltage value of V IN / 2. The on-resistance of the switching transistors is reduced, and the conduction loss is lowered; it has a continuous input-output transfer current (OTC) and a fast transient response speed.

[0063] In several embodiments provided by the present invention, it should be understood that the devices and methods disclosed by the present invention can be implemented in other ways. For example, the device embodiments described above are only illustrative. For example, the division of the modules is only a logical function division. In actual implementation, there may be other division methods. For example, multiple modules or components can be combined or integrated into another system, or some features can be ignored or not executed.

[0064] In addition, in each embodiment of the present invention, the functional modules can be integrated in a processing module, or each module can exist physically alone, or two or more modules can be integrated in one module. The above integrated modules can be implemented in the form of hardware, or in the form of a combination of hardware and software functional modules.

[0065] The above content is a further detailed description of the present invention in combination with specific preferred implementation manners, and it cannot be determined that the specific implementation of the present invention is only limited to these descriptions. For those of ordinary skill in the technical field to which the present invention belongs, without departing from the concept of the present invention, several simple deductions or substitutions can still be made, and all should be regarded as belonging to the protection scope of the present invention.

Claims

1. A hybrid BUCK-BOOST topology, characterized in that: The system includes an input voltage source, a first switch tube S1, a second switch tube S2, a third switch tube S3, a fourth switch tube S4, a fifth switch tube S5, a sixth switch tube S6, a first flying capacitor C F1 , the second flying capacitor C F2 , output capacitor C OUT and power inductor L, where The negative electrode of the input voltage source is connected to the ground terminal, the positive electrode of the input voltage source is connected to the first end of the first switch tube S1 and the first end of the fourth switch tube S4, and the input voltage source is used to provide an input voltage V IN ; The second end of the first switch tube S1 is connected to the first flying capacitor C F1 The second end of the fourth switch tube S4 is connected to the first flying capacitor C F1 The second end of the sixth switch tube S6 is connected to the first end of the fifth switch tube S5 and the second flying capacitor C F2 The second end of the fifth switch tube S5 is connected to the ground end; The second end of the second switch tube S2 is connected to the second end of the third switch tube S3 and the second flying capacitor C F2 The upper plate and the first end of the power inductor L, the second end of the power inductor L is connected to the load I LOAD The first end and the output capacitor C OUT The upper plate of the output capacitor C OUT The lower plate is connected to the load I LOAD The second end of the load I LOAD The second end is connected to the ground end.

2. The hybrid BUCK-BOOST topology according to claim 1, characterized in that: The first flying capacitor C F1 and the second flying capacitor C F2 The capacitance values ​​are equal.

3. The hybrid BUCK-BOOST topology according to claim 1, characterized in that: Input voltage V IN , output voltage V OUT The relationship between V OUT / V IN =0.5+D, where the output voltage V OUT is the voltage value of the second end of the power inductor L.

4. The hybrid BUCK-BOOST topology according to claim 1, characterized in that: The maximum withstand voltage of the first switch tube S1, the second switch tube S2, the third switch tube S3, the fourth switch tube S4 and the sixth switch tube S6 is selected to be V IN / 2 switch tube, the fifth switch tube S5 is selected to have a maximum withstand voltage of V IN The switch tube.

5. The hybrid BUCK-BOOST topology according to claim 1, characterized in that: In the buck mode and the boost mode, the current of the power inductor L is equal to the current of the load.

6. A control method for a hybrid BUCK-BOOST topology, characterized in that: Used to control the hybrid BUCK-BOOST topology structure of claim 1 or 5, the control method adopts a single-mode control strategy, and within a switching cycle T, the conduction states of the first switch tube S1, the second switch tube S2, the third switch tube S3, the fourth switch tube S4, the fifth switch tube S5, and the sixth switch tube S6 of the hybrid BUCK-BOOST topology structure include a first stage of alternating switching and the second stage in, In the first stage In the embodiment, the first switch tube S1, the third switch tube S3 and the fifth switch tube S5 are controlled to be turned off, and the second switch tube S2, the fourth switch tube S4 and the sixth switch tube S6 are controlled to be turned on; In the second stage The first switch tube, the third switch tube and the fifth switch tube are controlled to be turned on, and the second switch tube, the fourth switch tube and the sixth switch tube are controlled to be turned off.

7. The control method of the hybrid BUCK-BOOST topology structure according to claim 6, characterized in that: The first stage The duration of the second phase is equal to the switching period T multiplied by the duty cycle D; The length of time is equal to the switching period T multiplied by (1-D).

8. A control device of a hybrid BUCK-BOOST topology, characterized in that: Used to control the hybrid BUCK-BOOST topology structure described in claim 1 or 5, the control device includes an error amplifier with type III compensation, a ramp generator, a comparator, a dead time generation circuit, a level shift circuit and a buffer, wherein: The non-inverting input terminal and the inverting input terminal of the error amplifier with type III compensation are respectively input with a reference voltage Vref and an output voltage V OUT The voltage V sampled at the feedback FB , wherein the reference voltage Vref is a preset constant, and the output voltage V OUT is the voltage value of the second end of the power inductor L; the output end of the error amplifier with type III compensation is connected to the non-inverting input end of the comparator; the output end of the ramp generator is connected to the inverting input end of the comparator; The output end of the comparator is connected to the input end of the dead time generating circuit, the output end of the dead time generating circuit is connected to the level shifting circuit, and the output end of the level shifting circuit is connected to the control ends of the first switch tube S1, the second switch tube S2, the third switch tube S3, the fourth switch tube S4, the fifth switch tube S5 and the sixth switch tube S6 in the hybrid BUCK-BOOST topology structure through corresponding buffers.

9. The control device of the hybrid BUCK-BOOST topology structure according to claim 8, characterized in that: The first control signal has the same phase as an input signal of the dead time generating circuit, and the second control signal has an opposite phase to the input signal of the dead time generating circuit.

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