DC conversion circuit and DC conversion device

Abstract

The invention discloses a direct current conversion circuit and a direct current conversion device, and belongs to the technical field of power converters. The DC conversion circuit comprises an input port, a first voltage conversion unit, a second voltage conversion unit and an output port. The first voltage conversion unit is used for converting the first voltage into an output voltage; the first voltage conversion unit comprises a first switching module which responds to a first control signal and controls one of at least two harmonic sub-circuits included in the resonance module to be switched on; and the input capacitor module is used for outputting the stored second voltage to the second voltage conversion unit. The second voltage conversion unit is used for converting the second voltage into an output voltage; and the second switching module comprises a second switching module which can respond to a second control signal and control a corresponding switch to be switched on so as to cooperatively work with the voltage reduction module to convert the second voltage into the output voltage. According to the invention, the current load capacity can be increased while high-power-density voltage reduction is realized.

Description

Technical Field

[0001] The present application relates to the technical field of power converters, and in particular to a DC conversion circuit and a DC conversion device. Background Art

[0002] In recent years, with the popularity of artificial intelligence, cloud computing and IoT devices and the growing demand for high-performance computing, the power consumption of data centers has risen rapidly. Therefore, the quality of power supply has an important impact on the operating cost, maintenance cost and data security of data centers. The intermediate bus converter in the three-level power supply architecture of the data center often needs to assume the function of converting the 48V bus voltage to low voltage and supplying energy to the subsequent load point converter. In the related art, the traditional three-level power supply architecture often uses 12V as the output voltage of the intermediate bus converter to adapt to the input of the load point converter under the existing 12V standard. Switched capacitor, switched resonant and inductor-inductor-capacitor (LLC) resonant converters are often used in bus converter design. However, the 12V intermediate voltage puts forward higher voltage resistance requirements on the switches and passive components of the subsequent load point converter, reduces the quality factor of the components used and limits the efficiency and power density of the overall architecture. In order to improve the performance of the overall architecture, more work has been explored in recent years to reduce the intermediate voltage to around 5V. However, the lower intermediate voltage requires the intermediate bus converter to provide a higher voltage conversion ratio, increases the number of stages of the switched capacitor converter and the switched resonant converter, and increases the turns ratio of the LLC transformer, limiting its performance. As a result, the traditional intermediate bus converter structure is not sufficient to meet higher performance requirements, and the actual voltage value of a typical 48V voltage bus may fluctuate between 48V and 60V. The traditional intermediate bus converter cannot adapt to a wide range of inputs and provide stable low-voltage outputs. Summary of the invention

[0003] The present application provides a DC conversion circuit and a DC conversion device, which can increase the current load capacity while achieving high power density voltage reduction. The technical solution is as follows:

[0004] In one aspect, a DC conversion circuit is provided, comprising an input port, a first voltage conversion unit, a second voltage conversion unit, and an output port;

[0005] The input port is used to receive an input voltage;

[0006] The first voltage conversion unit is used to convert a first voltage in the input voltage into an output voltage and output it through the output port; the first voltage conversion unit includes a first switching module, a resonance module, an input capacitor module and a power transmission module, the first switching module controls one of at least two resonant sub-circuits included in the resonance module to be turned on in response to a first control signal; the input capacitor module is used to output a stored second voltage to the second voltage conversion unit, the second voltage being a voltage in the input voltage other than the first voltage; the power transmission module is used to obtain current through inductive coupling, and provide the required output current to the load through the output port;

[0007] The second voltage conversion unit is used to convert the second voltage into the output voltage and output it through the output port; the second voltage conversion unit includes a second switching module and a step-down module. The second switching module responds to a second control signal and controls the corresponding switch in the second switching module to close according to a second duty cycle, so as to work in conjunction with the step-down module to convert the second voltage into the output voltage.

[0008] Optionally, the first switching module includes a first switch group, a second switch group, a third switch group and a fourth switch group;

[0009] The resonance module includes a first resonant subcircuit, a second resonant subcircuit, a third resonant subcircuit and a fourth resonant subcircuit;

[0010] The input capacitor module includes a capacitor C S1 , capacitor C S2 , capacitor C S3 and capacitor C S4 ;

[0011] The first switching module is specifically used for:

[0012] In response to the first control signal, the first switch group, the second switch group, the third switch group and the fourth switch group are closed in sequence according to the first duty cycle corresponding to the first control signal, so as to turn on the first resonant sub-circuit, the second resonant sub-circuit, the third resonant sub-circuit and the fourth resonant sub-circuit in sequence, and the capacitor C S2 , the capacitor C S3 , the capacitor C S4 and the capacitor C S1 to charge.

[0013] Optionally, when the first switch group is closed, the capacitor C S1 outputting the second voltage to the second voltage conversion unit;

[0014] The first switch group includes a switch S1, a switch S6 and a switch S R1 The first resonant subcircuit includes a flying capacitor C F1 、Flying capacitor C F2 and inductor L C2 , the flying capacitor C F1 One end of the flying capacitor C is connected to the switch S1. F1 The other end of the capacitor C S2 One end of the inductor L C2 One end of the flying capacitor C F2 One end of the flying capacitor C is connected to the switch S6. F2 The other end is connected to the power transmission module;

[0015] The capacitor C S2 The other end of the capacitor C is connected to the switch S6. S2 The capacitance value is greater than the flying capacitor C F1 And the flying capacitor C F2 The capacitance value is such that the capacitor C S2 is charged, so that the capacitor C S2 The voltage is equal to the second voltage.

[0016] Optionally, when the second switch group is closed, the capacitor C S2 outputting the second voltage to the second voltage conversion unit;

[0017] The second switch group includes a switch S2, a switch S7 and a switch S R2 The second resonant subcircuit includes a flying capacitor C F2 、Flying capacitor C F3 and inductor L C3 , the flying capacitor C F2 One end of the flying capacitor C is connected to the switch S2. F2 The other end of the capacitor C S3 One end of the inductor L C3 One end of the flying capacitor C F3 One end of the flying capacitor C is connected to the switch S7. F3 The other end is connected to the power transmission module;

[0018] The capacitor C S3 The other end of the capacitor C is connected to the switch S7. S3 The capacitance value is greater than the flying capacitor C F2 And the flying capacitor C F3 The capacitance value is such that the capacitor C S3 is charged, so that the capacitor C S3The voltage is equal to the second voltage.

[0019] Optionally, when the third switch group is closed, the capacitor C S3 outputting the second voltage to the second voltage conversion unit;

[0020] The third switch group includes switches S3, S8 and S R3 The third resonant subcircuit includes a flying capacitor C F3 、Flying capacitor C F4 and inductor L C4 , the flying capacitor C F3 One end of the flying capacitor C is connected to the switch S3. F3 The other end of the capacitor C S4 One end of the inductor L C4 One end of the flying capacitor C F4 One end of the flying capacitor C is connected to the switch S8. F4 The other end is connected to the power transmission module;

[0021] The capacitor C S4 The other end of the capacitor C is connected to the switch S8. S4 The capacitance value is greater than the flying capacitor C F3 And the flying capacitor C F4 The capacitance value is such that the capacitor C S4 is charged, so that the capacitor C S4 The voltage is equal to the second voltage.

[0022] Optionally, when the fourth switch group is closed, the capacitor C S4 outputting the second voltage to the second voltage conversion unit;

[0023] The fourth switch group includes switches S4, S5 and S R4 The fourth resonant subcircuit includes a flying capacitor C F4 、Flying capacitor C F1 and inductor L C1 , the flying capacitor C F4 One end of the flying capacitor C is connected to the switch S4. F1 The other end of the capacitor C S1 One end of the inductor L C1 One end of the flying capacitor C F1 One end of the flying capacitor C is connected to the switch S5. F1 The other end is connected to the power transmission module;

[0024] The capacitor C S1The other end of the capacitor C is connected to the switch S5. S1 The capacitance value is greater than the flying capacitor C F4 And the flying capacitor C F1 The capacitance value is such that the capacitor C S1 is charged, so that the capacitor C S1 The voltage is equal to the second voltage.

[0025] Optionally, the power transmission module includes the inductor L C1 , the inductor L C2 , the inductor L C3 and the inductance L C4 , and the inductance L C1 , the inductor L C2 , the inductor L C3 and the inductance L C4 coupling.

[0026] Optionally, the second switching module includes a switch S H1 , switch S H2 , switch S H3 , switch S H4 and switch S L ; The switch S H1 One end of the capacitor C S1 connection, the switch S H1 The other end is used to connect to the switch S L and connected to the step-down module; the switch S H2 One end of the capacitor C S2 connection, the switch S H2 The other end is used to connect to the switch S L and connected to the step-down module; the switch S H3 One end of the capacitor C S3 connection, the switch S H2 The other end is used to connect to the switch S L and connected to the step-down module; the switch S H3 One end of the capacitor C S3 connection, the switch S H3 The other end is used to connect to the switch S L Connected to the step-down module;

[0027] The second switching module controls the corresponding switch in the second switching module to close according to the second duty cycle in response to the second control signal, including:

[0028] When the first switch group is closed, the second switching module controls the switch S according to the second duty cycle in response to the second control signal. H1 and switch S L closure;

[0029] When the second switch group is closed, the second switching module controls the switch S according to the second duty cycle in response to the second control signal. H2 and switch S L closure;

[0030] When the third switch group is closed, the second switching module controls the switch S according to the second duty cycle in response to the second control signal. H3 and switch S L closure;

[0031] When the fourth switch group is closed, the second switching module controls the switch S according to the second duty cycle in response to the second control signal. H4 and switch S L closure;

[0032] The second duty cycle is determined according to the output voltage and the second voltage.

[0033] In another aspect, a DC conversion device is provided, comprising:

[0034] A DC conversion circuit, wherein the DC conversion circuit adopts the DC conversion circuit described in any one of the above embodiments;

[0035] The control module is used to output a first control signal and a second control signal to control the DC conversion circuit to work.

[0036] Optionally, the control module further includes:

[0037] A plurality of high-side switch driving subcircuits, used for driving switches S1 to S8 to close or open them; each of the plurality of high-side switch driving subcircuits comprises a first energy storage submodule, a first switch submodule, a second switch submodule, a third switch submodule, a logic control submodule and a driving submodule;

[0038] One end of the first energy storage submodule is respectively connected to the input port and the first pole of the third switch submodule, and the other end of the first energy storage submodule is used to be respectively connected to the first pole of the first switch submodule and the first pole of the second switch submodule; the second pole of the first switch submodule is used to be grounded, and the third pole of the first switch submodule is used to receive a third control signal; the second pole of the second switch submodule is connected to the power supply, and the third pole of the second switch submodule is used to receive a third control signal; the second pole of the third switch submodule is respectively connected to the control end of the target switch and one end of the driving submodule, and the third pole of the third switch submodule is used to receive a fourth control signal, and the target switch is the switch that currently needs to be closed among the switches S1 to S8; the receiving end of the target switch is connected to the other end of the driving submodule, and the transmitting end of the target switch is used to connect to other parts in the DC conversion circuit; the logic control submodule is used to send the third control signal and the fourth control signal;

[0039] Among them, when the first switch submodule is turned on and the second switch submodule is turned off, the first energy storage submodule can be charged through the input port, and the voltage of the first energy storage submodule is equal to the input voltage corresponding to the input port; when the second switch submodule is turned on and the first switch submodule is turned off, the first energy storage submodule can be charged through the input port and the power supply, and the voltage of the first energy storage submodule is equal to the sum of the input voltage and the voltage of the power supply; the third switch submodule is used to select whether to charge the energy storage capacitor in the driving submodule.

[0040] The technical solution provided by this application can at least bring the following beneficial effects:

[0041] The first voltage conversion unit in the DC conversion circuit of the embodiment of the present application includes a first switching module, a resonance module, and an input capacitor module, and the resonance module includes at least two resonant sub-circuits. The first switching module can turn on the resonant sub-circuit in response to the first control signal and charge the input capacitor module. In this way, not only can high power density voltage reduction be achieved, but also resonant soft switching and capacitor soft charging can be achieved. Moreover, the current load capacity of the DC conversion circuit can be increased by introducing a multi-phase current path. In addition, the input capacitor module can output the second voltage stored in itself to the second voltage conversion unit. The second voltage conversion unit works in a pulse width modulation mode, that is, the second duty cycle corresponding to the second control signal can be modulated, and the second voltage is the voltage in the output voltage other than the first voltage. Therefore, the embodiment of the present application can achieve bus regulation by changing the input capacitor module to adapt to possible bus voltage fluctuations. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 A schematic diagram of the structure of a DC conversion circuit provided in an embodiment of the present application;

[0043] Figure 2 A schematic diagram of the structure of another DC conversion circuit provided in an embodiment of the present application;

[0044] Figure 3 A schematic diagram of a first duty cycle provided in an embodiment of the present application;

[0045] Figure 4 A schematic diagram of a structure of a path corresponding to a DC conversion circuit when a first switch group is closed provided in an embodiment of the present application;

[0046] Figure 5 A schematic diagram of a structure of a path corresponding to a DC conversion circuit when a second switch group is closed provided in an embodiment of the present application;

[0047] Figure 6 A schematic structural diagram of a path corresponding to a DC conversion circuit when a third switch group is closed provided in an embodiment of the present application;

[0048] Figure 7 A schematic structural diagram of a path corresponding to a DC conversion circuit when a fourth switch group is closed provided in an embodiment of the present application;

[0049] Figure 8 A schematic diagram of the structure of another DC conversion circuit provided in an embodiment of the present application;

[0050] Fig. 9 A schematic diagram of the structure of a DC conversion device provided in an embodiment of the present application;

[0051] Fig.10 A schematic diagram of the structure of a high-side switch driving subcircuit provided in an embodiment of the present application. DETAILED DESCRIPTION

[0052] The present invention is further described in detail below by specific embodiments in conjunction with the accompanying drawings. Wherein similar elements in different embodiments adopt associated similar element numbers. In the following embodiments, many detailed descriptions are for making the present application better understood. However, those skilled in the art can easily recognize that some features can be omitted in different situations, or can be replaced by other elements, materials, methods. In some cases, some operations related to the present application are not shown or described in the specification, this is to avoid the core part of the present application being overwhelmed by too much description, and for those skilled in the art, it is not necessary to describe these related operations in detail, and they can fully understand the related operations according to the description in the specification and the general technical knowledge in the art.

[0053] In addition, the features, operations or characteristics described in the specification can be combined in any appropriate manner to form various implementations. At the same time, the steps or actions in the method description can also be interchanged or adjusted in a manner that is obvious to those skilled in the art. Therefore, the various sequences in the specification and the drawings are only for the purpose of clearly describing a certain embodiment and are not meant to be a required sequence, unless otherwise specified that a certain sequence must be followed.

[0054] The serial numbers of the components in this document, such as "first", "second", etc., are only used to distinguish the objects described and do not have any order or technical meaning. The "connection" and "coupling" mentioned in this application, unless otherwise specified, include direct and indirect connections (couplings).

[0055] In the related art, the traditional LLC converter realizes voltage conversion through the transformer turns ratio, uses the transformer leakage inductance to participate in resonance, and the self-inductance current helps the converter to achieve complete soft switching and soft charging, with high conversion efficiency. However, due to the high voltage conversion ratio, the transformer turns ratio is increased, which limits the power density of the converter. For the traditional switched capacitor / resonant converter, the increase in voltage conversion ratio increases the number of converter stages, and also increases the volume and loss of the converter. Therefore, the traditional structure cannot take into account both the converter power density and conversion efficiency. In addition, the traditional resonant converter has no bus regulation capability in the resonant mode, that is, the traditional resonant converter operates at a fixed duty cycle, and due to the fixed voltage conversion ratio, bus and load regulation cannot be achieved.

[0056] Based on this, the present application provides a DC conversion circuit and a DC conversion device, which can achieve high power density voltage reduction, and realize resonant soft switching and capacitor soft charging. In addition, the present application embodiment can increase the current load capacity of the DC conversion circuit by introducing a multi-phase current path. Moreover, the DC conversion circuit in the embodiment of the present application introduces an input capacitor module in the first voltage conversion unit, and a second voltage conversion unit operating in a pulse width modulation mode, and realizes bus regulation by changing the voltage in the input capacitor module to adapt to possible bus voltage fluctuations. The following is a detailed explanation.

[0057] Please refer to Figure 1 , Figure 1It is a structural schematic diagram of a DC conversion circuit 1 provided in an embodiment of the present application. The DC conversion circuit 1 includes an input port 11, a first voltage conversion unit 12, a second voltage conversion unit 13 and an output port 14. The input port 11 is used to receive an input voltage. The first voltage conversion unit 12 is used to convert a first voltage in the input voltage into an output voltage and output it through the output port 14; the first voltage conversion unit 12 includes a first switching module 121, a resonance module 122, an input capacitor module 123 and a power transmission module 124, and the first switching module 121 controls the conduction of at least one of the two resonant sub-circuits included in the resonance module 122 in response to a first control signal; the input capacitor module 123 is used to output the stored second voltage to the second voltage conversion unit 13, and the second voltage is a voltage in the input voltage other than the first voltage; the power transmission module 124 is used to obtain current through inductive coupling, and provide the required output current to the load through the output port 14. The second voltage conversion unit 13 is used to convert the second voltage into an output voltage and output it through the output port 14; the second voltage conversion unit 13 includes a second switching module 131 and a step-down module 132. The second switching module 131 responds to the second control signal and controls the corresponding switch in the second switching module 131 to close according to the second duty cycle, so as to work together with the step-down module 132 to convert the second voltage into an output voltage.

[0058] That is, the first voltage conversion unit 12 converts the first voltage in the input voltage into the desired output voltage, and the second voltage conversion unit 13 converts the second voltage in the input voltage other than the first voltage into the desired output voltage, that is, the first voltage conversion unit 12 and the second voltage conversion unit 13 work together to convert the input voltage into the desired output voltage, that is, the DC conversion circuit 1 is equivalent to a series input parallel output circuit. For example, assuming that a voltage conversion of 48V to 5V is currently required, the first voltage conversion unit 12 can perform a 40V to 5V conversion operation, and the obtained 5V voltage is output from the output port 14, and the second voltage conversion unit 13 performs the remaining 8V to 5V conversion operation, and the obtained 5V voltage is output from the output port 14. Therefore, even if the voltage conversion ratio of the first voltage conversion unit 12 is fixed and the actual voltage value of the voltage bus changes, resulting in a change in the input voltage, the second voltage conversion unit 13 can perform voltage conversion so that the DC conversion circuit 1 can adapt to a wide range of inputs and provide a stable low-voltage output.

[0059] The first voltage conversion unit 12 includes a first switching module 121, a resonance module 122, an input capacitor module 123 and a power transmission module 124. The first switching module 121 controls one of at least two resonant sub-circuits included in the resonance module 122 to be turned on in response to a first control signal. That is, the resonance module 122 includes at least two resonant sub-circuits, and the current load capacity of the DC converter can be increased by introducing a multi-phase current path. The first switching module 121 can control one of the resonant sub-circuits to be turned on in response to the first control signal, thereby enabling the input capacitor module 123 to be charged, and can achieve resonant soft switching and capacitor soft charging.

[0060] Continuing with the above description, after the resonant subcircuit is turned on, the input capacitor module 123 can be charged, thereby enabling the voltage in the input capacitor module 123 to be equal to the second voltage, and then outputting the second voltage to the second voltage conversion unit 13, so that the second voltage conversion unit 13 can convert the second voltage into the desired output voltage. In other words, the voltage in the input capacitor module 123 can change with the magnitude of the input voltage. For example, assuming that the first voltage conversion unit 12 can convert 40V to 5V, if the input voltage is 48V, then the corresponding voltage in the input capacitor module 123 is 8V; if the input voltage is 50V, then the corresponding voltage in the input capacitor module 123 is 10V. In this way, bus regulation is achieved by changing the voltage in the input capacitor module 123 to adapt to possible bus voltage fluctuations.

[0061] The first voltage conversion unit 12 also includes a power transmission module 124. When the resonant subcircuit is turned on, the power transmission module 124 can obtain current through inductive coupling, and synthesize the obtained current into an output current that meets the load demand, thereby performing stable current output.

[0062] Based on the above description, it can be known that the second voltage conversion unit 13 is used to convert the second voltage into an output voltage, and the resonance module 122 includes at least two resonant sub-circuits. The second voltage conversion unit 13 also includes a second switching module 131, and the second switching module 131 includes a plurality of switches, so that when the corresponding resonant sub-circuit is turned on, the second switching module 131 can respond to the second control signal and control the corresponding switch to close according to the second duty cycle, so as to work in coordination with the step-down module 132 to convert the second voltage into an output voltage.

[0063] In some embodiments, please refer to Figure 2 ,from Figure 2It can be seen that the first switching module 121 includes a first switch group 1211, a second switch group 1212, a third switch group 1213 and a fourth switch group 1214. The resonance module 122 includes a first resonant subcircuit 1221, a second resonant subcircuit 1222, a third resonant subcircuit 1223 and a fourth resonant subcircuit 1224. The input capacitor module 123 includes a capacitor C S1 , capacitor C S2 , capacitor C S3 and capacitor C S4 The first switching module 121 can respond to the first control signal and sequentially close the first switch group 1211, the second switch group 1212, the third switch group 1213 and the fourth switch group 1214 according to the first duty cycle corresponding to the first control signal, so as to sequentially turn on the first resonant subcircuit 1221, the second resonant subcircuit 1222, the third resonant subcircuit 1223 and the fourth resonant subcircuit 1224, and provide a capacitor C S2 , capacitor C S3 , capacitor C S4 and capacitor C S1 to charge.

[0064] That is, the first switching module 121 can respond to the first control signal and sequentially close the first switch group 1211, the second switch group 1212, the third switch group 1213 and the fourth switch group 1214 according to the first duty cycle. When the first switch group 1211 is closed, the first resonant subcircuit 1221 is turned on, and the capacitor C S2 can be charged so that the capacitor C S2 When the second switch group 1212 is closed, the second voltage is input to the second voltage conversion unit 13; when the second switch group 1212 is closed, the second resonant subcircuit 1222 can be turned on, and the capacitor C S3 can be charged so that the capacitor C S3 When the third switch group 1213 is closed, the second voltage is input to the second voltage conversion unit 13; when the third switch group 1213 is closed, the third resonant subcircuit 1223 is turned on, and the capacitor C S4 can be charged so that the capacitor C S4 When the fourth switch group 1214 is closed, the second voltage is input to the second voltage conversion unit 13; when the fourth switch group 1214 is closed, the fourth resonant subcircuit 1224 can be turned on, and the capacitor C S1 can be charged so that the capacitor C S1 When the first switch group 1211 is closed, the second voltage is input to the second voltage conversion unit 13 .

[0065] It should be noted that the first switching module 121 includes a first switch group 1211, a second switch group 1212, a third switch group 1213 and a fourth switch group 1214, the resonance module 122 includes a first resonant subcircuit 1221, a second resonant subcircuit 1222, a third resonant subcircuit 1223 and a fourth resonant subcircuit 1224, and the input capacitor module 123 includes a capacitor C S1 , capacitor C S2 , capacitor C S3 and capacitor C S4 The resonance module 122 includes a first resonant sub-circuit 1221, a second resonant sub-circuit 1222, a third resonant sub-circuit 1223 and a fourth resonant sub-circuit 1224, that is, there are four-phase current paths for illustration, or, in application, more or fewer phase current paths can be introduced according to actual needs, which is not limited in the embodiments of the present application.

[0066] In some embodiments, the schematic diagram of the first duty cycle can be as follows: Figure 3 As shown, Figure 3 This is a schematic diagram of the first duty cycle in a cycle. Figure 3 It can be seen that, from 0 to t1, the first switch group 1211 is closed, and the second switch group 1212, the third switch group 1213 and the fourth switch group 1214 are opened; from T / 4 to t2, the second switch group 1212 is closed, and the first switch group 1211, the third switch group 1213 and the fourth switch group 1214 are opened; from T / 2 to t3, the third switch group 1213 is closed, and the first switch group 1211, the second switch group 1212 and the fourth switch group 1214 are opened; from 3T / 4 to t4, the fourth switch group 1214 is closed, and the first switch group 1211, the second switch group 1212 and the third switch group 1213 are opened.

[0067] In addition, in some embodiments, after each switch group finishes working, there will be a period of time when all switch groups are in the off state, that is, there is a dead time. The self-inductance current obtained by the power transmission module 124 will also charge or discharge the switch groups used to achieve soft switching of all switch groups. For example, please refer to Figure 3 ,from Figure 3 It can be seen that after the first switch group 1211 finishes working, t1 value T / 4 is the dead time; after the second switch group 1212 finishes working, t2 to T / 2 is the dead time; after the third switch group 1213 finishes working, t3 value 3T / 4 is the dead time; after the fourth switch group 1214 finishes working, t4 to T is the dead time.

[0068] It should be noted that Figure 3The first duty cycle shown is for illustration only. In application, the first duty cycle can also be determined according to actual conditions. That is to say, the embodiment of the present application does not limit the first duty cycle.

[0069] In some embodiments, when the first switch group 1211 is closed, the capacitor C S1 Output the second voltage to the second voltage conversion unit 13; please refer to Figure 4 The first switch group 1211 includes a switch S1, a switch S6 and a switch S R1 The first resonant subcircuit 1221 includes a flying capacitor C F1 、Flying capacitor C F2 and inductor L C2 , flying capacitor C F1 One end of the switch S1 is connected to the flying capacitor C F1 The other end of the capacitor C S2 One end of the inductor L C2 One end of the flying capacitor C F2 One end of the switch S6 is connected to the flying capacitor C F2 The other end of the capacitor C is connected to the power transmission module 124; S2 The other end is connected to switch S6, capacitor C S2 The capacitance value is greater than the flying capacitor C F1 And the flying capacitor C F2 The capacitance value is so that the capacitor C S2 The capacitor C S2 The voltage is equal to the second voltage.

[0070] In some embodiments, when the first switch group 1211 is closed, the inductor L C2 The leakage inductance of L participates in the resonance, that is, not the entire inductance L C2 All of them will participate in the resonance. Among them, leakage inductance refers to the parasitic inductance caused by incomplete coupling of magnetic flux.

[0071] Based on the above description, it can be known that when the fourth switch group 1214 is closed, the capacitor C S1 Thus, the switch S in the first switch group 1211 is R1 When closed, the capacitor C S1 The second voltage can be output to the second voltage conversion unit 13 .

[0072] Continuing with the above description, since the switches S1 and S6 in the first switch group 1211 are closed, the flying capacitor C F1 、Flying capacitor C F2 and inductor L C2 In addition, due to the capacitor C S2 The capacitance value is much larger than the flying capacitor C F1 And the flying capacitor CF2 The capacitance value, therefore, is S2 Does not participate in resonance. And the flying capacitor C F1 One end of the flying capacitor C is connected to the switch S1, and the other end of the switch S1 is connected to the input port 11. F1 To charge the flying capacitor C F2 Discharge. And the flying capacitor C F2 and capacitor C S2 A switch S6 is connected between them. Therefore, when the switch S6 is closed, due to the flying capacitor C F2 discharge, so that the capacitor C S2 In addition, the flying capacitor C F2 It is also connected to the power transmission module 124, so that when the first resonant sub-circuit 1221 is turned on, the power transmission module 124 can receive energy from the first resonant sub-circuit 1221 to obtain current through inductive coupling, and provide the required output current to the load through the output port 14.

[0073] In some embodiments, when the second switch group 1212 is closed, the capacitor C S2 Output the second voltage to the second voltage conversion unit 13; please refer to Figure 5 The second switch group 1212 includes a switch S2, a switch S7 and a switch S R2 The second resonant subcircuit 1222 includes a flying capacitor C F2 、Flying capacitor C F3 and inductor L C3 , flying capacitor C F2 One end of the switch S2 is connected to the flying capacitor C F2 The other end of the capacitor C S3 One end of the inductor L C3 One end of the flying capacitor C F3 One end of the switch S7 is connected to the flying capacitor C F3 The other end of the capacitor C is connected to the power transmission module 124; S3 The other end is connected to switch S7, capacitor C S3 The capacitance value is greater than the flying capacitor C F2 And the flying capacitor C F3 The capacitance value is so that the capacitor C S3 The capacitor C S3 The voltage is equal to the second voltage.

[0074] In some embodiments, when the second switch group 1212 is closed, the inductor L C3 The leakage inductance of L participates in the resonance, that is, not the entire inductance L C3 All will participate in resonance.

[0075] Based on the above description, it can be seen that when the first switch group 1211 is closed, the capacitor C S2 Thus, the switch S in the second switch group 1212 is R2 When closed, the capacitor C S2 The second voltage can be output to the second voltage conversion unit 13 .

[0076] Continuing with the above description, since the switches S2 and S7 in the second switch group 1212 are closed, the flying capacitor C F2 、Flying capacitor C F3 and inductor L C3 In addition, due to the capacitor C S3 The capacitance value is much larger than the flying capacitor C F2 And the flying capacitor C F3 The capacitance value, therefore, is S3 Does not participate in resonance. And the flying capacitor C F2 One end of the flying capacitor C is connected to the switch S2, and the other end of the switch S2 is connected to the input port 11. F2 To charge the flying capacitor C F3 Discharge. And the flying capacitor C F3 and capacitor C S3 A switch S7 is connected between them. Therefore, when the switch S7 is closed, due to the flying capacitor C F3 discharge, so that the capacitor C S3 In addition, the flying capacitor C F3 It is also connected to the power transmission module 124, so that when the second resonant sub-circuit 1222 is turned on, the power transmission module 124 can receive energy from the second resonant sub-circuit 1222 to obtain current through inductive coupling and provide the required output current to the load through the output port 14.

[0077] In some embodiments, when the third switch group 1213 is closed, the capacitor C S3 Output the second voltage to the second voltage conversion unit 13; please refer to Figure 6 The third switch group 1213 includes a switch S3, a switch S8 and a switch S R3 The third resonant subcircuit 1223 includes a flying capacitor C F3 、Flying capacitor C F4 and inductor L C4 , flying capacitor C F3 One end of the switch S3 is connected to the flying capacitor C F3 The other end of the capacitor C S4 One end of the inductor L C4 One end of the flying capacitor C F4 One end of the flying capacitor C is connected to the switch S8. F4The other end of the capacitor C is connected to the power transmission module 124; S4 The other end is connected to switch S8, capacitor C S4 The capacitance value is greater than the flying capacitor C F3 And the flying capacitor C F4 The capacitance value is so that the capacitor C S4 The capacitor C S4 The voltage is equal to the second voltage.

[0078] In some embodiments, when the third switch group 1213 is closed, the inductor L C4 The leakage inductance of L participates in the resonance, that is, not the entire inductance L C4 All will participate in resonance.

[0079] Based on the above description, it can be seen that when the second switch group 1212 is closed, the capacitor C S3 Therefore, the switch S in the third switch group 1213 is R3 When closed, the capacitor C S3 The second voltage can be output to the second voltage conversion unit 13 .

[0080] Continuing with the above description, since the switches S3 and S8 in the third switch group 1213 are closed, the flying capacitor C F3 、Flying capacitor C F4 and inductor L C4 In addition, due to the capacitor C S4 The capacitance value is much larger than the flying capacitor C F3 And the flying capacitor C F4 The capacitance value, therefore, is S4 Does not participate in resonance. And the flying capacitor C F3 One end of the flying capacitor C is connected to the switch S3, and the other end of the switch S3 is connected to the input port 11. F3 To charge the flying capacitor C F4 Discharge. And the flying capacitor C F4 and capacitor C S4 A switch S8 is connected between them. Therefore, when the switch S8 is closed, due to the flying capacitor C F4 discharge, so that the capacitor C S4 In addition, the flying capacitor C F3 It is also connected to the power transmission module 124, so that when the third resonant sub-circuit 1223 is turned on, the power transmission module 124 can receive energy from the third resonant sub-circuit 1223 to obtain current through inductive coupling, and provide the required output current to the load through the output port 14.

[0081] In some embodiments, when the fourth switch group 1214 is closed, the capacitor C S4Output the second voltage to the second voltage conversion unit 13; please refer to Figure 7 The fourth switch group 1214 includes switches S4, S5 and S R4 The fourth resonant subcircuit 1224 includes a flying capacitor C F4 、Flying capacitor C F1 and inductor L C1 , flying capacitor C F4 One end of the flying capacitor C is connected to the switch S4. F1 The other end of the capacitor C S1 One end of the inductor L C1 One end of the flying capacitor C F1 One end of the flying capacitor C is connected to the switch S5. F1 The other end of the capacitor C is connected to the power transmission module 124; S1 The other end is connected to switch S5, capacitor C S1 The capacitance value is greater than the flying capacitor C F4 And the flying capacitor C F1 The capacitance value is so that the capacitor C S1 The capacitor C S1 The voltage is equal to the second voltage.

[0082] In some embodiments, when the fourth switch group 1214 is closed, the inductor L C1 The leakage inductance of L participates in the resonance, that is, not the entire inductance L C1 All will participate in resonance.

[0083] Based on the above description, it can be known that when the third switch group 1213 is closed, the capacitor C S4 Therefore, the switch S in the fourth switch group 1214 is R4 When closed, the capacitor C S4 The second voltage can be output to the second voltage conversion unit 13 .

[0084] Continuing with the above description, since the switches S4 and S5 in the fourth switch group 1214 are closed, the flying capacitor C F4 、Flying capacitor C F1 and inductor L C1 In addition, due to the capacitor C S1 The capacitance value is much larger than the flying capacitor C F4 And the flying capacitor C F1 The capacitance value, therefore, is S1 Does not participate in resonance. And the flying capacitor C F4 One end of the switch S4 is connected to the input port 11, so the flying capacitor C F4 To charge the flying capacitor C F1 Discharge. And the flying capacitor CF1 and capacitor C S1 A switch S5 is connected between them, so when the switch S58 is closed, due to the flying capacitor C F1 discharge, so that the capacitor C S1 In addition, the flying capacitor C F4 It is also connected to the power transmission module 124, so that when the fourth resonant sub-circuit 1224 is turned on, the power transmission module 124 can also receive energy from the fourth resonant sub-circuit 1224 to obtain current through inductive coupling and provide the required output current to the load through the output port 14.

[0085] In some embodiments, please refer to Figures 4 to 8 , the power transmission module 124 includes an inductor L C1 、Inductance L C2 、Inductance L C3 and inductor L C4 , inductance L C1 、Inductance L C2 、Inductance L C3 and inductor L C4 Therefore, the inductor L C1 、Inductance L C2 、Inductance L C3 and inductor L C4 A coupled inductor as a whole can be formed, so that after receiving energy from the turned-on resonant sub-circuit, the functional transmission module 124 can obtain current through the coupled inductor as a whole.

[0086] In addition, from Figures 4 to 7 As can be seen in FIG. 1 , when the first switch group 1211 is closed, the switch S R2 will be disconnected, then the inductor L C2 is not grounded, and switch S R1 , switch S R3 , switch S R4 will be closed, and accordingly, the inductance L C1 、Inductance L C3 and inductor L C4 When the second switch group 1212 is closed, the switch S R3 will be disconnected, then the inductor L C23 is not grounded, and switch S R1 , switch S R2 , switch S R4 will be closed, and accordingly, the inductance L C1 、Inductance L C2 and inductor L C4 When the third switch group 1213 is closed, the switch S R4 will be disconnected, then the inductor L C4 is not grounded, and switch SR1 , switch S R2 , switch S R3 will be closed, and accordingly, the inductance L C1 、Inductance L C2 and inductor L C3 When the fourth switch group 1214 is closed, the switch S R1 will be disconnected, then the inductor L C1 is not grounded, and switch S R2 , switch S R3 , switch S R4 will be closed, and accordingly, the inductance L C2 、Inductance L C3 and inductor L C4 It can be seen from this that for a single inductor, 75% of the time it is grounded, that is, the embodiment of the present application can increase the inductor grounding duty cycle to increase the voltage conversion ratio.

[0087] Based on the above content, it can be known that the closing time of the first switch group 1211, that is, the first phase working time is equal to 0.5 resonant cavity resonant cycle. After the first phase work is completed, all switches are closed, and the self-inductance current obtained by the power transmission module 124 charges and discharges all switch nodes, which can realize soft switching of all switches. Similarly, when the second switch group 1212 is closed, the third switch group 1213 is closed, and the fourth switch group 1214 is closed, the same is true.

[0088] In some embodiments, please refer to Figure 8 The second switching module 131 includes a switch S H1 , switch S H2 , switch S H3 , switch S H4 and switch S L ; Switch S H1 One end is used to connect the capacitor C S1 Connection, switch S H1 The other end is used to connect to the switch S L Connected to the step-down module 132; switch S H2 One end is used to connect the capacitor C S2 Connection, switch S H2 The other end is used to connect to the switch S L Connected to the step-down module 132; switch S H3 One end is used to connect the capacitor C S3 Connection, switch S H2 The other end is used to connect to the switch S L Connected to the step-down module 132; switch S H3 One end is used to connect the capacitor C S3 Connection, switch S H3The other end is used to connect to the switch S L The second switching module 131 responds to the second control signal and controls the corresponding switch in the second switching module 131 to close according to the second duty cycle, including: when the first switch group 1211 is closed, the second switching module 131 responds to the second control signal and controls the switch S according to the second duty cycle H1 and switch S L When the second switch group 1212 is closed, the second switching module 131 responds to the second control signal and controls the switch S according to the second duty cycle H2 and switch S L When the third switch group 1213 is closed, the second switching module 131 responds to the second control signal and controls the switch S according to the second duty cycle H3 and switch S L When the fourth switch group 1214 is closed, the second switching module 131 responds to the second control signal and controls the switch S according to the second duty cycle H4 and switch S L Closed; wherein the second duty cycle is determined according to the output voltage and the second voltage.

[0089] Please refer to Figure 4 , due to the switch S H1 One end is used to connect the capacitor C S1 When the first switch group 1211 is closed, the second switching module 131 responds to the second control signal and controls the switch S according to the second duty cycle. H1 and switch S L When closed, the capacitor C S1 The second voltage in itself can be passed through the switch S H1 is transmitted to the second voltage conversion unit 13. Therefore, when the first switch group 1211 is closed, the switch S H1 , switch S L can work together to convert the second voltage into the output voltage.

[0090] Please refer to Figure 5 , due to the switch S H2 One end is used to connect the capacitor C S2 When the second switch group 1212 is closed, the second switching module 131 responds to the second control signal and controls the switch S according to the second duty cycle. H2 and switch S L When closed, the capacitor C S2 The second voltage in itself can be passed through the switch S H2 is transmitted to the second voltage conversion unit 13. Therefore, when the second switch group 1212 is closed, the switch S H2 , switch S Lcan work together to convert the second voltage into the output voltage.

[0091] Please refer to Figure 6 , due to the switch S H3 One end is used to connect the capacitor C S3 When the third switch group 1213 is closed, the second switching module 131 responds to the second control signal and controls the switch S according to the second duty cycle. H3 and switch S L When closed, the capacitor C S3 The second voltage in itself can be passed through the switch S H3 is transmitted to the second voltage conversion unit 13. Therefore, when the third switch group 1213 is closed, the switch S H3 , switch S L can work together to convert the second voltage into the output voltage.

[0092] Please refer to Figure 7 , due to the switch S H4 One end is used to connect the capacitor C S4 When the fourth switch group 1214 is closed, the second switching module 131 responds to the second control signal and controls the switch S according to the second duty cycle. H4 and switch S L When closed, the capacitor C S4 The second voltage in itself can be passed through the switch S H4 is transmitted to the second voltage conversion unit 13. Therefore, when the fourth switch group 1214 is closed, the switch S H4 , switch S L can work together to convert the second voltage into the output voltage.

[0093] In some embodiments, please refer to Figures 4 to 8 The buck module 132 includes an inductor L R .

[0094] In some embodiments, the second duty cycle is determined according to the output voltage and the second voltage, and when the first switch group 1211 is closed, the second duty cycle is used to indicate that the switch S H1 and switch S L The corresponding duty ratios are respectively, when the second switch group 1212 is closed, the second duty ratio is used to indicate the switch S H2 and switch S L The corresponding duty ratios are respectively, when the third switch group 1213 is closed, the second duty ratio is used to indicate the switch S H3 and switch S L The corresponding duty ratios are respectively, when the fourth switch group 1214 is closed, the second duty ratio is used to indicate the switch S H4 and switch SL The corresponding duty cycles respectively.

[0095] For example, the first switch group 1211 is currently closed, the second voltage is 8V, and the required output voltage is 5V. Then, the switch S indicated in the second duty cycle is H1 The duty cycle of the switch S indicated in the second duty cycle is the ratio of 5 to 8, that is, 62.5%. L The duty cycle of the switch S indicated in the second duty cycle is 1 minus 62.5%, that is, 37.5%. For another example, the second switch group 1212 is currently closed, and the second voltage is 10V, and the required output voltage is 5V. H2 The duty cycle of the switch S is 50%. L The duty cycle is also 50%.

[0096] The first voltage conversion unit in the DC conversion circuit of the embodiment of the present application includes a first switching module, a resonance module, and an input capacitor module, and the resonance module includes at least two resonant sub-circuits. The first switching module can respond to the first control signal to turn on the resonant sub-circuit and charge the input capacitor module. In this way, not only can high power density voltage reduction be achieved, but also resonant soft switching and capacitor soft charging can be achieved. Moreover, by introducing a multi-phase current path, the current load capacity of the DC conversion circuit can be increased. In addition, the input capacitor module can output the second voltage stored in itself to the second voltage conversion unit. The second voltage conversion unit works in a pulse width modulation mode, that is, the second duty cycle corresponding to the second control signal can be modulated, and the second voltage is the voltage in the output voltage other than the first voltage. Therefore, the embodiment of the present application can achieve bus regulation by changing the input capacitor module to adapt to possible bus voltage fluctuations.

[0097] Please refer to Fig. 9 , Fig. 9 A DC conversion device is provided in an embodiment of the present application, and the DC conversion device includes a DC conversion circuit 1 and a control module 2. The DC conversion circuit adopts the DC conversion circuit 1 in any of the above embodiments. Since the DC conversion circuit 1 has been clearly explained in the above DC conversion circuit embodiment, it will not be repeated here. The control module 2 is used to output a first control signal and a second control signal to control the DC conversion circuit 1 to work.

[0098] In some embodiments, please refer to Fig.10The control module 2 includes multiple high-side switch driving sub-circuits 21, which are used to drive switches S1 to S8 to close or open them; the multiple high-side switch driving sub-circuits 21 each include a first energy storage sub-module 211, a first switch sub-module 212, a second switch sub-module 213, a third switch sub-module 214, a logic control sub-module 215, and a driving sub-module 216. One end of the first energy storage submodule 211 is respectively connected to the input port 11 and the first pole of the third switch submodule 214, and the other end of the first energy storage submodule 211 is used to be respectively connected to the first pole of the first switch submodule 212 and the first pole of the second switch submodule 213; the second pole of the first switch submodule 212 is used to be grounded, and the third pole of the first switch submodule 212 is used to receive the third control signal; the second pole of the second switch submodule 213 is connected to the power supply VDD, and the third pole of the second switch submodule 213 is used to receive the third control signal; the second pole of the third switch submodule 214 is respectively connected to the control end of the target switch S0 and one end of the driving submodule 216, and the third pole of the third switch submodule 214 is used to receive the fourth control signal, and the target switch S0 is the switch that currently needs to be closed among the switches S1 to S8; the receiving end of the target switch S0 is connected to the other end of the driving submodule 216, and the transmitting end of the target switch S0 is used to connect to other parts in the DC conversion circuit 1; the logic control submodule 215 is used to send the third control signal and the fourth control signal.

[0099] Among them, when the first switch submodule 212 is turned on and the second switch submodule 213 is turned off, the first energy storage submodule 211 can be charged through the input port, and the voltage of the first energy storage submodule 211 is equal to the input voltage corresponding to the input port 11; when the second switch submodule 213 is turned on and the first switch submodule 212 is turned off, the first energy storage submodule 211 can be charged through the input port and the power supply, and the voltage of the first energy storage submodule 211 is equal to the sum of the input voltage and the voltage of the power supply VDD; the third switch submodule 214 is used to select whether to charge the energy storage capacitor in the driving submodule 216.

[0100] In some embodiments, the driving submodule 216 includes not only an energy storage capacitor but also a level converter, a diode and a driver. Therefore, after the energy storage capacitor is charged, the driving submodule 216 can perform corresponding work through the level converter and the driver, and then work in conjunction with the first energy storage submodule 211 to stably drive the target switch S0.

[0101] In addition, in some embodiments, please refer to Fig.10The first energy storage submodule 211 includes a capacitor C1, the first switch submodule 212 includes a MOS tube (MOSFET, Metal Oxide Semiconductor Field Effect Transistor) Q1, the second switch submodule 213 includes a MOS tube Q2, and the third switch submodule 214 includes a MOS tube Q3.

[0102] It should be noted that the above-mentioned MOS tube Q1, MOS tube Q2, and MOS tube Q3 can be N-MOS tubes (N-Metal-Oxide-Semiconductor FET, N-type metal-oxide semiconductor field effect transistor) or P-MOS tubes (P-Metal-Oxide-Semiconductor FET, P-type metal-oxide semiconductor field effect transistor). Technicians can set them according to actual conditions, and the embodiments of the present application are not limited to this.

[0103] In some embodiments, please refer to Fig.10 The high-side switch driving subcircuit 21 further includes a logic control submodule 216 for outputting a third control signal and a fourth control signal to control the disconnection or conduction of the first switch submodule 212 , the second switch submodule 213 , and the third switch submodule 214 .

[0104] In some embodiments, the switches S1 to S8 are all high-side switches, and each switch requires a corresponding driving circuit. Therefore, the control module 2 needs to include a plurality of high-side switch driving sub-circuits 21 .

[0105] Based on the above content, it can be seen that after each phase of work is completed, all switches are closed, and the self-inductance current obtained by the power transmission module 124 charges and discharges all switch nodes, which can realize soft switching of all switches. Therefore, the high-side switch driving subcircuit 21 is a charge pump type driving circuit based on soft switching.

[0106] Taking the switch S2 in the second switch group 1212 as an example, before the second phase operation starts, VSSH3 is already equal to the input voltage. Therefore, in order to charge the bootstrap capacitor driving the switch S2, it is only necessary to use a charge pump to build a voltage rail of the input voltage (VIN) + threshold. Fig.10 As shown, before the switch S2 is turned on, the charge pump builds the VIN+threshold voltage rail and is selected by the third switch submodule 214 to power the bootstrap capacitor driving the switch to be turned on.

[0107] In some embodiments, the switch S R1 To switch S R4 Both are low side switches.

[0108] In addition, in some embodiments, each switch in the DC conversion circuit 1 needs to have a corresponding driving circuit, that is, in addition to the high-side switch driving sub-circuit 21 corresponding to switches S1 to S8, the control module 2 also needs to include driving sub-circuits corresponding to other switches.

[0109] It should be noted that the driving sub-circuits corresponding to other switch sub-circuits can be set according to actual needs, and the embodiments of the present application do not limit this.

[0110] The first voltage conversion unit in the DC conversion circuit of the embodiment of the present application includes a first switching module, a resonance module, and an input capacitor module, and the resonance module includes at least two resonant sub-circuits. The first switching module can turn on the resonant sub-circuit in response to the first control signal and charge the input capacitor module. In this way, not only can high power density voltage reduction be achieved, but also resonant soft switching and capacitor soft charging can be achieved. Moreover, the current load capacity of the DC conversion circuit can be increased by introducing a multi-phase current path. In addition, the input capacitor module can output the second voltage stored in itself to the second voltage conversion unit, and the second voltage conversion unit works in a pulse width modulation mode, that is, the second duty cycle corresponding to the second control signal can be modulated, and the second voltage is the voltage in the output voltage other than the first voltage. Therefore, the embodiment of the present application can realize bus regulation by changing the input capacitor module to adapt to possible bus voltage fluctuations. In addition, the control module includes a plurality of high-side switch driving sub-circuits. Since the high-side switch sub-circuit is a charge pump type driving circuit, and the charge pump circuits of different switches share the same flying capacitor, the use of bootstrap capacitors can be reduced.

[0111] Those skilled in the art will appreciate that all or part of the functions of the various methods in the above-mentioned embodiments can be implemented by hardware or by computer programs. When all or part of the functions in the above-mentioned embodiments are implemented by computer programs, the program can be stored in a computer-readable storage medium, and the storage medium can include: read-only memory, random access memory, disk, optical disk, hard disk, etc., and the program is executed by a computer to implement the above-mentioned functions. For example, the program is stored in the memory of the device, and when the program in the memory is executed by the processor, all or part of the above-mentioned functions can be implemented. In addition, when all or part of the functions in the above-mentioned embodiments are implemented by computer programs, the program can also be stored in a storage medium such as a server, another computer, disk, optical disk, flash disk or mobile hard disk, and can be downloaded or copied and saved in the memory of the local device, or the system of the local device is updated, and when the program in the memory is executed by the processor, all or part of the functions in the above-mentioned embodiments can be implemented.

[0112] The above specific examples are used to illustrate the present invention, which is only used to help understand the present invention and is not intended to limit the present invention. For those skilled in the art, according to the concept of the present invention, some simple deductions, modifications or substitutions can be made.

Claims

1. A DC conversion circuit, characterized in that: comprising an input port, a first voltage conversion unit, a second voltage conversion unit and an output port; The input port is used to receive an input voltage; The first voltage conversion unit is used to convert a first voltage in the input voltage into an output voltage, and output it through the output port; The first voltage conversion unit includes a first switching module, a resonance module, an input capacitor module and a power transmission module, wherein the first switching module controls one of at least two resonance sub-circuits included in the resonance module to be turned on in response to a first control signal; the input capacitor module is used to output a stored second voltage to the second voltage conversion unit, wherein the second voltage is a voltage in the input voltage other than the first voltage; the power transmission module is used to obtain current through inductive coupling, and provide a required output current to the load through the output port; The second voltage conversion unit is used to convert the second voltage into the output voltage and output it through the output port; The second voltage conversion unit includes a second switching module and a buck module. The second switching module controls the corresponding switch in the second switching module to close according to a second duty cycle in response to a second control signal, so as to cooperate with the buck module to convert the second voltage into the output voltage.

2. The DC conversion circuit according to claim 1, characterized in that: The first switching module includes a first switch group, a second switch group, a third switch group and a fourth switch group; The resonance module includes a first resonant subcircuit, a second resonant subcircuit, a third resonant subcircuit and a fourth resonant subcircuit; The input capacitor module includes a capacitor C S1 , capacitor C S2 , capacitor C S3 and capacitor C S4 ; The first switching module is specifically used for: In response to the first control signal, the first switch group, the second switch group, the third switch group and the fourth switch group are closed in sequence according to the first duty cycle corresponding to the first control signal, so as to turn on the first resonant sub-circuit, the second resonant sub-circuit, the third resonant sub-circuit and the fourth resonant sub-circuit in sequence, and the capacitor C S2 , the capacitor C S3 , the capacitor C S4 and the capacitor C S1 to charge.

3. The DC conversion circuit according to claim 2, characterized in that: When the first switch group is closed, the capacitor C S1 outputting the second voltage to the second voltage conversion unit; The first switch group includes a switch S1, a switch S6 and a switch S R1 The first resonant subcircuit includes a flying capacitor C F1 、Flying capacitor C F2 and inductor L C2 , the flying capacitor C F1 One end of the flying capacitor C is connected to the switch S1. F1 The other end of the capacitor C S2 One end of the inductor L C2 One end of the flying capacitor C F2 One end of the flying capacitor C is connected to the switch S6. F2 The other end is connected to the power transmission module; The capacitor C S2 The other end of the capacitor C is connected to the switch S6. S2 The capacitance value is greater than the flying capacitor C F1 And the flying capacitor C F2 The capacitance value is such that the capacitor C S2 is charged, so that the capacitor C S2 The voltage is equal to the second voltage.

4. The DC conversion circuit according to claim 2, characterized in that: When the second switch group is closed, the capacitor C S2 outputting the second voltage to the second voltage conversion unit; The second switch group includes a switch S2, a switch S7 and a switch S R2 The second resonant subcircuit includes a flying capacitor C F2 、Flying capacitor C F3 and inductor L C3 , the flying capacitor C F2 One end of the flying capacitor C is connected to the switch S2. F2 The other end of the capacitor C S3 One end of the inductor L C3 One end of the flying capacitor C F3 One end of the flying capacitor C is connected to the switch S7. F3 The other end is connected to the power transmission module; The capacitor C S3 The other end of the capacitor C is connected to the switch S7. S3 The capacitance value is greater than the flying capacitor C F2 And the flying capacitor C F3 The capacitance value is such that the capacitor C S3 is charged, so that the capacitor C S3 The voltage is equal to the second voltage.

5. The DC conversion circuit according to claim 2, characterized in that: When the third switch group is closed, the capacitor C S3 outputting the second voltage to the second voltage conversion unit; The third switch group includes switches S3, S8 and S R3 The third resonant subcircuit includes a flying capacitor C F3 、Flying capacitor C F4 and inductor L C4 , the flying capacitor C F3 One end of the flying capacitor C is connected to the switch S3. F3 The other end of the capacitor C S4 One end of the inductor L C4 One end of the flying capacitor C F4 One end of the flying capacitor C is connected to the switch S8. F4 The other end is connected to the power transmission module; The capacitor C S4 The other end of the capacitor C is connected to the switch S8. S4 The capacitance value is greater than the flying capacitor C F3 And the flying capacitor C F4 The capacitance value is such that the capacitor C S4 is charged, so that the capacitor C S4 The voltage is equal to the second voltage.

6. The DC conversion circuit according to claim 2, characterized in that: When the fourth switch group is closed, the capacitor C S4 outputting the second voltage to the second voltage conversion unit; The fourth switch group includes switches S4, S5 and S R4 The fourth resonant subcircuit includes a flying capacitor C F4 、Flying capacitor C F1 and inductor L C1 , the flying capacitor C F4 One end of the flying capacitor C is connected to the switch S4. F1 The other end of the capacitor C S1 One end of the inductor L C1 One end of the flying capacitor C F1 One end of the flying capacitor C is connected to the switch S5. F1 The other end is connected to the power transmission module; The capacitor C S1 The other end of the capacitor C is connected to the switch S5. S1 The capacitance value is greater than the flying capacitor C F4 And the flying capacitor C F1 The capacitance value is such that the capacitor C S1 is charged, so that the capacitor C S1 The voltage is equal to the second voltage.

7. The DC conversion circuit according to any one of claims 3 to 6, characterized in that: The power transmission module includes the inductor L C1 , the inductor L C2 , the inductor L C3 and the inductance L C4 , and the inductance L C1 , the inductor L C2 , the inductor L C3 and the inductance L C4 coupling.

8. The DC conversion circuit according to claim 1 or 2, characterized in that: The second switching module includes a switch S H1 , switch S H2 , switch S H3 , switch S H4 and switch S L ; The switch S H1 One end of the capacitor C S1 connection, the switch S H1 The other end is used to connect to the switch S L and connected to the step-down module; the switch S H2 One end of the capacitor C S2 connection, the switch S H2 The other end is used to connect to the switch S L and connected to the step-down module; the switch S H3 One end of the capacitor C S3 connection, the switch S H2 The other end is used to connect to the switch S L and connected to the step-down module; the switch S H3 One end of the capacitor C S3 connection, the switch S H3 The other end is used to connect to the switch S L Connected to the step-down module; The second switching module controls the corresponding switch in the second switching module to close according to the second duty cycle in response to the second control signal, including: When the first switch group is closed, the second switching module controls the switch S according to the second duty cycle in response to the second control signal. H1 and switch S L closure; When the second switch group is closed, the second switching module controls the switch S according to the second duty cycle in response to the second control signal. H2 and switch S L closure; When the third switch group is closed, the second switching module controls the switch S according to the second duty cycle in response to the second control signal. H3 and switch S L closure; When the fourth switch group is closed, the second switching module controls the switch S according to the second duty cycle in response to the second control signal. H4 and switch S L closure; The second duty cycle is determined according to the output voltage and the second voltage.

9. A DC conversion device, characterized in that: include: A DC conversion circuit, wherein the DC conversion circuit adopts the DC conversion circuit as described in any one of 1-8; The control module is used to output a first control signal and a second control signal to control the DC conversion circuit to work.

10. The DC conversion device according to claim 9, characterized in that: The control module also includes: A plurality of high-side switch driving subcircuits, used for driving switches S1 to S8 to close or open them; each of the plurality of high-side switch driving subcircuits comprises a first energy storage submodule, a first switch submodule, a second switch submodule, a third switch submodule, a logic control submodule and a driving submodule; One end of the first energy storage submodule is respectively connected to the input port and the first pole of the third switch submodule, and the other end of the first energy storage submodule is used to be respectively connected to the first pole of the first switch submodule and the first pole of the second switch submodule; the second pole of the first switch submodule is used to be grounded, and the third pole of the first switch submodule is used to receive a third control signal; the second pole of the second switch submodule is connected to the power supply, and the third pole of the second switch submodule is used to receive a third control signal; the second pole of the third switch submodule is respectively connected to the control end of the target switch and one end of the driving submodule, and the third pole of the third switch submodule is used to receive a fourth control signal, and the target switch is the switch that currently needs to be closed among the switches S1 to S8; the receiving end of the target switch is connected to the other end of the driving submodule, and the transmitting end of the target switch is used to connect to other parts in the DC conversion circuit; the logic control submodule is used to send the third control signal and the fourth control signal; Among them, when the first switch submodule is turned on and the second switch submodule is turned off, the first energy storage submodule can be charged through the input port, and the voltage of the first energy storage submodule is equal to the input voltage corresponding to the input port; when the second switch submodule is turned on and the first switch submodule is turned off, the first energy storage submodule can be charged through the input port and the power supply, and the voltage of the first energy storage submodule is equal to the sum of the input voltage and the voltage of the power supply; the third switch submodule is used to select whether to charge the energy storage capacitor in the driving submodule.

Images