Direct current conversion circuit and direct current conversion device

Abstract

The application discloses a direct current conversion circuit and a direct current conversion device, and belongs to the technical field of power converters. The direct current 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 a first voltage into an output voltage; the first voltage conversion unit comprises a first switching module, which controls one of at least two resonance sub-circuits included in a resonance module to be conductive in response to a first control signal; and further comprises an input capacitor module, which is used for outputting a stored second voltage to the second voltage conversion unit. The second voltage conversion unit is used for converting a second voltage into the output voltage; the second voltage conversion unit comprises a second switching module, which can control a corresponding switch to be closed in response to a second control signal, so as to work cooperatively with a voltage reduction module to convert the second voltage into the output voltage. The application can increase current load capacity while realizing high power density voltage reduction.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power converter, in particular to a direct current conversion circuit and a direct current conversion device. BACKGROUND

[0002] In recent years, with the popularization of artificial intelligence, cloud computing and Internet of Things devices and the increasing demand for high-performance computing, the power consumption of data centers has rapidly increased. Therefore, the power supply quality has an important influence on the operation 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 bear the function of converting the 48V bus voltage to low voltage and supplying power to the load point converter in the rear stage. In the related technology, 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 resonance and inductance-inductance-capacitance (LLC) resonant converters are often used in bus converter design. However, the 12V intermediate voltage puts forward higher voltage resistance requirements for the switches and passive components of the load point converter in the rear stage, reduces the quality factor of the used components and limits the efficiency and power density of the overall architecture. In order to improve the performance of the overall architecture, more work in recent years explores reducing the intermediate voltage to around 5V. However, the lower intermediate voltage requires the intermediate bus converter to provide a higher voltage conversion ratio, which increases the number of stages of the switched capacitor converter and the switched resonance converter, and increases the turns ratio of the LLC transformer, limiting its performance. Therefore, the traditional intermediate bus converter structure cannot meet the higher performance requirements, and the actual voltage value of the 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 output. SUMMARY

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

[0004] In one aspect, a direct current 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 configured to receive an input voltage;

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

[0007] The second voltage conversion unit is configured to convert the second voltage into the output voltage and output the output voltage through the output port. The second voltage conversion unit comprises a second switching module and a step-down module. The second switching module is configured to control corresponding switches in the second switching module to be closed in accordance with a second duty cycle in response to a second control signal, so as to work with the step-down module to convert the second voltage into the output voltage.

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

[0009] The resonance module comprises a first resonance sub-circuit, a second resonance sub-circuit, a third resonance sub-circuit and a fourth resonance sub-circuit.

[0010] The input capacitor module comprises a capacitor C S1 , a capacitor C S2 , a capacitor C S3 and a capacitor C S4 .

[0011] The first switching module is specifically configured to:

[0012] In response to a first control signal, sequentially close the first switch group, the second switch group, the third switch group and the fourth switch group in accordance with a first duty cycle corresponding to the first control signal, so as to sequentially conduct the first resonance sub-circuit, the second resonance sub-circuit, the third resonance sub-circuit and the fourth resonance sub-circuit, and charge the capacitor C S2 , the capacitor C S3 , the capacitor C S4 and the capacitor C S1 .

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

[0014] The first switch group comprises switches S1, S6 and S R1 The first resonant sub-circuit comprises flying capacitor C F1 , flying capacitor C F2 and inductor L C2 One end of the flying capacitor C F1 is connected with the switch S1, the other end of the flying capacitor C F1 is connected with one end of the capacitor C S2 and one end of the inductor L C2 respectively, one end of the flying capacitor C F2 is connected with the switch S6, and the other end of the flying capacitor C F2 is connected with the power transmission module.

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

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

[0017] The second switch group comprises switches S2, S7 and S R2 The second resonant sub-circuit comprises flying capacitor C F2 , flying capacitor C F3 and inductor L C3 One end of the flying capacitor C F2 is connected with the switch S2, the other end of the flying capacitor C F2 is connected with one end of the capacitor C S3 and one end of the inductor L C3 respectively, one end of the flying capacitor C F3 is connected with the switch S7, and the other end of the flying capacitor C F3 is connected with the power transmission module.

[0018] The other end of the capacitor C S3 is connected with the switch S7, and the capacitance of the capacitor C S3 is greater than that of the flying capacitor C F2 and the flying capacitor C F3 , so that the capacitor C S3 is charged, and the voltage of the capacitor C S3the voltage of the capacitor C

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

[0020] The third switch group includes switch S3, switch S8 and switch S R3 The third resonant sub-circuit includes flying capacitor C F3 , flying capacitor C F4 and inductor L C4 One end of the flying capacitor C F3 is connected to the switch S3, and the other end of the flying capacitor C F3 is connected to one end of the capacitor C S4 and one end of the inductor L C4 respectively, one end of the flying capacitor C F4 is connected to the switch S8, and the other end of the flying capacitor C F4 is connected to the power transmission module.

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

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

[0023] The fourth switch group includes switch S4, switch S5 and switch S R4 The fourth resonant sub-circuit includes flying capacitor C F4 , flying capacitor C F1 and inductor L C1 One end of the flying capacitor C F4 is connected to the switch S4, and the other end of the flying capacitor C F1 is connected to one end of the capacitor C S1 and one end of the inductor L C1 respectively, one end of the flying capacitor C F1 is connected to the switch S5, and the other end of the flying capacitor C F1 is connected to the power transmission module.

[0024] The other end of the capacitor C S1one end of the switch S S1 the capacitance of the capacitor C F4 and the flying capacitor C F1 the capacitance of the capacitor C S1 is charged, so that the voltage of the capacitor C S1 is equal to the second voltage.

[0025] Optionally, the power transmission module comprises the inductor L C1 , the inductor L C2 , the inductor L C3 and the inductor L C4 , and the inductor L C1 , the inductor L C2 , the inductor L C3 and the inductor L C4 are coupled.

[0026] Optionally, the second switching module comprises the switch S H1 , the switch S H2 , the switch S H3 , the switch S H4 and the switch S L ; one end of the switch S H1 is used for connecting with the capacitor C S1 , and the other end of the switch S H1 is used for connecting with the switch S L and the voltage reduction module respectively; one end of the switch S H2 is used for connecting with the capacitor C S2 , and the other end of the switch S H2 is used for connecting with the switch S L and the voltage reduction module respectively; one end of the switch S H3 is used for connecting with the capacitor C S3 , and the other end of the switch S H2 is used for connecting with the switch S L and the voltage reduction module respectively; one end of the switch S H3 is used for connecting with the capacitor C S3 , and the other end of the switch S H3 is used for connecting with the switch S L and the voltage reduction module respectively.

[0027] The second switching module controls the corresponding switch in the second switching module to be closed according to the second duty ratio in response to the second control signal, which comprises:

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

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

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

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

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

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

[0034] a direct current conversion circuit, which is the direct current conversion circuit as described in any of the above embodiments;

[0035] a control module, configured to output a first control signal and a second control signal to control the direct current conversion circuit to work.

[0036] Optionally, the control module further comprises:

[0037] a plurality of high-side switch driving sub-circuits, configured to drive the switches S1 to S8 to be closed or opened; each of the high-side switch driving sub-circuits comprises a first energy storage sub-module, a first switch sub-module, a second switch sub-module, a third switch sub-module, a logic control sub-module and a driving sub-module.

[0038] One end of the first energy storage submodule is connected with the input port and the first pole of the third switch submodule respectively, and the other end of the first energy storage submodule is used for being connected with the first pole of the first switch submodule and the first pole of the second switch submodule respectively; the second pole of the first switch submodule is used for being grounded, and the third pole of the first switch submodule is used for receiving a third control signal; the second pole of the second switch submodule is connected with the power supply, and the third pole of the second switch submodule is used for receiving a third control signal; the second pole of the third switch submodule is connected with the control end of the target switch and one end of the drive submodule respectively, the third pole of the third switch submodule is used for receiving a fourth control signal, and the target switch is a switch that needs to be closed in the switches S1 to S8 currently; the receiving end of the target switch is connected with the other end of the drive submodule, and the transmission end of the target switch is used for being connected with other parts in the direct current conversion circuit; the logic control submodule is used for sending the third control signal and the fourth control signal.

[0039] Wherein, 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, at this time, 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, at this time, 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 for selecting whether to charge the energy storage capacitor in the drive submodule.

[0040] The technical scheme provided in the application can bring at least the following beneficial effects:

[0041] The first voltage conversion unit in the direct current conversion circuit of the embodiment of the application comprises a first switch module, a resonance module and an input capacitor module, and the resonance module comprises at least two resonance sub-circuits, the first switch module can turn on the resonance sub-circuit and charge the input capacitor module in response to a first control signal, thus, not only can high power density be realized, but also resonance soft switching and capacitor soft charging can be realized, and in addition, the current load capacity of the direct current conversion circuit can be increased by introducing a multi-phase current path. In addition, the input capacitor module can output a second voltage stored by itself to a second voltage conversion unit, the second voltage conversion unit works in a pulse width modulation mode, that is, a second duty cycle corresponding to a second control signal can be modulated, and the second voltage is a voltage in the output voltage except the first voltage, therefore, the embodiment of the application can realize bus regulation by changing the input capacitor module to adapt to possible bus voltage fluctuation. BRIEF DESCRIPTION OF DRAWINGS

[0042] Figure 1 A structure diagram of a direct current conversion circuit provided by an embodiment of the present application is shown in FIG. 1.

[0043] Figure 2 A structure diagram of another direct current conversion circuit provided by an embodiment of the present application is shown in FIG. 2.

[0044] Figure 3 A diagram of a first duty cycle provided by an embodiment of the present application is shown in FIG. 3.

[0045] Figure 4 A structure diagram of a path corresponding to a direct current conversion circuit when a first switch group is closed provided by an embodiment of the present application is shown in FIG. 4.

[0046] Figure 5 A structure diagram of a path corresponding to a direct current conversion circuit when a second switch group is closed provided by an embodiment of the present application is shown in FIG. 5.

[0047] Figure 6 A structure diagram of a path corresponding to a direct current conversion circuit when a third switch group is closed provided by an embodiment of the present application is shown in FIG. 6.

[0048] Figure 7 A structure diagram of a path corresponding to a direct current conversion circuit when a fourth switch group is closed provided by an embodiment of the present application is shown in FIG. 7.

[0049] Figure 8 A structure diagram of another direct current conversion circuit provided by an embodiment of the present application is shown in FIG. 8.

[0050] Figure 9 A structure diagram of a direct current conversion device provided by an embodiment of the present application is shown in FIG. 9.

[0051] Figure 10 A structure diagram of a high-side switch driving sub-circuit provided by an embodiment of the present application is shown in FIG. 10. DETAILED DESCRIPTION

[0052] The present application will be further described in details through specific embodiments combined with the drawings. In different embodiments, similar elements are marked with similar element numbers. In the following embodiments, many details are described in order to make the present application better understood. However, those skilled in the art can easily recognize that some features can be omitted in different cases, 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 in order to avoid the core part of the present application being overwhelmed by too much description, and it is not necessary to describe these related operations in details for those skilled in the art according to the description in the specification and general technical knowledge in the art.

[0053] In addition, features described in the specification, operations or characteristics can be combined in any appropriate manner to form various embodiments. Meanwhile, the steps or actions in the method description can also be sequentially changed or adjusted in a manner that can be apparent 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 do not mean that the sequence is necessary, unless otherwise stated that a certain sequence must be followed.

[0054] The serial numbers of components in this paper, such as "first", "second", etc., are only used to distinguish the described objects, and have no technical meaning. The "connection" and "coupling" in this application include direct and indirect connections (couplings) unless otherwise specified.

[0055] In the related art, the traditional LLC converter realizes voltage conversion through the turns ratio of the transformer, uses the leakage inductance of the transformer to participate in resonance, and the self-inductance current helps the converter to realize complete soft switching and soft charging, and has high conversion efficiency. However, due to the increase of the turns ratio of the transformer caused by the high voltage conversion ratio, the power density of the converter is limited. For the traditional switched capacitor / resonant converter, the increase of the voltage conversion ratio increases the number of converter stages, which also increases the size and loss of the converter. Therefore, the traditional structure cannot balance the power density and conversion efficiency of the converter. And the traditional resonant converter does not have bus regulation capability in the resonant mode, that is, the traditional resonant converter works in a fixed duty cycle. Due to the fixed voltage conversion ratio, the bus and load regulation cannot be realized.

[0056] Based on this, the present application provides a direct current conversion circuit and a direct current conversion device, which can realize high power density buck, resonant soft switching and capacitor soft charging. In addition, the present application introduces a multi-phase current path to increase the current load capacity of the direct current conversion circuit. Moreover, the direct current conversion circuit in the present application introduces an input capacitor module in the first voltage conversion unit, and a second voltage conversion unit working in a pulse width modulation mode. By changing the voltage in the input capacitor module, the bus regulation is realized to adapt to possible bus voltage fluctuations. The following will be described in detail.

[0057] Please refer to Figure 1 , Figure 1is a structural schematic diagram of a direct current conversion circuit 1 provided by an embodiment of the present application. The direct current conversion circuit 1 comprises 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 configured to receive an input voltage. The first voltage conversion unit 12 is configured to convert a first voltage in the input voltage into an output voltage and output the output voltage through the output port 14; the first voltage conversion unit 12 comprises 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 is responsive to a first control signal to control one of at least two resonance sub-circuits included in the resonance module 122 to be conductive; the input capacitor module 123 is configured to output a stored second voltage to the second voltage conversion unit 13, the second voltage being a voltage other than the first voltage in the input voltage; the power transmission module 124 is configured to obtain a current through inductive coupling and provide a required output current to a load through the output port 14. The second voltage conversion unit 13 is configured to convert the second voltage into the output voltage and output the output voltage through the output port 14; the second voltage conversion unit 13 comprises a second switching module 131 and a step-down module 132, the second switching module 131 is responsive to a second control signal to control a corresponding switch in the second switching module 131 to be closed according to a second duty cycle, so as to work with the step-down module 132 to convert the second voltage into the output voltage.

[0058] That is, the first voltage conversion unit 12 converts the first voltage in the input voltage into a required output voltage, and the second voltage conversion unit 13 converts the second voltage other than the first voltage in the input voltage into a required 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 a required output voltage, that is, the direct current conversion circuit 1 is equivalent to a series input parallel output circuit. For example, assuming that a voltage conversion of 48V to 5V is required, the first voltage conversion unit 12 can perform a voltage conversion of 40V to 5V and output the obtained 5V voltage from the output port 14, and the second voltage conversion unit 13 can perform a voltage conversion of the remaining 8V to 5V and output the obtained 5V voltage from the output port 14. Thus, 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 to cause the input voltage to change, the second voltage conversion unit 13 can perform voltage conversion to enable the direct current conversion circuit 1 to adapt to a wide range of input and provide stable low-voltage output.

[0059] The first voltage conversion unit 12 comprises 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 the at least two resonance sub-circuits included in the resonance module 122 to be conductive in response to a first control signal. That is, the resonance module 122 includes at least two resonance sub-circuits, and the current load capacity of the direct current converter can be increased by introducing a multi-phase current path. The first switching module 121 can control one of the resonance sub-circuits to be conductive in response to the first control signal, so that the input capacitor module 123 can be charged, and resonance soft switching and capacitor soft charging can be achieved.

[0060] Continuing the above description, after the resonance sub-circuit is conductive, the input capacitor module 123 can be charged, so that the voltage in the input capacitor module 123 can be equal to the second voltage, and the second voltage can be output by the second voltage conversion unit 13, so that the second voltage conversion unit 13 can convert the second voltage into the required output voltage. That is, the voltage in the input capacitor module 123 can vary with the size of the input voltage. For example, assuming that the first voltage conversion unit 12 can work at 40V to 5V, if the input voltage is 48V, the corresponding voltage in the input capacitor module 123 is 8V; if the input voltage is 50V, the corresponding voltage in the input capacitor module 123 is 10V. In this way, the 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 further comprises a power transmission module 124. When the resonance sub-circuit is conductive, the power transmission module 124 can obtain current through inductive coupling, and combine the obtained current to form an output current that meets the load demand, and perform stable current output.

[0062] Based on the above description, 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 resonance sub-circuits. The second voltage conversion unit 13 further comprises a second switching module 131, and the second switching module 131 includes a plurality of switches. When the corresponding resonance sub-circuit is conductive, the second switching module 131 can control the corresponding switches to be closed in response to a second control signal and according to a second duty cycle, so that the second voltage conversion unit 13 and the step-down module 132 can work together to convert the second voltage into the output voltage.

[0063] In some embodiments, please refer to Figure 2 From Figure 2As can be seen from FIG. 1, 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 sub-circuit 1221, a second resonant sub-circuit 1222, a third resonant sub-circuit 1223, and a fourth resonant sub-circuit 1224. The input capacitance module 123 includes a capacitance C S1 , a capacitance C S2 , a capacitance C S3 , and a capacitance C S4 . The first switching module 121 is capable of, in response to the first control signal, sequentially closing the first switch group 1211, the second switch group 1212, the third switch group 1213, and the fourth switch group 1214 according to a first duty ratio corresponding to the first control signal, so as to sequentially turn on the first resonant sub-circuit 1221, the second resonant sub-circuit 1222, the third resonant sub-circuit 1223, and the fourth resonant sub-circuit 1224, and charge the capacitance C S2 , the capacitance C S3 , the capacitance C S4 , and the capacitance C S1 .

[0064] That is, the first switching module 121 is capable of, in response to the first control signal, sequentially closing 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 ratio. When the first switch group 1211 is closed, the first resonant sub-circuit 1221 is turned on, and the capacitance C S2 is capable of being charged, so as to charge the capacitance C S2 to input the second voltage for the second voltage conversion unit 13 when the second switch group 1212 is closed; when the second switch group 1212 is closed, the second resonant sub-circuit 1222 is capable of being turned on, and the capacitance C S3 is capable of being charged, so as to charge the capacitance C S3 to input the second voltage for the second voltage conversion unit 13 when the third switch group 1213 is closed; when the third switch group 1213 is closed, the third resonant sub-circuit 1223 is turned on, and the capacitance C S4 is capable of being charged, so as to charge the capacitance C S4 to input the second voltage for the second voltage conversion unit 13 when the fourth switch group 1214 is closed; when the fourth switch group 1214 is closed, the fourth resonant sub-circuit 1224 is capable of being turned on, and the capacitance C S1 is capable of being charged, so as to charge the capacitance C S1 to input the second voltage for the second voltage conversion unit 13 when the first switch group 1211 is closed.

[0065] It is to be noted that the above is that the first switching module 121 includes the first switch group 1211, the second switch group 1212, the third switch group 1213 and the fourth switch group 1214, the resonance module 122 includes the first resonant sub-circuit 1221, the second resonant sub-circuit 1222, the third resonant sub-circuit 1223 and the fourth resonant sub-circuit 1224, the input capacitance module 123 includes the capacitance C S1 , the capacitance C S2 , the capacitance C S3 and the capacitance C S4 The resonance module 122 includes the first resonant sub-circuit 1221, the second resonant sub-circuit 1222, the third resonant sub-circuit 1223 and the fourth resonant sub-circuit 1224, that is, there are four-phase current paths to be described, or, in the application, more or less current paths can be introduced according to actual needs, and the embodiments of the application do not limit this.

[0066] In some embodiments, a schematic diagram of the first duty ratio can be as shown in Figure 3 , Figure 3 The schematic diagram of the first duty ratio in a period, from Figure 3 , it can be seen that, in 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; in 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; in 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; in 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 ends work, there is a period of time in which all switch groups are in a closed state, that is, there is a dead time. The self-induction current obtained by the power transmission module 124 also charges or discharges the switch group 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 ends work, t1 value T / 4 is the dead time; after the second switch group 1212 ends work, t2 to T / 2 is the dead time; after the third switch group 1213 ends work, t3 value 3T / 4 is the dead time; after the fourth switch group 1214 ends work, t4 to T is the dead time.

[0068] It is to be noted that Figure 3The first duty cycle shown is only illustrative, and in applications, the first duty cycle can also be determined according to actual conditions, that is, the embodiments of the present application do not limit the first duty cycle.

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

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

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

[0072] Continuing the above description, since the switches S1 and S6 in the first switch group 1211 are closed, the flying capacitor C F1 , the flying capacitor C F2 and the inductor L C2 can resonate, and in addition, the capacitance of the capacitor C S2 is much greater than that of the flying capacitor C F1 and the flying capacitor CF2 The capacitance value of the flying capacitor C S2 does not participate in resonance. The flying capacitor C F1 has one end connected to the switch S1, and the other end of the switch S1 is connected to the input port 11. Thus, the flying capacitor C F1 is charged, and the flying capacitor C F2 is discharged. The flying capacitor C F2 is connected to the capacitor C S2 through the switch S6. Thus, when the switch S6 is closed, the flying capacitor C F2 is discharged, and thus the capacitor C S2 is charged. In addition, the flying capacitor C F2 is also connected to the power transmission module 124. Thus, 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 outputs the second voltage to the second voltage conversion unit 13; please refer to Figure 5 The second switch group 1212 includes the switch S2, the switch S7, and the switch S R2 The second resonant sub-circuit 1222 includes the flying capacitor C F2 , the flying capacitor C F3 , and the inductor L C3 One end of the flying capacitor C F2 is connected to the switch S2, and the other end of the flying capacitor C F2 is connected to one end of the capacitor C S3 , one end of the inductor L C3 , one end of the flying capacitor C F3 is connected to the switch S7, and the other end of the flying capacitor C F3 is connected to the power transmission module 124; the other end of the capacitor C S3 is connected to the switch S7, and the capacitance value of the capacitor C S3 is greater than the capacitance value of the flying capacitor C F2 and the flying capacitor C F3 , so that the capacitor C S3 is charged, so that the voltage of the capacitor C S3 equals the second voltage.

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

[0075] Based on the above description, when the first switch group 1211 is closed, the capacitor C S2 is able to charge. Thus, when the switch S R2 in the second switch group 1212 is closed, the capacitor C S2 is able to output the second voltage to the second voltage conversion unit 13.

[0076] Continuing the above description, since the switch S2 and the switch S7 in the second switch group 1212 are closed, the flying capacitor C F2 , the flying capacitor C F3 and the inductor L C3 are able to resonate, and in addition, since the capacitance value of the capacitor C S3 is much larger than the capacitance values of the flying capacitor C F2 and the flying capacitor C F3 , the capacitor C S3 does not participate in the resonance. And since one end of the flying capacitor C F2 is connected to the switch S2, the other end of the switch S2 is connected to the input port 11, thus the flying capacitor C F2 charges, and the flying capacitor C F3 discharges. And since the flying capacitor C F3 and the capacitor C S3 are connected by the switch S7, thus when the switch S7 is closed, since the flying capacitor C F3 discharges, the capacitor C S3 is able to charge. In addition, the flying capacitor C F3 is also connected to the power transmission module 124, thus when the second resonant sub-circuit 1222 is turned on, the power transmission module 124 is able to 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 outputs the second voltage to the second voltage conversion unit 13; please refer to Figure 6 , the third switch group 1213 includes the switch S3, the switch S8 and the switch S R3 , the third resonant sub-circuit 1223 includes the flying capacitor C F3 , the flying capacitor C F4 and the inductor L C4 , one end of the flying capacitor C F3 is connected to the switch S3, the other end of the flying capacitor C F3 is connected to one end of the capacitor C S4 , one end of the inductor L C4 respectively, one end of the flying capacitor C F4 is connected to the switch S8, and one end of the flying capacitor C F4the other end of which is connected with the power transmission module 124; and a capacitor C S4 the other end of which is connected with the switch S8, and a capacitor C S4 the capacitance of which is greater than that of the flying capacitor C F3 and the flying capacitor C F4 the capacitance of which is greater than that of the flying capacitor C S4 to be charged, so that the voltage of the capacitor C S4 is equal to the second voltage.

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

[0079] Based on the foregoing description, it can be known that the capacitor C S3 can be charged when the second switch group 1212 is closed. Thus, when the switch S R3 in the third switch group 1213 is closed, the capacitor C S3 can output the second voltage to the second voltage conversion unit 13.

[0080] Continuing the foregoing description, since the switch S3 and the switch S8 in the third switch group 1213 are closed, the flying capacitor C F3 , the flying capacitor C F4 and the inductor L C4 can participate in resonance, and since the capacitance of the capacitor C S4 is much greater than that of the flying capacitor C F3 and the flying capacitor C F4 , the capacitor C S4 does not participate in resonance. The one end of the flying capacitor C F3 is connected with the switch S3, and the other end of the switch S3 is connected with the input port 11, so the flying capacitor C F3 is charged, and the flying capacitor C F4 is discharged. The flying capacitor C F4 and the capacitor C S4 are connected with the switch S8, so when the switch S8 is closed, since the flying capacitor C F4 is discharged, the capacitor C S4 can be charged. In addition, the flying capacitor C F3 is also connected with 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 S4The second voltage is output to the second voltage conversion unit 13. Figure 7 The fourth switch group 1214 includes switch S4, switch S5 and switch S R4 The fourth resonant sub-circuit 1224 includes flying capacitor C F4 , flying capacitor C F1 and inductor L C1 One end of the flying capacitor C F4 is connected with the switch S4, and the other end of the flying capacitor C F1 is connected with one end of the capacitor C S1 , one end of the inductor L C1 respectively, one end of the flying capacitor C F1 is connected with the switch S5, and the other end of the flying capacitor C F1 is connected with the power transmission module 124; the other end of the capacitor C S1 is connected with the switch S5, and the capacitance of the capacitor C S1 is greater than that of the flying capacitor C F4 and the flying capacitor C F1 , so that the capacitor C S1 is charged, thereby making the voltage of the capacitor C S1 equal to the second voltage.

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

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

[0084] Continuing the above description, since the switch S4 and the switch S5 in the fourth switch group 1214 are closed, the flying capacitor C F4 , the flying capacitor C F1 and the inductor L C1 can resonate, and in addition, since the capacitance of the capacitor C S1 is much greater than that of the flying capacitor C F4 and the flying capacitor C F1 , the capacitor C S1 does not participate in the resonance. And one end of the flying capacitor C F4 is connected with the switch S4, and the other end of the switch S4 is connected with the input port 11, so the flying capacitor C F4 is charged, and the flying capacitor C F1 is discharged. And one end of the flying capacitor CF1 and capacitor C S1 is connected with switch S5, so when switch S5 is closed, the flying capacitor C F1 is discharged, thus the capacitor C S1 is charged. In addition, the flying capacitor C F4 is also connected with the power transfer module 124, thus when the fourth resonant sub-circuit 1224 is turned on, the power transfer 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, referring to Figures 4 to 8 , the power transfer module 124 includes inductor L C1 , inductor L C2 , inductor L C3 and inductor L C4 , inductor L C1 , inductor L C2 , inductor L C3 and inductor L C4 are coupled. Thus, inductor L C1 , inductor L C2 , inductor L C3 and inductor L C4 can constitute a coupled inductor whole, so that the power transfer module 124 can obtain current through the coupled inductor whole after receiving energy from the turned-on resonant sub-circuit.

[0086] In addition, as can be seen from Figures 4 to 7 , when the first switch group 1211 is closed, switch S R2 will be opened, so that inductor L C2 is not grounded, while switch S R1 , switch S R3 , switch S R4 are closed, and correspondingly, inductor L C1 , inductor L C3 and inductor L C4 are grounded; when the second switch group 1212 is closed, switch S R3 will be opened, so that inductor L C23 is not grounded, while switch S R1 , switch S R2 , switch S R4 are closed, and correspondingly, inductor L C1 , inductor L C2 and inductor L C4 are grounded; when the third switch group 1213 is closed, switch S R4 will be opened, so that inductor L C4 is not grounded, while switch SR1 , switch S R2 , switch S R3 will be closed, and the corresponding inductor L C1 , inductor L C2 and inductor L C3 will be grounded; when the fourth switch group 1214 is closed, the switch S R1 will be opened, and then the inductor L C1 will not be grounded, and the switch S R2 , switch S R3 , switch S R4 will be closed, and the corresponding inductor L C2 , inductor L C3 and inductor L C4 will be grounded. As can be seen, for a single inductor, there are 75% of the time in the ground, that is, the embodiment of the application can increase the voltage conversion ratio by increasing the inductor ground duty cycle.

[0087] Based on the above, the closing time of the first switch group 1211, that is, the first phase working time, is equal to 0.5 resonant cavity resonant periods, and after the first phase working is completed, all switches are closed, and the self-induction current obtained by the power transmission module 124 charges and discharges all switch nodes, so that soft switching of all switches can be realized. 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 switches S H1 , switch S H2 , switch S H3 , switch S H4 and switch S L ; one end of the switch S H1 is used to be connected with the capacitor C S1 , and the other end of the switch S H1 is used to be connected with the switch S L and the step-down module 132 respectively; one end of the switch S H2 is used to be connected with the capacitor C S2 , and the other end of the switch S H2 is used to be connected with the switch S L and the step-down module 132 respectively; one end of the switch S H3 is used to be connected with the capacitor C S3 , and the other end of the switch S H2 is used to be connected with the switch S L and the step-down module 132 respectively; one end of the switch S H3 is used to be connected with the capacitor C S3 , and the other end of the switch S H3the other end of switch S L is connected with the second voltage converting unit 13. The second switching module 131 controls the corresponding switch in the second switching module 131 to be closed according to the second duty ratio in response to the second control signal: when the first switch group 1211 is closed, the second switching module 131 controls the switch S H1 and the switch S L to be closed according to the second duty ratio in response to the second control signal; when the second switch group 1212 is closed, the second switching module 131 controls the switch S H2 and the switch S L to be closed according to the second duty ratio in response to the second control signal; when the third switch group 1213 is closed, the second switching module 131 controls the switch S H3 and the switch S L to be closed according to the second duty ratio in response to the second control signal; when the fourth switch group 1214 is closed, the second switching module 131 controls the switch S H4 and the switch S L to be closed according to the second duty ratio in response to the second control signal; wherein the second duty ratio is determined according to the output voltage and the second voltage.

[0089] Please refer to Figure 4 , since one end of the switch S H1 is connected with the capacitor C S1 , and when the first switch group 1211 is closed, the second switching module 131 controls the switch S H1 and the switch S L to be closed according to the second duty ratio in response to the second control signal, the capacitor C S1 can transmit the second voltage in itself to the second voltage converting unit 13 through the switch S H1 . Therefore, when the first switch group 1211 is closed, the switch S H1 , the switch S L can work together to convert the second voltage into the output voltage.

[0090] Please refer to Figure 5 , since one end of the switch S H2 is connected with the capacitor C S2 , and when the second switch group 1212 is closed, the second switching module 131 controls the switch S H2 and the switch S L to be closed according to the second duty ratio in response to the second control signal, the capacitor C S2 can transmit the second voltage in itself to the second voltage converting unit 13 through the switch S H2 . Therefore, when the second switch group 1212 is closed, the switch S H2 , the 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 Able to pass the second voltage in itself 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 Able to pass the second voltage in itself 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 respectively corresponding duty cycles.

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

[0096] The first voltage conversion unit in the direct current conversion circuit of the embodiment of the application comprises a first switching module, a resonance module and an input capacitor module, and the resonance module comprises at least two resonance sub-circuits, the first switching module can turn on the resonance sub-circuit in response to a first control signal and charge the input capacitor module, thus, not only can the high power density be reduced, but also the resonance soft switching and the capacitor soft charging can be realized, and the current load capacity of the direct current conversion circuit can be increased by introducing the multi-phase current path. In addition, the input capacitor module can output the second voltage stored by itself to the second voltage conversion unit, the second voltage conversion unit works in the 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 except the first voltage, therefore, the bus regulation can be realized by changing the input capacitor module in the embodiment of the application to adapt to the possible bus voltage fluctuation.

[0097] Please refer to Figure 9 , Figure 9 A direct current conversion device is provided in the embodiment of the application, and the direct current conversion device comprises a direct current conversion circuit 1 and a control module 2. The direct current conversion circuit adopts the direct current conversion circuit 1 in any one of the embodiments of the application, and the direct current conversion circuit 1 has been described in the above direct current conversion circuit embodiments, which 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 direct current conversion circuit 1 to work.

[0098] In some embodiments, please refer to Figure 10The control module 2 comprises a plurality of high-side switch driving sub-circuits 21 for driving the switches S1 to S8 to be closed or opened; each of the high-side switch driving sub-circuits 21 comprises a first energy storage sub-circuit 211, a first switch sub-circuit 212, a second switch sub-circuit 213, a third switch sub-circuit 214, a logic control sub-circuit 215, and a driving sub-circuit 216. One end of the first energy storage sub-circuit 211 is connected with the input port 11 and the first pole of the third switch sub-circuit 214, respectively, and the other end of the first energy storage sub-circuit 211 is connected with the first pole of the first switch sub-circuit 212 and the first pole of the second switch sub-circuit 213, respectively; the second pole of the first switch sub-circuit 212 is connected with the ground, and the third pole of the first switch sub-circuit 212 is used for receiving a third control signal; the second pole of the second switch sub-circuit 213 is connected with a power supply VDD, and the third pole of the second switch sub-circuit 213 is used for receiving a fourth control signal; the second pole of the third switch sub-circuit 214 is connected with the control end of a target switch S0 and one end of the driving sub-circuit 216, respectively, and the third pole of the third switch sub-circuit 214 is used for receiving a fourth control signal, the target switch S0 being a switch S1 to S8 that needs to be closed at present; the receiving end of the target switch S0 is connected with the other end of the driving sub-circuit 216, and the transmitting end of the target switch S0 is used for connecting other parts in the direct current conversion circuit 1; the logic control sub-circuit 215 is used for sending the third control signal and the fourth control signal.

[0099] In some embodiments, the driving sub-circuit 216 comprises, in addition to the energy storage capacitor, a level shifter, a diode, and a driver, so that, after the energy storage capacitor is charged, the driving sub-circuit 216 can work through the level shifter and the driver, and then work with the first energy storage sub-circuit 211 to stably drive the target switch S0.

[0100] In some embodiments, the driving sub-circuit 216 comprises, in addition to the energy storage capacitor, a level shifter, a diode, and a driver, so that, after the energy storage capacitor is charged, the driving sub-circuit 216 can work through the level shifter and the driver, and then work with the first energy storage sub-circuit 211 to stably drive the target switch S0.

[0101] In addition, in some embodiments, please refer to Figure 10The first energy storage sub-module 211 includes a capacitor C1, the first switch sub-module 212 includes a MOS tube Q1, the second switch sub-module 213 includes a MOS tube Q2, and the third switch sub-module 214 includes a MOS tube Q3.

[0102] It should be noted that the MOS tube Q1, the MOS tube Q2, and the MOS tube Q3 can be N-MOS tubes (N-Metal-Oxide-Semiconductor FETs), or can be P-MOS tubes (P-Metal-Oxide-Semiconductor FETs). The skilled person can set them according to actual conditions, and the embodiments of the present application do not limit them.

[0103] In some embodiments, referring to Figure 10 The high-side switch driving sub-circuit 21 further includes a logic control sub-module 216 configured to output a third control signal and a fourth control signal to control the first switch sub-module 212, the second switch sub-module 213, and the third switch sub-module 214 to be turned off or turned on.

[0104] In some embodiments, the switches S1 to S8 are all high-side switches, and each switch needs 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, after the work of each phase is completed, all switches are turned off, the self-induction current obtained by the power transmission module 124 charges and discharges all switch nodes, and soft switching of all switches can be achieved. Therefore, the high-side switch driving sub-circuit 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 work of the second phase starts, VSSH3 has been equal to the input voltage. Therefore, to charge the bootstrap capacitor for driving the switch S2, only a voltage rail of the input voltage (VIN) + threshold value needs to be constructed by using the charge pump. As shown in Figure 10 Before the switch S2 is turned on, the charge pump constructs the voltage rail of VIN + threshold value, and the third switch sub-module 214 selects the voltage rail to supply power to the bootstrap capacitor for driving the switch to be turned on.

[0107] In some embodiments, the switches S R1 to S R4 are low-side switches.

[0108] In addition, in some embodiments, each switch in the direct current conversion circuit 1 needs to have a corresponding driving circuit, that is, in addition to including the high-side switch driving sub-circuit 21 corresponding to the switches S1-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-circuit corresponding to other switches 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 direct current conversion circuit of the embodiments 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 resonance sub-circuits. The first switching module can turn on the resonance sub-circuit in response to a first control signal and charge the input capacitor module. In this way, not only can high power density be achieved, but also resonance soft switching and capacitor soft charging can be achieved. In addition, by introducing a multi-phase current path, the current load capacity of the direct current conversion circuit can be increased. In addition, the input capacitor module can output a second voltage stored therein to a 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. The second voltage is a voltage other than the first voltage in the output voltage. Therefore, the embodiments of the present application can achieve 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 can understand that all or part of the functions of the various methods in the above embodiments can be realized by hardware or by a computer program. When all or part of the functions in the above embodiments are realized by a computer program, the program can be stored in a computer readable storage medium, which can include read-only memory, random access memory, magnetic disk, optical disk, hard disk, etc. The above functions are realized by executing the program by a computer. For example, the program is stored in the memory of the device, and when the program in the memory is executed by the processor, the above functions are realized. In addition, when all or part of the functions in the above embodiments are realized by a computer program, the program can also be stored in a server, another computer, a storage medium such as a disk, an optical disk, a flash disk, or a mobile hard disk, and downloaded or copied into the memory of the local device, or the system of the local device is updated. When the program in the memory is executed by the processor, all or part of the functions in the above embodiments are realized.

[0112] The above application of specific examples to illustrate the present invention, is only used to help understand the present invention, and does not limit the present invention. For the skilled in the art to which the present invention belongs, according to the idea of the present invention, several simple deductions, deformation or replacement can be made.

Claims

1. A direct current conversion circuit, characterized by The direct current conversion circuit comprises an input port, a first voltage conversion unit, a second voltage conversion unit and an output port. The input port is configured to receive an input voltage. The first voltage conversion unit is configured to convert a first voltage in the input voltage into an output voltage and output the output voltage through the output port. The first voltage conversion unit comprises a first switching module, a resonance module, an input capacitor module and a power transmission module. The first switching module is configured to control one of at least two resonance sub-circuits included in the resonance module to be conductive in response to a first control signal. The input capacitor module is configured to output a stored second voltage to the second voltage conversion unit, the second voltage being a voltage other than the first voltage in the input voltage. The power transmission module is configured to obtain a current through inductive coupling and provide a required output current to a load through the output port. The second voltage conversion unit is configured to convert the second voltage into the output voltage and output the output voltage through the output port. The input capacitive module comprises a capacitor C S1 , a capacitor C S2 , a capacitor C S3 , and a capacitor C S4 ; The second voltage conversion unit comprises a second switching module and a step-down module. 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 sequentially closed according to the first duty ratio corresponding to the first control signal, so as to sequentially turn on the first resonant sub-circuit, the second resonant sub-circuit, the third resonant sub-circuit and the fourth resonant sub-circuit, and charge the capacitor C S2 , the capacitor C S3 , the capacitor C S4 and the capacitor C S1 .

2. The dc conversion circuit of claim 1, wherein, 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 comprises a switch S1, a switch S6 and a switch S R1 The first resonant sub-circuit comprises a flying capacitor C F1 , a flying capacitor C F2 and an inductor L C2 One end of the flying capacitor C F1 is connected with one end of the switch S1, the other end of the flying capacitor C F1 is connected with one end of the capacitor C S2 and one end of the inductor L C2 respectively, the other end of the switch S1 is connected with the input port, the other end of the inductor L C2 is connected with the output port, one end of the flying capacitor C F2 is connected with one end of the switch S6, and the other end of the flying capacitor C F2 is connected with the power transmission module. The other end of the capacitor C S2 is connected to the other end of the switch S6, and the capacitance of the capacitor C S2 is greater than the capacitance of the flying capacitor C F1 and the flying capacitor C F2 , so that the capacitor C S2 is charged, thereby making the voltage of the capacitor C S2 equal to the second voltage; One end of the switch S R1 is connected with the other end of the capacitor C S1 , the power transmission module, and the other end of the switch S R1 is grounded.

3. The dc conversion circuit of claim 1, wherein, 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 comprises a switch S2, a switch S7 and a switch S R2 The second resonant sub-circuit comprises a flying capacitor C F2 , a flying capacitor C F3 and an inductor L C3 One end of the flying capacitor C F2 is connected with one end of the switch S2, the other end of the flying capacitor C F2 is connected with one end of the capacitor C S3 and one end of the inductor L C3 respectively, the other end of the switch S2 is connected with the input port, the other end of the inductor L C3 is connected with the output port, one end of the flying capacitor C F3 is connected with one end of the switch S7, and the other end of the flying capacitor C F3 is connected with the power transmission module. The other end of the capacitor C S3 is connected to the other end of the switch S7, and the capacitance of the capacitor C S3 is greater than the capacitance of the flying capacitor C F2 and the flying capacitor C F3 so that the capacitor C S3 is charged, thereby making the voltage of the capacitor C S3 equal to the second voltage; One end of the switch S R2 is connected with the other end of the capacitor C S2 , the power transmission module, and the other end of the switch S R2 is grounded.

4. The dc conversion circuit of claim 1, wherein, 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 comprises a switch S3, a switch S8 and a switch S R3 The third resonant sub-circuit comprises a flying capacitor C F3 , a flying capacitor C F4 and an inductor L C4 One end of the flying capacitor C F3 is connected with one end of the switch S3, the other end of the flying capacitor C F3 is connected with one end of the capacitor C S4 and one end of the inductor L C4 respectively, the other end of the switch S3 is connected with the input port, the other end of the inductor L C4 is connected with the output port, one end of the flying capacitor C F4 is connected with one end of the switch S8, and the other end of the flying capacitor C F4 is connected with the power transmission module. The other end of the capacitor C S4 is connected to the other end of the switch S8, and the capacitance of the capacitor C S4 is greater than the capacitance of the flying capacitor C F3 and the flying capacitor C F4 so that the capacitor C S4 is charged so that the voltage of the capacitor C S4 is equal to the second voltage; One end of the switch S R3 is connected with the other end of the capacitor C S3 , the power transmission module, respectively, and the other end of the switch S R3 is grounded.

5. The dc conversion circuit of claim 1, wherein, 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 comprises a switch S4, a switch S5 and a switch S R4 The fourth resonant sub-circuit comprises a flying capacitor C F4 , a flying capacitor C F1 and an inductor L C1 One end of the flying capacitor C F4 is connected with one end of the switch S4, the other end of the flying capacitor C F4 is connected with one end of the capacitor C S1 and one end of the inductor L C1 respectively, the other end of the switch S4 is connected with the input port, the other end of the inductor L C1 is connected with the output port, one end of the flying capacitor C F1 is connected with one end of the switch S5, the other end of the flying capacitor C F1 is connected with the power transmission module; The other end of the capacitor C S1 is connected to the other end of the switch S5, and the capacitance of the capacitor C S1 is greater than the capacitance of the flying capacitor C F4 and the flying capacitor C F1 so that the capacitor C S1 is charged so that the voltage of the capacitor C S1 is equal to the second voltage; One end of the switch S R4 is connected with the other end of the capacitor C S4 , the power transmission module, and the other end of the switch S R4 is grounded.

6. A dc conversion circuit as claimed in any one of claims 2-5, characterized in that The power transfer module includes the inductor L C1 , the inductor L C2 , the inductor L C3 , and the inductor L C4 , and the inductor L C1 , the inductor L C2 , the inductor L C3 , and the inductor L C4 are coupled.

7. The dc conversion circuit of claim 1, wherein, The second switch module includes switches S H1 , S H2 , S H3 , S H4 , and S L ; one end of the switch S H1 is connected with the other end of the capacitor C S1 , the other end of the switch S H1 is connected with one end of the switch S L and the voltage reduction module respectively; one end of the switch S H2 is connected with the other end of the capacitor C S2 , the other end of the switch S H2 is connected with one end of the switch S L and the voltage reduction module respectively; one end of the switch S H3 is connected with the other end of the capacitor C S3 , the other end of the switch S H3 is connected with one end of the switch S L and the voltage reduction module respectively; one end of the switch S H4 is connected with the other end of the capacitor C S3 , the other end of the switch S H4 is connected with one end of the switch S L and the voltage reduction module respectively, and the other end of the switch S L is grounded. The second switching module is configured to control corresponding switches in the second switching module to be closed in response to a second control signal according to a second duty cycle, so as to convert the second voltage into the output voltage in cooperation with the step-down module. When the first switch group is closed, the second switch module controls the switch S H1 and the switch S L according to the second duty cycle in response to the second control signal. When the second switch group is closed, the second switch module controls the switch S H2 and the switch S L to be closed according to the second duty cycle in response to the second control signal. 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 switch module controls the switch S H4 and the switch S L to be closed according to the second duty cycle in response to the second control signal. The first switching module comprises a first switch group, a second switch group, a third switch group and a fourth switch group.

8. A DC conversion device, characterized by comprising: The resonance module comprises a first resonance sub-circuit, a second resonance sub-circuit, a third resonance sub-circuit and a fourth resonance sub-circuit. The first switching module is specifically configured to: The second switching module is configured to control corresponding switches in the second switching module to be closed according to a second duty cycle in response to a second control signal.

9. The DC conversion device of claim 8, wherein, The second duty cycle is determined according to the output voltage and the second voltage. The direct current conversion circuit comprises: The direct current conversion circuit comprises the direct current conversion circuit according to any one of claims 1-7. The control module is configured to output a first control signal and a second control signal to control the direct current conversion circuit to work. The control module further comprises: A plurality of high-side switch driving sub-circuits are configured to drive the first switching module to be closed or opened. Each of the plurality of high-side switch driving sub-circuits comprises a first energy storage sub-module, a first switch sub-module, a second switch sub-module, a third switch sub-module, a logic control sub-module and a driving sub-module. One end of the first energy storage sub-module is connected with the input port and the first pole of the third switch sub-module, respectively, and the other end of the first energy storage sub-module is used for being connected with the first pole of the first switch sub-module and the first pole of the second switch sub-module, respectively; the second pole of the first switch sub-module is used for grounding, and the third pole of the first switch sub-module is used for receiving a third control signal; the second pole of the second switch sub-module is connected with a power supply, and the third pole of the second switch sub-module is used for receiving a third control signal; the second pole of the third switch sub-module is connected with the control end of a target switch and one end of the drive sub-module, respectively, the third pole of the third switch sub-module is used for receiving a fourth control signal, and the target switch is a switch in the first switching module which needs to be closed at present; the receiving end of the target switch is connected with the other end of the drive sub-module, and the transmission end of the target switch is used for connecting other parts in the direct current conversion circuit; the logic control sub-module is used for sending the third control signal and the fourth control signal; Wherein, when the first switch sub-module is turned on and the second switch sub-module is turned off, the first energy storage sub-module can be charged through the input port, at this time, the voltage of the first energy storage sub-module is equal to the input voltage corresponding to the input port; when the second switch sub-module is turned on and the first switch sub-module is turned off, the first energy storage sub-module can be charged through the input port and the power supply, at this time, the voltage of the first energy storage sub-module is equal to the sum of the input voltage and the voltage of the power supply; the third switch sub-module is used for selecting whether to charge the energy storage capacitor in the drive sub-module.

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