Resonant driving circuit, power supply circuit, power supply and equipment

Abstract

The invention provides a resonant driving circuit, a power supply circuit, a power supply and equipment. The resonant driving circuit comprises a switching circuit, a first transformer, a detection circuit, an adjustable capacitance circuit and a control circuit. The switching circuit is electrically connected with a power supply. The first transformer is electrically connected with the switching circuit. And the detection circuit is electrically connected with the switching circuit and is used for detecting the working state of the resonant driving circuit. The adjustable capacitance circuit is electrically connected with the switching circuit and the first transformer, the adjustable capacitance circuit comprises a driving capacitor and an adjusting module, the driving capacitor is electrically connected with the adjusting module, and the adjusting module is used for adjusting an equivalent capacitance value of the adjustable capacitance circuit based on an output electric signal of the adjusting module. The output electric signal of the adjusting module comprises a current or voltage signal. The control circuit is electrically connected with the detection circuit and the adjustable module. The control circuit is used for adjusting the output electric signal of the adjusting module based on the detection result of the detection circuit. According to the invention, the resonant driving circuit can work in an optimal state.

Description

Technical Field

[0001] The present invention relates to the technical field of power supplies, and in particular to a resonant drive circuit, a power supply circuit, a power supply and equipment. Background Art

[0002] Switching power supplies are a key area of electronic technology development. As the switching frequency of the switching transistors in a switching power supply increases, the losses in the drive circuit also increase, affecting the power consumption and efficiency of the entire switching power supply. By using a resonant drive circuit to control the switching transistors in a switching power supply, the energy stored in the parasitic capacitance of the switching transistors can be recycled and reused. This effectively alleviates the slow rise and fall speed of the gate voltage of the driven switch, while also reducing inrush current and lowering drive losses.

[0003] However, in actual mass production, process limitations lead to tolerances between the parameters of various components in the resonant circuit, such as the transformer's self-inductance and the input capacitance (Ciss) of the primary and secondary MOSFETs. These variations can lead to the following problems: 1) The resonant drive circuit does not operate at its optimal point, resulting in increased losses. 2) The drive losses of each module in the switching power supply vary, resulting in poor consistency in no-load losses. Summary of the Invention

[0004] In view of this, the present application provides a resonant drive circuit, a power supply circuit, a power supply and a device to improve the problem in the prior art that the resonant circuit does not operate at the optimal point due to the tolerance between the actual value and the ideal value of the device.

[0005] In a first aspect, the present application provides a resonant drive circuit, comprising: a switching circuit, a first transformer, a detection circuit, an adjustable capacitance circuit and a control circuit. The switching circuit is electrically connected to a power supply. The first transformer is electrically connected to the switching circuit. The detection circuit is electrically connected to the switching circuit, and the detection circuit is used to detect the working state of the resonant drive circuit. The adjustable capacitance circuit is electrically connected to the switching circuit and the first transformer, respectively. The adjustable capacitance circuit comprises a driving capacitor and an adjustment module, the driving capacitor is electrically connected to the adjustment module, and the adjustment module is used to adjust the equivalent capacitance value of the adjustable capacitance circuit based on the output electrical signal of the adjustment module. The output electrical signal of the adjustment module comprises a current signal or a voltage signal. The control circuit is electrically connected to the detection circuit and the adjustable module, respectively, and the control circuit is used to adjust the output electrical signal of the adjustment module based on the detection result of the detection circuit.

[0006] The resonant drive circuit provided in this embodiment has a control circuit that can adjust the output signal of the adjustment module in the adjustable capacitor circuit based on the detection result of the detection circuit, and ultimately adjust the equivalent capacitance value of the adjustable capacitor circuit, thereby compensating for the tolerance value caused by the process in the resonant circuit, so that the equivalent inductance value and the equivalent capacitance value in the resonant circuit are in the best matching state, so that the resonant circuit operates at the optimal point, and thus the circuit can achieve the purpose of energy saving.

[0007] In one implementation of the first aspect, the resonant drive circuit includes at least two adjustable capacitance circuits, the at least two adjustable capacitance circuits include a first adjustable capacitance circuit and a second adjustable capacitance circuit, the first transformer includes a primary winding and a secondary winding, the first end of the primary winding is electrically connected to the first adjustable capacitance circuit, and the second end of the primary winding is electrically connected to the second adjustable capacitance circuit.

[0008] This implementation can be applied to the case where the switching circuit is a full-bridge circuit, or to the case where a half-bridge circuit drives multiple target switching transistors. At least two adjustable capacitor circuits can ensure the symmetry and stability of the output signal of the driving circuit.

[0009] In one implementation of the first aspect, the regulation module includes: a first transistor and at least one second transistor, the control end of the first transistor is electrically connected to the control end of the second transistor, the first end of the driving capacitor is electrically connected to the first end of the second transistor, the second end of the driving capacitor is electrically connected to the control end of the first transistor and the control end of the second transistor, respectively, the first end of the second transistor is electrically connected to the first transformer, and the first end of the first transistor is used to receive a reference current.

[0010] The first transistor and the second transistor form a current mirror. Using the scaling characteristics of the current mirror, the current flowing through the driving capacitor will be scaled accordingly in the first transistor, which is equivalent to the equivalent capacitance value of the first transistor being mi c , where m is the scaling factor of the current mirror. The first transistor and the plurality of second transistors can be integrated, thereby effectively reducing the board area occupied by the adjustable capacitor circuit.

[0011] In an implementation of the first aspect, the regulating module further includes: at least one third transistor, the first end of the second transistor is electrically connected to the first transformer through the third transistor, and the control end of the third transistor is electrically connected to the control circuit.

[0012] The control circuit turns the second transistor on and off by controlling the conduction and off-state of the third transistor. Selecting different second transistors to conduct means that the equivalent circuit of the adjustable capacitor circuit will be different. Therefore, the control circuit adjusts the equivalent capacitance of the adjustable capacitor circuit by selecting different third transistors to turn on.

[0013] In one implementation of the first aspect, the regulating module further includes: at least two second transistors and at least two third transistors. A first end of a driving capacitor is electrically connected to a first end of each second transistor, and a second end of the driving capacitor is electrically connected to a control end of each second transistor. Under control of the control circuit, at any given moment, at least one of the at least two third transistors is in an on state.

[0014] One or at least two third transistors can be allowed to be in the on state at the same time, which increases the flexibility of the optimization process and makes it easier to find the optimal equivalent capacitance value, that is, it is more conducive to the resonant drive circuit working in the best state.

[0015] In one implementation of the first aspect, the adjustment module includes: a first resistor, a second resistor, an operational amplifier, and a resistor switch array. The first end of the first resistor is electrically connected to the first end of the driving capacitor and the first transformer, respectively; the second end of the first resistor is electrically connected to the first end of the operational amplifier; the first end of the second resistor is electrically connected to the second end of the operational amplifier; and the second end of the second resistor is grounded. The resistor switch array includes at least one resistor switch branch, the first end of each resistor switch branch is electrically connected to the output end of the operational amplifier, and the second end of each resistor switch branch is electrically connected to the first end of the operational amplifier. The output end of the operational amplifier is electrically connected to the second end of the driving capacitor. The resistor switch branch includes a controllable switch and a feedback resistor connected in series, and the control end of the controllable switch is electrically connected to the control circuit.

[0016] The operational amplifier can amplify the input voltage and adjust the potential of the second end of the driving capacitor by adjusting the multiple of the operational amplifier, thereby adjusting the voltage across the driving capacitor. According to the Miller capacitance effect, the equivalent capacitance value C of the adjustable capacitor circuit is eq =(1-Av)C0.

[0017] In an implementation of the first aspect, the resistive switch array includes at least two resistive switch branches. Under the control of the control circuit, at a certain moment, at least one of the at least two resistive switch branches is in an on state.

[0018] The resistor switch array can adjust the amplification factor of the operational amplifier. Therefore, the control circuit adjusts the equivalent capacitance value of the adjustable capacitor circuit by controlling the on or off of the resistor switch branch.

[0019] In one implementation of the first aspect, the regulation module includes: a first voltage-dividing resistor, a voltage-dividing resistor switch array, a compensation resistor, and an operational amplifier, wherein the first end of the first voltage-dividing resistor is electrically connected to the first end of the operational amplifier, and the second end of the first voltage-dividing resistor is grounded. The voltage-dividing resistor switch array includes at least one voltage-dividing resistor switch branch, the first end of each voltage-dividing resistor switch branch is electrically connected to the first end of the first voltage-dividing resistor, the second end of each voltage-dividing resistor switch branch is electrically connected to the first end of the driving capacitor and the first transformer, and each voltage-dividing resistor switch branch includes a controllable switch and a voltage-dividing resistor connected in series. The second end of the driving capacitor is electrically connected to the output end of the operational amplifier, the first end of the operational amplifier is electrically connected to the output end of the operational amplifier, the second end of the operational amplifier is grounded to the first end of the compensation resistor, and the second end of the compensation resistor is grounded.

[0020] The operational amplifier can amplify the input voltage and adjust the potential of the second end of the driving capacitor by adjusting the multiple of the operational amplifier, thereby adjusting the voltage across the driving capacitor. According to the Miller capacitance effect, the equivalent capacitance value C of the adjustable capacitor circuit is eq =(1-Av)C0.

[0021] In an implementation of the first aspect, the voltage-dividing resistor switch array includes at least two voltage-dividing resistor switch branches. Under the control of the control circuit, at a certain moment, at least one of the at least two resistor switch branches is in an on state.

[0022] The voltage-dividing resistor switch branch can adjust the amplification factor of the operational amplifier. Therefore, the control circuit adjusts the equivalent capacitance value of the adjustable capacitor circuit by controlling the on or off state of the voltage-dividing resistor switch branch.

[0023] In an implementation of the first aspect, the regulating module further includes: a second transformer, wherein a primary side of the second transformer is electrically connected to the first transformer, and a secondary side of the second transformer is electrically connected to the driving capacitor.

[0024] The output of the driving capacitor can be adjusted through the transformer. Different ratios of the primary and secondary sides of the transformer will result in different equivalent capacitances on the primary side. Therefore, by adjusting the ratio of the primary and secondary windings, the equivalent capacitance of the adjustable capacitor circuit can be adjusted.

[0025] In one implementation of the first aspect, the second transformer includes: a first primary side and a first secondary side, the first primary side and the first secondary side share a magnetic core, the first end of the first primary side is electrically connected to the first transformer, the second end of the first primary side is grounded, at least one tap is provided on the first secondary side, the first end of the first secondary side is grounded, the second end of the first secondary side is electrically connected to the first end of the driving capacitor through a corresponding controllable switch, each tap of the first secondary side is electrically connected to the first end of the driving capacitor through a one-to-one corresponding controllable switch, and the second end of the driving capacitor is grounded.

[0026] The secondary side tap can effectively reduce the area of the transformer, reduce the number of secondary side terminals, and reduce the process difficulty and production cost.

[0027] In one implementation of the first aspect, the second transformer includes: a second primary side and at least two second secondary sides, the second primary side and the at least two second secondary sides share a magnetic core, the first end of the second primary side is electrically connected to the first transformer, the second end of the second primary side is grounded, the first end of each second secondary side is grounded, the second end of each second secondary side is electrically connected to the first end of the driving capacitor through a one-to-one corresponding controllable switch, and the second end of the driving capacitor is grounded.

[0028] Multiple secondary sides can ensure that when a fault occurs in one secondary side, the other secondary sides will not be affected, thereby improving the stability of the drive circuit.

[0029] In one implementation of the first aspect, the second transformer includes: a third primary side and a third secondary side, the third primary side and the third secondary side share a magnetic core, at least one tap is provided on the third primary side, the first end of the third primary side is grounded, the second end of the third primary side is electrically connected to the first transformer through a corresponding controllable switch, each tap of the third primary side is electrically connected to the first transformer through a one-to-one corresponding controllable switch, the first end of the third secondary side is grounded, the second end of the third secondary side is electrically connected to the first end of the driving capacitor, and the second end of the driving capacitor is grounded.

[0030] The primary tap can effectively reduce the area of the transformer, reduce the number of primary terminals, and reduce the process difficulty and production cost.

[0031] In one implementation of the first aspect, the second transformer includes: a fourth secondary side and at least two fourth primary sides, the first end of each fourth primary side is grounded, the second end of each fourth primary side is electrically connected to the first transformer through a one-to-one corresponding controllable switch, the first end of the fourth secondary side is grounded, the second end of the fourth secondary side is electrically connected to the first end of the driving capacitor, and the second end of the driving capacitor is grounded.

[0032] Multiple primary sides can ensure that when one primary side fails, the other primary sides can still work normally, thereby improving the stability of the drive circuit.

[0033] In a second aspect, the present application provides a power supply circuit, which includes the resonant drive circuit and the power conversion circuit of the first aspect, and the power conversion circuit is driven by the resonant drive circuit.

[0034] The present application provides a power supply circuit, whose resonant drive circuit can optimize itself so that the resonant drive circuit operates in the best state, and the switching granularity during the optimization process is small and the no-load consistency is good. Therefore, the power supply circuit has good stability and low power consumption.

[0035] In a third aspect, the present application provides a power supply, which includes the power supply circuit of the second aspect.

[0036] With the power supply provided in the present application, the resonant drive circuit inside the power supply has a good tolerance compensation effect, so that the resonant drive circuit works in an optimal state, thereby achieving the purpose of saving power consumption.

[0037] In a fourth aspect, the present application provides a device, which includes the power supply circuit of the second aspect, or the device includes the power supply of the third aspect.

[0038] The device provided in this application can ensure that the driving circuit of the electronic device operates in an optimal state, thereby achieving the purpose of reducing power consumption.

[0039] The resonant drive circuit provided in the present application has a control circuit that can adjust the output signal of the adjustment module in the adjustable capacitor circuit based on the detection result of the detection circuit, and ultimately adjust the equivalent capacitance value of the adjustable capacitor circuit, thereby compensating for the tolerance caused by the process in the resonant circuit, so that the equivalent inductance value and the equivalent capacitance value in the resonant circuit are in the best matching state, so that the resonant circuit operates at the optimal point, thereby enabling the circuit to achieve the purpose of energy saving. In addition, since the resonant drive circuit operates in the optimal state, the driving loss of each module in the switching power supply can be made almost consistent, thereby making the no-load loss highly consistent. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0041] Figure 1 A schematic diagram of a resonant drive circuit provided in an embodiment of the present application;

[0042] Figure 2 A schematic diagram of an equivalent capacitance value of an adjustable capacitance circuit in a resonant drive circuit provided in an embodiment of the present application;

[0043] Figure 3 A schematic diagram of an adjustable capacitor circuit provided in an embodiment of the present application;

[0044] Figure 4 A schematic diagram of a resonant drive circuit for optimizing based on a current source provided in an embodiment of the present application;

[0045] Figure 5 A schematic diagram of an adjustable capacitor circuit provided in an embodiment of the present application;

[0046] Figure 6 A schematic diagram of a resonant drive circuit for optimization based on an operational amplifier provided in an embodiment of the present application;

[0047] Figure 7 A schematic diagram of an adjustable capacitor circuit provided in an embodiment of the present application;

[0048] Figure 8 A schematic diagram of a resonant drive circuit for optimization based on an operational amplifier provided in an embodiment of the present application;

[0049] Figure 9 A schematic diagram of a transformer-based resonant drive circuit for optimization according to an embodiment of the present application;

[0050] Figure 10 A schematic diagram of a transformer-based resonant drive circuit for optimization according to an embodiment of the present application;

[0051] Figure 11 A schematic diagram of a transformer-based resonant drive circuit for optimization according to an embodiment of the present application;

[0052] Figure 12 A schematic diagram of a transformer-based resonant drive circuit for optimization according to an embodiment of the present application;

[0053] Figure 13 A schematic diagram of a power supply circuit provided in an embodiment of the present application.

[0054] Description of labels

[0055] 100, resonant drive circuit; 110, switching circuit; 120, first transformer; 130, detection circuit; 140, adjustable capacitor circuit; 141, regulation module; 1411, first transistor; 1412, second transistor; 1413, third transistor; 150, control circuit. DETAILED DESCRIPTION

[0056] In order to better understand the technical solution of the present application, the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0057] It should be clear that the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0058] The terms used in the embodiments of the present application are for the purpose of describing specific embodiments only and are not intended to limit the present application. The singular forms "a", "an", "the" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise.

[0059] It should be understood that the term "and / or" as used herein simply describes a relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A alone, A and B together, or B alone. Furthermore, the character " / " in this document generally indicates an "or" relationship between the associated objects.

[0060] In power modules, as switching frequency increases, drive losses also increase, further increasing power consumption and reducing efficiency. By adopting a resonant drive approach in the power module, the energy of the input capacitor of the controlled switch can be recycled and reused, effectively mitigating the rise and fall slopes of the drive voltage, reducing inrush current, and lowering drive losses.

[0061] However, in actual mass production, tolerances often exist between the parameters of different components in the resonant circuit, causing the resonant circuit to not operate at its optimal point. Therefore, drive optimization is necessary. This involves finding the optimal capacitance value during the operation of the resonant drive circuit to compensate for the tolerances between the parameters of each component, thereby adjusting the resonant frequency of the drive circuit to near the optimal frequency. At the same time, since the resonant drive circuit operates in an optimal state, the drive circuit's drive losses can be reduced and the no-load loss consistency of the power module can be improved.

[0062] To achieve the above objectives, existing optimization schemes can be roughly divided into two situations: one is to use a set of switching capacitor arrays to change the equivalent capacitance value of the resonant circuit. However, the switching capacitor array has the problem of large board area and high cost of multiple capacitors; the other is to use piezoelectric effect ceramic capacitors or MOS (metal-oxide-semiconductor) varactors to change the equivalent capacitance value in the resonant circuit. However, piezoelectric effect ceramic capacitors or MOS varactors have a small adjustable capacitance range and are easily affected by other factors, so their optimization effect is not good.

[0063] See also Figure 1, the present application provides a resonant drive circuit 100, including: a switching circuit 110, a first transformer 120, a detection circuit 130, an adjustable capacitance circuit 140 and a control circuit 150. Among them, the switching circuit 110 is used to be electrically connected to a power supply, and the switching circuit 110 is used to convert the received direct current into alternating current to supply power to the primary side of the first transformer 120. The first transformer 120 is electrically connected to the switching circuit 110, and the first transformer 120 is isolated by coupling its own primary and secondary sides, and provides power to the secondary side; at the same time, the first transformer 120 also provides inductance for the resonant circuit. For example, when the resonant circuit loop includes the primary side of the first transformer 120, the input capacitance of the target switch tube, the driving capacitance, the output capacitance of the switching circuit 110, etc., the primary side of the first transformer 120 is the main inductor in the resonant circuit. The detection circuit 130 is electrically connected to the switching circuit 110. The detection circuit 130 is used to detect the working state of the resonant drive circuit 100. The detection result of the detection circuit 130 can be used to determine whether the resonant circuit is operating in the optimal state, that is, whether the resonant circuit is operating at the optimal frequency or near the optimal frequency. The detection result of the detection circuit 130 provides a basis for whether the adjustable capacitor circuit 140 needs to adjust its equivalent capacitance value. The adjustable capacitor circuit 140 is electrically connected to the switching circuit 110 and the first transformer 120 respectively. The adjustable capacitor circuit 140 includes a driving capacitor and an adjustment module 141. The driving capacitor is electrically connected to the adjustment module 141. The adjustment module 141 is used to adjust the equivalent capacitance value of the adjustable capacitor circuit 140 based on the output electrical signal of the adjustment module 141. The equivalent capacitance value of the adjustable capacitor circuit is related to the capacitance value of the driving capacitor. The output electrical signal of the adjustment module 141 includes a current signal or a voltage signal. The equivalent capacitance value of the adjustable capacitor circuit 140 changes with the change of the output signal of the adjustment module 141. The control circuit 150 is electrically connected to the detection circuit 130 and the adjustable module respectively. The control circuit 150 is used to adjust the output electrical signal of the adjustment module 141 based on the detection result of the detection circuit 130 .

[0064] In this embodiment, when the detection result of the detection circuit 130 indicates that the resonant circuit is not operating in an optimal state, the control circuit 150 adjusts the adjustment module 141 to change the output signal, thereby changing the equivalent capacitance value of the adjustable capacitance circuit 140. When the detection result of the detection circuit 130 indicates that the resonant circuit is operating in an optimal state, the control circuit 150 maintains the current output of the adjustment module 141.

[0065] The resonant drive circuit 100 provided in the present application has a control circuit 150 that can adjust the output signal of the adjustment module 141 in the adjustable capacitor circuit 140 based on the detection result of the detection circuit 130, and ultimately adjust the equivalent capacitance value of the adjustable capacitor circuit 140, thereby compensating for the tolerance value caused by the process in the resonant circuit, so that the equivalent inductance value and the equivalent capacitance value in the resonant circuit are in the best matching state, so that the resonant circuit operates at the optimal point, and thus the circuit can achieve the purpose of energy saving.

[0066] In one embodiment of the present application, detection circuit 130 is used to detect the current, voltage, or power of the resonator drive circuit. For example, detection circuit 130 is electrically connected to the input terminal of switching circuit 110. Detection circuit 130 is used to detect the current, voltage, or power of the input circuit of switching circuit 110. The purpose of detection circuit 130 is to detect the drive loss of resonant drive circuit 100.

[0067] In one embodiment of the present application, the switch circuit 110 may be a full-bridge circuit or a half-bridge circuit or other types of switch circuits 110 with clamping. The full-bridge circuit or the half-bridge circuit has the advantages of simple structure and easy to realize the inversion effect. Figure 2 As shown, the switch circuit 110 is a full-bridge circuit, wherein Ceq is the equivalent capacitance value of the adjustable capacitance circuit.

[0068] See also Figure 2 In one embodiment of the present application, the resonant drive circuit 100 includes at least two adjustable capacitor circuits 140, the at least two adjustable capacitor circuits 140 include a first adjustable capacitor circuit 140 and a second adjustable capacitor circuit 140, the first transformer 120 includes a primary winding and a secondary winding, the first end of the primary winding is electrically connected to the first adjustable capacitor circuit 140, and the second end of the primary winding is electrically connected to the second adjustable capacitor circuit 140.

[0069] See also Figure 2 In one possible implementation, this embodiment can be applied to the case where the switching circuit 110 is a full-bridge circuit. When the switching circuit 110 is a full-bridge circuit, the two output ends of the full-bridge circuit are electrically connected to the two ends of the primary winding of the first transformer 120, and one of the two ends of the primary winding of the first transformer 120 is electrically connected to the first adjustable capacitor circuit 140, and the other is electrically connected to the second adjustable capacitor circuit 140. Therefore, it can be ensured that the full-bridge circuit has a corresponding adjustable capacitor circuit 140 to optimize the tolerance during the entire process of outputting alternating current. In another implementation, this embodiment can also be applied to the case where the switching circuit is a half-bridge circuit and the drive circuit drives multiple target switch tubes, so as to ensure that the drive signal emitted by the drive circuit has sufficient drive capability, thereby ensuring the normal operation of the target switch tubes.

[0070] See also Figure 3 In one embodiment of the present application, the output signal of the regulation module 141 is a current signal, and the control circuit 150 adjusts the output current of the regulation module 141 to change. The regulation module 141 is used to connect to an external reference current source and includes a plurality of transistors. The control module adjusts the output current of the regulation module 141 by controlling the conduction or shutdown of the plurality of transistors.

[0071] See also Figure 3 In this embodiment, the output current of the regulating module 141 can be changed by a current mirror. Figure 4 , its specific implementation method can be: the regulation module 141 includes: a first transistor 1411 and at least one second transistor 1412, the control end of the first transistor 1411 is electrically connected to the control end of the second transistor 1412, the first end of the driving capacitor is electrically connected to the first end of the second transistor 1412, the second end of the driving capacitor is electrically connected to the control end of the first transistor 1411 and the control end of the second transistor 1412 respectively, the first end of the second transistor 1412 is electrically connected to the first transformer 120, and the first end of the first transistor 1411 is used to receive a reference current.

[0072] See also Figure 4 In this embodiment, the first transistor 1411 is used to receive a reference current. The first transistor 1411 and the second transistor 1412 form a current mirror, so that the current flowing through the second transistor 1412 is m times the current flowing through the first transistor 1411. m is the scaling factor of the current mirror, that is, the ratio of the width-to-length ratio of the second transistor 1412 to the width-to-length ratio of the first transistor 1411. The self-contained voltage of the reference current causes the corresponding current mirror to be in a conducting state, and the current i flowing through the driving capacitor c Since the first transistor 1411 conducts through the channel, due to the characteristics of the current mirror, the current i c will be scaled in the second transistor 1412, that is, the current makes the current generated by the first transistor 1411 be mi c At this time, the current flowing through the main circuit of the adjustable capacitor circuit 140 becomes (m+1). If the adjustable capacitor circuit 140 at this time is equivalent to the capacitor C eq , we can get C eq The value of is (m+1)C0, where C0 is the capacitance value of the driving capacitor.

[0073] See also Figure 4 By controlling the conduction status of the plurality of second transistors 1412 , the current flowing through the regulating module 141 can be effectively adjusted, thereby adjusting the equivalent capacitance value of the adjustable capacitor circuit 140 .

[0074] In one embodiment of the present application, at least two of the plurality of second transistors 1412 have unequal width-to-length ratios. That is, the plurality of second transistors 1412 include a first sub-transistor and a second sub-transistor, wherein the width-to-length ratio of the first sub-transistor is unequal to the width-to-length ratio of the second sub-transistor. At least two of the plurality of second transistors 1412 have unequal width-to-length ratios, i.e., the scaling factors of the current mirrors formed by the two transistors and the first transistor 1411 are unequal. Therefore, the diversity of the equivalent capacitance values of the adjustable capacitor circuit 140 can be increased, making it easier to optimize.

[0075] See also Figure 4 In one embodiment of the present application, the regulation module 141 further includes: at least one third transistor 1413, the first end of the second transistor 1412 is electrically connected to the first transformer 120 through the third transistor 1413, and the control end of the third transistor 1413 is electrically connected to the control circuit 150. The third transistor 1413 is used to control the second transistor 1412 to receive an input signal, wherein the input signal can be an output signal of the primary side of the transformer. For example, the third transistor 1413 is in an on or off state under the control of the control circuit 150. When the third transistor 1413 is in an on state, the second transistor 1412 receives the input signal, and when the third transistor 1413 is in an off state, the second transistor 1412 cannot receive the input signal. In one possible implementation, the number of third transistors in the regulation module is equal to the number of second transistors, and the second transistors are electrically connected to the third transistors in a one-to-one correspondence.

[0076] See also Figure 4 In one embodiment of the present application, the regulating module 141 further includes: at least two second transistors 1412 and at least two third transistors 1413. The first end of the driving capacitor is electrically connected to the first end of each second transistor 1412, and the second end of the driving capacitor is electrically connected to the control end of each second transistor 1412. Under the control of the control circuit 150, at any given moment, at least one of the at least two third transistors 1413 is in an on state.

[0077] Under the control of the control circuit 150, one or at least two third transistors 1413 can be allowed to be in the on state at the same time, which increases the flexibility of the optimization process and makes it easier to find the optimal equivalent capacitance value, that is, it is more conducive to the resonant drive circuit 100 operating in the best state.

[0078] For example, under the control of the control circuit 150 , only one third transistor 1413 is in the on state at a certain moment, that is, the tolerance can be compensated by only one second transistor 1412 .

[0079] For example, under the control of the control circuit 150 , at least two third transistors 1413 are in the on state at a certain moment, and the control circuit 150 needs to control the two second transistors 1412 to compensate for the tolerance.

[0080] For example, under the control of the control circuit 150, only one third transistor 1413 is in the on state at a certain moment, and at another moment, at least two third transistors 1413 are in the on state. That is, the control circuit 150 can control one or more third transistors 1413 to be turned on at a time, which increases the flexibility of optimization and facilitates the resonant drive circuit 100 to operate at or near the optimal resonant frequency.

[0081] For example, under the control of the control circuit 150, when one of the at least two third transistors 1413 is in the on state, the remaining third transistors 1413 are all in the off state. That is, the control circuit 150 can only control one third transistor 1413 to be in the on state at a time. Therefore, the control difficulty of the control circuit 150 is reduced.

[0082] The first transistor 1411 , the second transistor 1412 , and the third transistor 1413 may be integrated into one integrated circuit, thereby effectively reducing the board area. Furthermore, the switching granularity of the equivalent capacitance value may be adjusted by adjusting the number of conductive portions of the third transistor 1413 .

[0083] See also Figure 5 In one embodiment of the present application, the regulating module 141 outputs a voltage signal. Under the control of the control circuit 150, the regulating module 141 changes the voltage across the driving capacitor, thereby changing the equivalent capacitance of the adjustable capacitor circuit 140.

[0084] See also Figure 5 In this embodiment, the adjustment module 141 can change the voltage signal through an operational amplifier. The operational amplifier can amplify the input voltage and adjust the potential of the second end of the driving capacitor by adjusting the multiple of the operational amplifier, thereby adjusting the voltage across the driving capacitor. According to the Miller capacitance effect, the equivalent capacitance value C of the adjustable capacitor circuit 140 is eq =(1-Av)C0, where Av is the amplification factor.

[0085] See also Figure 6In one implementation, the adjustment module 141 includes: a first resistor R1, a second resistor Rg, an operational amplifier, and a resistor switch array. The first end of the first resistor R1 is electrically connected to the first end of the driving capacitor and the first transformer 120, respectively; the second end of the first resistor R1 is electrically connected to the first end of the operational amplifier; the first end of the second resistor Rg is electrically connected to the second end of the operational amplifier; and the second end of the second resistor Rg is grounded. The resistor switch array includes at least one resistor switch branch, the first end of each resistor switch branch is electrically connected to the output end of the operational amplifier, and the second end of each resistor switch branch is electrically connected to the first end of the operational amplifier. The output end of the operational amplifier is electrically connected to the second end of the driving capacitor. The resistor switch branch includes a controllable switch and a feedback resistor connected in series, and the control end of the controllable switch is electrically connected to the control circuit 150.

[0086] In this embodiment, the operational amplifier is an inverting operational amplifier, and Av = -Rf / R1, where Rf is the total equivalent resistance of the on-state resistor switch branches in the resistor switch array. Switch control circuit 150 adjusts the value of Rf by controlling the on / off state of the resistor switch branches.

[0087] In one possible implementation, the resistive switch array includes at least two resistive switch branches. Under the control of the control circuit 150, at any given moment, at least one of the at least two resistive switch branches is in an on state. The ability of the control circuit 150 to control at least one resistive switch branch to be in an on state at a time effectively adjusts switching granularity and optimizes flexibility.

[0088] For example, under the control of the control circuit 150, at a certain moment, one of the at least two resistive switch branches is in the on state. At this moment, the control circuit 150 controls one resistive switch branch to be in the on state at a time. Controlling one resistive switch branch at a time can reduce the complexity and design difficulty of the control circuit 150.

[0089] For example, under the control of the control circuit 150, at a certain moment, at least two of the at least two resistance switch branches are in an on state. At this moment, the control circuit 150 controls the at least two resistance switch branches to be in an on state at a single time. When the two resistance branches are in an on state, their equivalent resistance values are less than the resistance value of any other resistance branch. Therefore, the control circuit 150 controls the at least two resistance branch switches to be in an on state at a single time, which can effectively reduce the switching granularity of the equivalent capacitance value of the adjustable capacitor circuit 140.

[0090] For example, under the control of the control circuit 150, at a certain moment, one of the at least two resistive switch branches is in the on state; at another moment, at least two of the at least two resistive switch branches are in the on state. That is, the control circuit 150 can simultaneously control a single resistive switch branch to be in the on state, or control at least two resistive switch branches to be in the on state.

[0091] For example, under the control of the control circuit 150, when one of the at least two resistive switch branches is in the on state, the remaining resistive switch branches are all in the off state. That is, the control circuit 150 can only control one resistive switch branch to be in the on state at a time, which can effectively reduce the control difficulty of the control circuit 150.

[0092] See also Figure 7 In another possible implementation, the adjustment module 141 includes: a first voltage-dividing resistor R1, a voltage-dividing resistor switch array, a compensation resistor Rg, and an operational amplifier. The first end of the first voltage-dividing resistor R1 is electrically connected to the first end of the operational amplifier, and the second end of the first voltage-dividing resistor R1 is grounded. The voltage-dividing resistor switch array includes at least one voltage-dividing resistor switch branch, the first end of each voltage-dividing resistor switch branch is electrically connected to the first end of the first voltage-dividing resistor R1, and the second end of each voltage-dividing resistor switch branch is electrically connected to the first end of the driving capacitor and the first transformer 120, respectively. Each voltage-dividing resistor switch branch includes a controllable switch and a voltage-dividing resistor connected in series. The second end of the driving capacitor is electrically connected to the output end of the operational amplifier, the first end of the operational amplifier is electrically connected to the output end of the operational amplifier, the second end of the operational amplifier is grounded to the first end of the compensation resistor Rg, and the second end of the compensation resistor Rg is grounded.

[0093] In this implementation, the first voltage divider resistor R1 divides the voltage with the voltage divider resistor switch array. In this implementation, the operational amplifier is an inverting operational amplifier with an amplification factor of Where R1 is the resistance of the first voltage divider resistor R1, and R2 is the equivalent resistance of the voltage divider resistor switch array. The control circuit 150 adjusts the output voltage of the adjustment module 141 by controlling the conduction state of the voltage divider resistor switch branch.

[0094] In one possible implementation, the voltage-divider resistor switch array includes at least two voltage-divider resistor switch branches. Under the control of the control circuit 150, at any given moment, at least one of the at least two resistor switch branches is in an on state. The control circuit 150 can control the controllable switch in at least one voltage-divider resistor branch to be in an on state at a single time.

[0095] For example, under the control of the control circuit 150, at a certain moment, one of the at least two resistive switch branches is in the on state, that is, at this moment, the control circuit 150 controls one resistive switch branch to be turned on at a time.

[0096] For example, under the control of the control circuit 150, at a certain moment, at least two of the at least two resistor switch branches are in an on state. That is, at that moment, the control circuit 150 controls at least two of the at least two resistor switch branches to be on at a time. The at least two resistor switch branches being on will make the equivalent resistance of the voltage-dividing resistor switch array smaller than the resistance of any one of the resistor switch branches, thereby effectively reducing switching granularity.

[0097] For example, under the control of the control circuit 150, at a certain moment, one of the at least two resistive switch branches is in the on state; at another moment, at least two of the at least two resistive switch branches are in the on state. That is, the control circuit 150 can control one or more resistive switch branches to be in the on state at a time, increasing flexibility in the optimization process.

[0098] For example, under the control of the control circuit 150, when one of the at least two resistive switch branches is in an on state, the remaining resistive switch branches are all in an off state. The control circuit 150 can only control one resistive switch branch to be in an on state at a time. Therefore, the control difficulty of the control circuit 150 is relatively low and easy to implement.

[0099] Operational amplifiers are easy to integrate, and the controllable switches in the resistor switch array or the voltage divider resistor switch array can be integrated into an integrated circuit, thereby effectively reducing the board area. By selecting the conductive branch, the switching granularity in the optimization process can be reduced.

[0100] Based on the aforementioned embodiments, it can be seen that regardless of whether a current source is used to change the output current of the regulation module 141 or an operational amplifier is used to change the output voltage of the regulation module 141, the resonant drive circuit 100 only leaves one driving capacitor on the board, and the operational amplifier, current mirror and corresponding switch can all be integrated into the IC, thereby effectively reducing the board area. Since the scaling factor of the current mirror and the amplification factor of the operational amplifier can be flexibly adjusted, the granularity of the switching capacitor capacitance adjustment is greatly reduced, which is beneficial to improving the module efficiency.

[0101] See also Figure 8 In addition to using an operational amplifier, the regulation module 141 can also use a transformer to regulate the output voltage. The transformer has a simple structure and low cost. At the same time, the transformer is a passive device with low loss and high efficiency.

[0102] See also Figures 9 to 12 In one embodiment of the present application, the regulating module 141 further includes: a second transformer. The primary side of the second transformer is electrically connected to the first transformer 120, and the secondary side of the second transformer is electrically connected to the driving capacitor. The regulating module 141 adjusts the output voltage signal by adjusting the turn ratio between the primary side of the second transformer connected to the resonant circuit and the secondary side connected to both ends of the driving capacitor, thereby achieving the purpose of adjusting the equivalent capacitance value of the adjustable capacitor circuit 140. The voltage of the primary side of the second transformer connected to the resonant circuit is V in The number of turns of the coil connected to the resonant circuit of the second transformer primary side is N1, and the voltage across the driving capacitor is V out , the number of turns of the coil connected from the secondary side of the second transformer to both ends of the driving capacitor is N2, then:

[0103] According to the law of conservation of energy, we can know that:

[0104]

[0105] Right now,

[0106]

[0107] Thus, the equivalent capacitance of the adjustable capacitance circuit 140 is obtained

[0108] See also Figure 9 In one possible implementation, the second transformer includes: a first primary side and a first secondary side, the first primary side and the first secondary side share a magnetic core, the first end of the first primary side is electrically connected to the first transformer 120, the second end of the first primary side is grounded, at least one tap is provided on the first secondary side, the first end of the first secondary side is grounded, the second end of the first secondary side is electrically connected to the first end of the driving capacitor through a corresponding controllable switch, each tap of the first secondary side is electrically connected to the first end of the driving capacitor through a one-to-one corresponding controllable switch, and the second end of the driving capacitor is grounded.

[0109] In this implementation, the first primary side is fully connected to the resonant circuit, and part of the first secondary side (when the tap of the first secondary side is electrically connected to the first end of the driving capacitor) or the entirety of the first secondary side (when the second end of the first secondary side is electrically connected to the first end of the driving capacitor) is connected to both ends of the driving capacitor. Therefore, N1 is the number of turns of the second primary coil, and N2 is the number of turns of the second secondary coil connected to both ends of the driving capacitor. The control circuit 150 adjusts the number of turns of the second secondary coil connected to both ends of the driving capacitor by controlling the conduction of the controllable switch electrically connected to the tap, and ultimately adjusts the equivalent capacitance in the adjustable capacitor circuit 140.

[0110] See also Figure 10In one possible implementation, the second transformer includes: a second primary side and at least two second secondary sides, the second primary side and the at least two second secondary sides share a magnetic core, the first end of the second primary side is electrically connected to the first transformer 120, the second end of the second primary side is grounded, the first end of each second secondary side is grounded, the second end of each second secondary side is electrically connected to the first end of the driving capacitor through a one-to-one corresponding controllable switch, and the second end of the driving capacitor is grounded.

[0111] In a possible implementation, at least two of the at least two second secondary sides have different numbers of coil turns. For example, any two of the at least two second secondary sides have different numbers of coil turns.

[0112] In this implementation, the second primary is fully connected to the resonant circuit, and the second secondary is also fully connected to both ends of the drive capacitor. Therefore, N1 is the number of turns on the second primary coil, and N2 is the number of turns on the second secondary coil electrically connected to the drive capacitor. The advantage of having independent second secondary coils is that they increase the independence of each secondary coil, reducing the impact of damage to one secondary coil on the remaining secondary coils.

[0113] See also Figure 11 In one possible implementation, the second transformer includes: a third primary side and a third secondary side, the third primary side and the third secondary side share a magnetic core, at least one tap is provided on the third primary side, a first end of the third primary side is grounded, a second end of the third primary side is electrically connected to the first transformer 120 via a corresponding controllable switch, each tap of the third primary side is electrically connected to the first transformer 120 via a one-to-one corresponding controllable switch, a first end of the third secondary side is grounded, a second end of the third secondary side is electrically connected to the first end of the driving capacitor, and the second end of the driving capacitor is grounded.

[0114] In this implementation, part of the third primary (when the tap of the third primary is electrically connected to the first transformer 120) or the entire third primary (when the second end of the third primary is electrically connected to the first transformer 120) is connected to the resonant circuit, and the entire third secondary is connected to both ends of the drive capacitor. Therefore, N1 is the number of turns of the third primary connected to the resonant circuit, and N2 is the number of turns of the third secondary.

[0115] See also Figure 12 In one possible implementation, the second transformer includes: a fourth secondary side and at least two fourth primary sides, the first end of each fourth primary side is grounded, the second end of each fourth primary side is electrically connected to the first transformer 120 through a one-to-one corresponding controllable switch, the first end of the fourth secondary side is grounded, the second end of the fourth secondary side is electrically connected to the first end of the driving capacitor, and the second end of the driving capacitor is grounded.

[0116] In a possible implementation, at least two of the at least two fourth primary sides have different numbers of coil turns. For example, any two of the at least two fourth primary sides have different numbers of coil turns.

[0117] The fourth primary is fully connected to the resonant circuit, and the fourth secondary is fully connected to both ends of the drive capacitor C0. Therefore, N1 is the number of turns of the fourth primary connected to the resonant circuit, and N2 is the number of turns of the fourth secondary. The control circuit 150 adjusts the output voltage of the fourth secondary by selecting the fourth primary electrically connected to the first transformer 120, thereby changing the equivalent circuit value of the adjustable capacitor circuit 140.

[0118] See also Figure 13 The present application also provides a power supply circuit 200 , which includes the resonant drive circuit 100 and the power conversion circuit provided in any of the aforementioned embodiments, and the power conversion circuit is driven by the resonant drive circuit 100 .

[0119] The power conversion circuit includes a plurality of switching transistors driven by the resonant driving circuit 100. The power conversion circuit can be at least one of a DC-DC conversion circuit, an AC-DC conversion circuit, and a DC-AC conversion circuit.

[0120] The power supply circuit provided by the present application has a resonant drive circuit 100 that can optimize itself so that the resonant drive circuit 100 operates in the optimal state, and the switching granularity during the optimization process is small and the no-load consistency is good. Therefore, the power supply circuit has good stability and low power consumption.

[0121] The present application provides a power supply, which includes the power supply circuit provided in the aforementioned embodiment.

[0122] With the power supply provided in the present application, the resonant drive circuit 100 inside the power supply has a good tolerance compensation function, so that the resonant drive circuit 100 works in an optimal state, thereby achieving the purpose of saving power consumption.

[0123] The present application provides a device including the power supply circuit of the aforementioned embodiment, or including the power supply of the aforementioned embodiment. The device can be various electronic devices with a built-in power supply circuit or power supply, such as a mobile phone, smart wearable product, computer, PDA, etc.

[0124] The device provided in this application can ensure that the driving circuit of the electronic device operates in the optimal state, thereby reducing power consumption, and at the same time ensure that the circuit driven by the driving circuit (such as the power supply circuit) can have good stability.

Claims

1. A resonant drive circuit, characterized in that: include: a switching circuit, the switching circuit being configured to be electrically connected to a power source; a first transformer, the first transformer being electrically connected to the switching circuit; a detection circuit, the detection circuit being electrically connected to the switch circuit, and the detection circuit being used to detect an operating state of the resonant drive circuit; an adjustable capacitor circuit, electrically connected to the switch circuit and the first transformer, respectively, the adjustable capacitor circuit comprising a driving capacitor and an adjustment module, the driving capacitor being electrically connected to the adjustment module, the adjustment module being configured to adjust an equivalent capacitance value of the adjustable capacitor circuit based on an output electrical signal of the adjustment module; the output electrical signal of the adjustment module comprising a current signal or a voltage signal; A control circuit is electrically connected to the detection circuit and the adjustable module respectively, and the control circuit is used to adjust the output electrical signal of the adjustment module based on the detection result of the detection circuit.

2. The resonant drive circuit according to claim 1, wherein: The resonant drive circuit includes at least two adjustable capacitance circuits, the at least two adjustable capacitance circuits include a first adjustable capacitance circuit and a second adjustable capacitance circuit, the first transformer includes a primary winding and a secondary winding, the first end of the primary winding is electrically connected to the first adjustable capacitance circuit, and the second end of the primary winding is electrically connected to the second adjustable capacitance circuit.

3. The resonant driving circuit according to claim 1, wherein: The regulation module includes: a first transistor and at least one second transistor, the control end of the first transistor is electrically connected to the control end of the second transistor, the first end of the driving capacitor is electrically connected to the first end of the second transistor, the second end of the driving capacitor is electrically connected to the control end of the first transistor and the control end of the second transistor respectively, the first end of the second transistor is electrically connected to the first transformer, and the first end of the first transistor is used to receive a reference current.

4. The resonant driving circuit according to claim 3, wherein: The regulating module further includes: at least one third transistor, the first end of the second transistor is electrically connected to the first transformer through the third transistor, and the control end of the third transistor is electrically connected to the control circuit.

5. The resonant driving circuit according to claim 4, characterized in that: The regulating module further includes: at least two second transistors and at least two third transistors; the first end of the driving capacitor is electrically connected to the first end of each second transistor, and the second end of the driving capacitor is electrically connected to the control end of each second transistor; Under the control of the control circuit, at a certain moment, at least one of the at least two third transistors is in a conducting state.

6. The resonant driving circuit according to claim 1, wherein: The regulation module includes: a first resistor, a second resistor, an operational amplifier, and a resistor switch array; wherein the first end of the first resistor is electrically connected to the first end of the driving capacitor and the first transformer respectively, the second end of the first resistor is electrically connected to the first end of the operational amplifier, the first end of the second resistor is electrically connected to the second end of the operational amplifier, and the second end of the second resistor is grounded; the resistor switch array includes at least one resistor switch branch, the first end of each resistor switch branch is electrically connected to the output end of the operational amplifier, and the second end of each resistor switch branch is electrically connected to the first end of the operational amplifier; the output end of the operational amplifier is electrically connected to the second end of the driving capacitor; the resistor switch branch includes a controllable switch and a feedback resistor connected in series, and the control end of the controllable switch is electrically connected to the control circuit.

7. The resonant driving circuit according to claim 6, wherein: The resistance switch array includes at least two resistance switch branches; Under the control of the control circuit, at a certain moment, at least one of the at least two resistance switch branches is in a conducting state.

8. The resonant driving circuit according to claim 1, wherein: The regulation module includes: a first voltage-dividing resistor, a voltage-dividing resistor switch array, a compensation resistor and an operational amplifier, wherein the first end of the first voltage-dividing resistor is electrically connected to the first end of the operational amplifier, and the second end of the first voltage-dividing resistor is grounded. The voltage-dividing resistor switch array includes at least one voltage-dividing resistor switch branch, the first end of each voltage-dividing resistor switch branch is electrically connected to the first end of the first voltage-dividing resistor, and the second end of each voltage-dividing resistor switch branch is electrically connected to the first end of the driving capacitor and the first transformer, respectively. Each voltage-dividing resistor switch branch includes a controllable switch and a voltage-dividing resistor connected in series; the second end of the driving capacitor is electrically connected to the output end of the operational amplifier, the first end of the operational amplifier is electrically connected to the output end of the operational amplifier, the second end of the operational amplifier is grounded to the first end of the compensation resistor, and the second end of the compensation resistor is grounded.

9. The resonant driving circuit according to claim 8, characterized in that: The voltage-dividing resistor switch array includes at least two voltage-dividing resistor switch branches; Under the control of the control circuit, at a certain moment, at least one voltage-dividing resistance switch branch among the at least two resistance switch branches is in a conducting state.

10. The resonant driving circuit according to claim 1, wherein: The regulating module further includes: a second transformer; a primary side of the second transformer is electrically connected to the first transformer, and a secondary side of the second transformer is electrically connected to the driving capacitor.

11. The resonant driving circuit according to claim 10, wherein: The second transformer includes: a first primary side and a first secondary side, the first primary side and the first secondary side share a magnetic core, the first end of the first primary side is electrically connected to the first transformer, the second end of the first primary side is grounded, and at least one tap is provided on the first secondary side, the first end of the first secondary side is grounded, the second end of the first secondary side is electrically connected to the first end of the driving capacitor through a corresponding controllable switch, each tap of the first secondary side is electrically connected to the first end of the driving capacitor through a one-to-one corresponding controllable switch, and the second end of the driving capacitor is grounded.

12. The resonant driving circuit according to claim 10, wherein: The second transformer includes: a second primary side and at least two second secondary sides, the second primary side and the at least two second secondary sides share a magnetic core, the first end of the second primary side is electrically connected to the first transformer, the second end of the second primary side is grounded, the first end of each second secondary side is grounded, the second end of each second secondary side is electrically connected to the first end of the driving capacitor through a one-to-one corresponding controllable switch, and the second end of the driving capacitor is grounded.

13. The resonant driving circuit according to claim 10, wherein: The second transformer includes: a third primary side and a third secondary side, the third primary side and the third secondary side share a magnetic core, the third primary side is provided with at least one tap, the first end of the third primary side is grounded, the second end of the third primary side is electrically connected to the first transformer through a corresponding controllable switch, each tap of the third primary side is electrically connected to the first transformer through a one-to-one corresponding controllable switch, the first end of the third secondary side is grounded, the second end of the third secondary side is electrically connected to the first end of the driving capacitor, and the second end of the driving capacitor is grounded.

14. The resonant driving circuit according to claim 10, wherein: The second transformer includes: a fourth secondary side and at least two fourth primary sides, the first end of each of the fourth primary sides is grounded, the second end of each of the fourth primary sides is electrically connected to the first transformer through a one-to-one corresponding controllable switch, the first end of the fourth secondary side is grounded, the second end of the fourth secondary side is electrically connected to the first end of the driving capacitor, and the second end of the driving capacitor is grounded.

15. A power supply circuit, characterized in that: The power supply circuit includes the resonant drive circuit and the power conversion circuit according to any one of claims 1 to 14, and the power conversion circuit is driven by the resonant drive circuit.

16. A power supply, characterized in that: The power supply includes the power supply circuit according to claim 15 .

17. A device, characterized in that The device comprises the power supply circuit according to claim 15, or the device comprises the power supply according to claim 16.

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