Switching charging circuit, terminal and control method of switching charging circuit

Abstract

The present disclosure relates to a switching charging circuit, a terminal and a control method of the switching charging circuit, and belongs to the technical field of circuits. The switching circuit has multiple charging modes. When the input voltage and the output voltage of the switching circuit satisfy a preset relationship detected by a voltage detection unit, the switching circuit can be switched to the corresponding charging mode to charge the battery of the terminal, thereby adapting to the needs in multiple scenarios and improving the charging efficiency through switching of the charging mode, and thus improving the user experience.

Description

Technical Field

[0001] This disclosure relates to the field of circuit technology, and in particular to a switching charging circuit and terminal, and a control method for the switching charging circuit. Background Technology

[0002] With the development of charging technology, fast charging technology has become widespread. The inventors, through research on existing fast charging technologies, discovered the following problems: traditional charging circuits can only provide one charging mode, thus failing to adapt to various charging scenarios, and they cannot improve charging efficiency by switching charging modes, thus reducing the user experience. Summary of the Invention

[0003] To solve the above-mentioned technical problems, or at least partially solve them, this disclosure provides a switching charging circuit and terminal, and a control method for the switching charging circuit.

[0004] In a first aspect, this disclosure provides a switching charging circuit, including a voltage detection unit, a control circuit, and a switching circuit; wherein...

[0005] The voltage detection unit is used to detect whether the input voltage and output voltage of the switching circuit meet the preset relationship, and generates a corresponding switching signal when the preset relationship is met;

[0006] The control circuit is used to generate periodic control signals;

[0007] The switching circuit is used to switch to the corresponding charging mode based on the switching signal and the periodic control signal in order to charge the terminal's battery.

[0008] In some embodiments, the switching circuit includes:

[0009] The first switch, the second switch, the third switch, and the fourth switch are connected in series; wherein the drain of the first switch is connected to the voltage input terminal.

[0010] The first capacitor is connected in parallel with the second and third switching transistors;

[0011] The first inductor has its first end connected to the node between the second and third switching transistors.

[0012] The second capacitor has its first terminal connected to the second terminal of the first inductor, and its second terminal grounded; the node between the first inductor and the second capacitor is connected to the voltage output terminal.

[0013] In some embodiments, the switching charging circuit further includes:

[0014] The buck converter circuit has its input terminal electrically connected to the output terminal of the switching circuit, and its output terminal electrically connected to the battery. It is used to step down the output voltage of the switching circuit.

[0015] The shunt regulating circuit has its input terminal electrically connected to the output terminal of the switching circuit, and its output terminal electrically connected to the battery. It is used to shunt the output current of the switching circuit.

[0016] In some embodiments, the switching charging circuit further includes:

[0017] A load switch circuit, located between the buck converter circuit and the battery, is used to disconnect the switching charging circuit when the output voltage of the buck converter circuit exceeds a preset voltage.

[0018] When the output current of the buck converter circuit exceeds the preset current, the switching charging circuit is disconnected.

[0019] In some embodiments, the buck converter circuit may be the same as or different from the shunt regulator circuit.

[0020] Secondly, this disclosure provides a terminal including the switching charging circuit of the first aspect of this disclosure.

[0021] Thirdly, this disclosure provides a control method for a switching charging circuit, including:

[0022] Detect the input and output voltage values ​​of the switching circuit;

[0023] If the ratio of the input voltage value to the output voltage value meets the preset ratio, the switching charging circuit is controlled to switch to the first charging mode.

[0024] If the ratio of the input voltage value to the output voltage value does not meet the preset ratio, the switching charging circuit will be controlled to switch to the second charging mode.

[0025] In some embodiments, controlling the switching charging circuit to switch to a first charging mode includes:

[0026] During the first charging cycle, the first and third switching transistors in the switching circuit of the control switching charging circuit are turned on, and the second and fourth switching transistors are turned off, so that the first capacitor is charged.

[0027] During the second charging cycle, the first and third switching transistors are turned off, while the second and fourth switching transistors are turned on, causing the first capacitor to discharge.

[0028] In some embodiments, if the ratio of the input voltage value to the output voltage value is greater than a preset ratio, controlling the switching charging circuit to switch to the second charging mode includes:

[0029] During the first charging cycle, the first and third switching transistors in the control switching circuit are turned on, and the second and fourth switching transistors are turned off, so that the first capacitor is charged.

[0030] During the second charging cycle, the first switch is controlled to be turned off, and the fourth switch is controlled to be turned on.

[0031] During the third charging cycle, the second switch is turned on and the third switch is turned off to discharge the first capacitor.

[0032] During the fourth charging cycle, the second switch is turned off and the third switch is turned on.

[0033] In some embodiments, if the ratio of the input voltage value to the output voltage value is less than a preset ratio, controlling the switching charging circuit to switch to the second charging mode includes:

[0034] During the first charging cycle, the first and second switching transistors in the control switching circuit are turned on, while the third and fourth switching transistors are turned off.

[0035] During the second charging cycle, the second switch is controlled to be turned off and the fourth switch is controlled to be turned on, so that the first capacitor is charged.

[0036] During the third charging cycle, the second switch is turned on and the fourth switch is turned off.

[0037] During the fourth charging cycle, the first switch is turned off and the fourth switch is turned on, causing the first capacitor to discharge.

[0038] The technical solution provided in this disclosure has the following advantages compared with the prior art:

[0039] The switching circuit has multiple charging modes. When the voltage detection unit detects that the input voltage and output voltage of the switching circuit meet the preset relationship, the switching circuit can switch to the corresponding charging mode to charge the terminal's battery. This can adapt to the needs of various scenarios, and the switching charging mode can improve charging efficiency, thereby improving the user experience. Attached Figure Description

[0040] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure.

[0041] To more clearly illustrate the technical solutions in the embodiments of this disclosure or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, those skilled in the art can obtain other drawings based on these drawings without creative effort.

[0042] Figure 1 A structural block diagram of a switching charging circuit provided in an embodiment of this disclosure;

[0043] Figure 2 A structural diagram of the switching circuit provided in the embodiments of this disclosure;

[0044] Figure 3 A structural block diagram of another switching charging circuit provided in this disclosure embodiment;

[0045] Figure 4 This is a schematic flowchart of a control method for a switching charging circuit provided in an embodiment of the present disclosure;

[0046] Figure 5 A schematic diagram of the operation of the switching charging circuit provided in the embodiments of this disclosure in the first charging mode;

[0047] Figure 6 A line graph showing the changes in voltage at each node and current in the first inductor when the switching circuit provided in the embodiment of this disclosure is in the first charging mode;

[0048] Figure 7 A schematic diagram of the workflow of the switching charging circuit provided in the embodiments of this disclosure when it is in the first working state of the second charging mode;

[0049] Figure 8 Line graph showing the changes in voltage at each node and current in the first inductor when the switching circuit provided in the embodiment of this disclosure is in the first operating state of the second charging mode;

[0050] Figure 9 A line graph showing the changes in output voltage and current of the first inductor when the switching circuit provided in this embodiment is in a stable state;

[0051] Figure 10 A schematic diagram of the workflow of the switching charging circuit provided in the embodiments of this disclosure when it is in the second working state of the second charging mode;

[0052] Figure 11 Line graph showing the changes in voltage at each node and current in the first inductor when the switching circuit provided in the embodiment of this disclosure is in the second operating state of the second charging mode. Detailed Implementation

[0053] To better understand the above-mentioned objectives, features, and advantages of this disclosure, the solutions disclosed herein will be further described below. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other.

[0054] Numerous specific details are set forth in the following description in order to provide a full understanding of this disclosure, but this disclosure may also be implemented in other ways different from those described herein; obviously, the embodiments in the specification are only some, and not all, of the embodiments of this disclosure.

[0055] Traditional charging circuits can only provide one charging mode, which is not suitable for various charging scenarios and cannot improve charging efficiency by switching charging modes, thus reducing the user experience. The technical solution disclosed in this paper provides a switching circuit with multiple charging modes. When the voltage detection unit detects that the input voltage and output voltage of the switching circuit meet a preset relationship, the switching circuit can switch to the corresponding charging mode to charge the terminal's battery. This can adapt to the needs of various scenarios, and the switching of charging modes can improve charging efficiency, thereby improving the user experience.

[0056] Specifically, firstly, Figure 1 This is a structural block diagram of a switching charging circuit 1 provided in an embodiment of the present disclosure, as shown below. Figure 1 As shown, it includes a voltage detection unit 100, a control circuit 200, and a switching circuit 300; wherein,

[0057] The voltage detection unit 100 is used to detect whether the input voltage and output voltage of the switching circuit 300 meet the preset relationship, and generates a corresponding switching signal when the preset relationship is met;

[0058] The control circuit 200 is used to generate periodic control signals;

[0059] The switching circuit 300 is used to switch to the corresponding charging mode based on the switching signal and the periodic control signal in order to charge the battery of the terminal.

[0060] In this embodiment, the control circuit can be a PWM control circuit, which controls the switching circuit to operate by generating a periodic PWM control signal. The switching circuit has multiple charging modes, and the condition for switching charging modes depends on whether the input voltage and output voltage meet a preset relationship. For example, the preset relationship is that the input voltage is twice the output voltage. When the input voltage is twice the output voltage, the switching circuit switches to the first charging mode; when the input voltage is greater than twice the output voltage or less than twice the output voltage, the switching circuit switches to the second charging mode.

[0061] The switching circuit in this embodiment has multiple charging modes. When the voltage detection unit detects that the input voltage and output voltage of the switching circuit meet a preset relationship, the switching circuit can switch to the corresponding charging mode to charge the terminal's battery. This can adapt to the needs of various scenarios, and the charging efficiency can be improved by switching charging modes, thereby improving the user experience.

[0062] In some embodiments, Figure 2 A structural diagram of the switching circuit provided in the embodiments of this disclosure is shown below. Figure 2 As shown, the switching circuit 300 includes:

[0063] The first switch Q1, the second switch Q2, the third switch Q3, and the fourth switch Q4 are connected in series; wherein the drain of the first switch Q1 is connected to the voltage input terminal.

[0064] The first capacitor C1 is connected in parallel with the second switch Q2 and the third switch Q3;

[0065] The first inductor L1 and the first end of the first inductor C1 are connected to the node between the second switch Q2 and the third switch Q3;

[0066] The second capacitor C2 has its first end connected to the second end of the first inductor L1, and its second end grounded; the node between the first inductor L1 and the second capacitor C2 is connected to the voltage output terminal.

[0067] In the embodiments of this disclosure, the existing BUCK circuit has low charging efficiency due to the conduction and cutoff losses of the switching transistor and the coil and core losses of the inductor. Furthermore, the energy lost by the BUCK circuit is converted into heat energy, causing the terminal to overheat severely when using the existing Buck circuit charging scheme, thus making it impossible to charge with a large charging current.

[0068] The switching circuit provided in this embodiment improves upon the existing BUCK circuit by adding a second and a third switching transistor, and connecting a first capacitor in parallel across the second and third switching transistors, thereby enabling the switching circuit to have three operating states.

[0069] Specifically, the buck converter circuit provided in this disclosure has an output voltage V under three operating states. OUT At 0, V IN / 2, and V IN Alternating between these states, when the input voltage is higher than twice the output voltage, the voltages of switching nodes G1, G2, and G3 in the switching circuit will alternate between 0 and V. IN Alternating between / 2; when the input voltage is less than twice the output voltage, the voltages of switching nodes G1, G2, and G3 will alternate between V and 2.IN and V IN The switching circuit alternates between / 2, so even when the input voltage is high, the switching circuit provided in this embodiment can provide a stable output voltage by switching between the three operating states.

[0070] Since the switching circuit in this embodiment can accept a higher input voltage, such as 20V, 30V or higher, the input current decreases accordingly as the input voltage increases when the input power is constant. Therefore, the PD protocol specification is not required, the charging cable does not need to add an Emark chip, and the power adapter does not need to add a chip that supports the PD protocol. It can be used for both wired high-power charging and wireless high-power charging, while also effectively saving production costs.

[0071] In some embodiments, such as Figure 3 As shown, the switching charging circuit 1 also includes:

[0072] A step-down converter circuit 400 is provided, with its input terminal electrically connected to the output terminal of the switching circuit 300 and its output terminal electrically connected to the battery. It is used to step down the output voltage of the switching circuit 300.

[0073] The shunt regulating circuit 500 has its input terminal electrically connected to the output terminal of the switching circuit 300, and its output terminal electrically connected to the battery. It is used to shunt the output current of the switching circuit 300.

[0074] In this embodiment of the disclosure, the buck converter circuit can use a charge pump in the prior art to step down the output voltage of the switching circuit to reach the charging voltage of the terminal battery, so as to perform high-power fast charging of the terminal battery.

[0075] The shunt regulating circuit can shunt the output current of the switching circuit, thereby reducing the charging current and protecting the switching charging circuit for safe operation. Furthermore, the shunt regulating circuit can also perform trickle charging, pre-charging, constant current, and constant voltage functions. The shunt regulating circuit can employ existing BUCK circuits or charge pumps, or other circuits; this disclosure does not impose specific limitations on the embodiments.

[0076] In some embodiments, such as Figure 3 As shown, the switching charging circuit 1 also includes:

[0077] A load switch circuit 600, located between the buck converter circuit 400 and the battery, is used to disconnect the switching charging circuit when the output voltage of the buck converter circuit 400 exceeds a preset voltage.

[0078] When the output current of the buck converter circuit 400 exceeds the preset current, the switching charging circuit is disconnected.

[0079] In this embodiment of the disclosure, a load switch circuit can also be provided to provide overcurrent and overvoltage protection for the switching charging circuit.

[0080] It should be noted that, according to actual needs, the switching charging circuit provided in this disclosure embodiment can also connect multiple step-down converter circuits and load switching circuits in parallel between the switching circuit and the terminal battery. This disclosure embodiment does not impose specific limitations.

[0081] In some embodiments, the buck converter circuit 400 may be the same as or different from the shunt regulator circuit 500.

[0082] In the embodiments of this disclosure, the buck converter circuit and the shunt regulation circuit may use the same circuit, such as the existing BUCK circuit, or other circuits, or different circuits. This disclosure does not impose any specific limitations.

[0083] Secondly, embodiments of this disclosure provide a terminal including the switching charging circuit of the first aspect of this disclosure.

[0084] In the embodiments of this disclosure, the terminal includes, but is not limited to, power-consuming devices such as smartphones, tablets, laptops, PDAs, and wearable smart devices. The switching charging circuit in the embodiments of this disclosure can be widely used in various terminals.

[0085] It should be noted that the switching charging circuit provided in this embodiment can also be applied to power adapters.

[0086] Thirdly, Figure 4 This is a schematic flowchart of a control method for a switching charging circuit provided in an embodiment of the present disclosure, as shown below. Figure 4 As shown, it includes:

[0087] S401. Detect the input and output voltage values ​​of the switching circuit;

[0088] In this step, the input voltage value V of the switching circuit is first detected. IN and output voltage value V OUT Then, by comparing the two values, the switching circuit is brought into the corresponding working state.

[0089] S402. If the ratio of the input voltage value to the output voltage value meets the preset ratio, then control the switching charging circuit to switch to the first charging mode.

[0090] In this step, the preset ratio is, for example, twice the input voltage value and twice the output voltage value. When the input voltage value is detected to be twice the output voltage value, the switching charging circuit is controlled to switch to the first charging mode.

[0091] S403. If the ratio of the input voltage value to the output voltage value does not meet the preset ratio, the switching charging circuit is controlled to switch to the second charging mode.

[0092] In this step, when the input voltage value is detected to be greater than twice the output voltage value or less than twice the output voltage value, the switching charging circuit is controlled to switch to the second charging mode.

[0093] The switching circuit in this embodiment has multiple charging modes. When the input voltage and output voltage of the switching circuit meet or do not meet the preset ratio, the switching circuit can switch to the corresponding charging mode to charge the terminal's battery. This can adapt to the needs of various scenarios, and the charging efficiency can be improved by switching the charging mode, thereby improving the user experience.

[0094] In some embodiments, Figure 4 Based on the method shown, such as Figure 5 As shown in S402, controlling the switching charging circuit to switch to the first charging mode includes:

[0095] S501. During the first charging cycle, the first and third switching transistors in the switching circuit of the switching charging circuit are turned on, and the second and fourth switching transistors are turned off, so that the first capacitor is charged.

[0096] In this step, when the input voltage value V IN It is the output voltage value V OUT When it is twice the size, such as Figure 6 As shown, during the first charging cycle T1, the first switch Q1 and the third switch Q3 in the control switching circuit are turned on, while the second switch Q2 and the fourth switch Q4 are turned off. At this time, the voltage at node G1 is... Voltage of node G3 Voltage of node G2 At this time, the first capacitor C1 begins to charge, and the first inductor L1 is energized.

[0097] S502. During the second charging cycle, control the first and third switching transistors to turn off, and control the second and fourth switching transistors to turn on, so that the first capacitor discharges.

[0098] In this step, during the second charging cycle T2, the first switch Q1 and the third switch Q3 are turned off, while the second switch Q2 and the fourth switch Q4 are turned on. At this time, the voltage at node G1 is... Voltage of node G2 Voltage of node G3 The first capacitor C1 is discharged, while the first inductor L1 continues to be energized.

[0099] In some embodiments, Figure 4 Based on the method shown, such as Figure 7 As shown, if the ratio of the input voltage value to the output voltage value is greater than a preset ratio, then in S403, controlling the switching charging circuit to switch to the second charging mode includes:

[0100] S701. During the first charging cycle, the first and third switching transistors in the control switching circuit are turned on, and the second and fourth switching transistors are turned off, so that the first capacitor is charged.

[0101] In this step, the preset multiplier is, for example, twice, then when the input voltage value V... IN More than twice the output voltage value V OUT At times, such as Figure 8 As shown, during the first charging cycle T1, the first switch Q1 and the third switch Q3 in the control switching circuit are turned on, while the second switch Q2 and the fourth switch Q4 are turned off. At this time, the voltage at node G1 is... Voltage of node G3 Voltage of node G2 At this time, the first capacitor C1 begins to charge, and the first inductor L1 is energized.

[0102] S702: During the second charging cycle, control the first switch to be turned off and control the fourth switch to be turned on.

[0103] In this step, during the second charging cycle T2, the first switch Q1 is turned off, and the fourth switch Q4 is turned on. At this time, the voltage at node G1 is... Voltage of node G2 Voltage of node G3 The first inductor L1 is de-energized.

[0104] S703. During the third charging cycle, control the second switch to turn on and control the third switch to turn off, so that the first capacitor discharges.

[0105] In this step, during the third charging cycle T3, the second switch Q2 is turned on and the third switch Q3 is turned off. At this time, the voltage at node G1 is... Voltage of node G2 Voltage of node G3 The first capacitor C1 begins to discharge, and the first inductor L1 resumes energization.

[0106] S704. During the fourth charging cycle, control the second switch to turn off and control the third switch to turn on.

[0107] In this step, during the fourth charging cycle T4, the second switch Q2 is turned off, and the third switch Q3 is turned on. At this time, the voltage at node G1 is... Voltage of node G2 Voltage of node G3 The first inductor L1 is de-energized.

[0108] In addition, such as Figure 9 As shown, with the input voltage V IN The decrease in voltage leads to a corresponding increase in the duration of the first charging cycle T1 and the third charging cycle T3, which in turn increases the duty cycle of these two cycles, ultimately resulting in a stable output voltage V. OUT That is, the voltage of node G2

[0109] In some embodiments, Figure 4 Based on the method shown, such as Figure 10 As shown, if the ratio of the input voltage value to the output voltage value is less than a preset ratio, then in S403, controlling the switching charging circuit to switch to the second charging mode includes:

[0110] S1001. During the first charging cycle, the first and second switching transistors in the control switching circuit are turned on, and the third and fourth switching transistors are turned off.

[0111] In this step, with Figure 7 The method shown differs from the one described above, except that when the input voltage value V is detected... IN Less than twice the output voltage value V OUT At times, such as Figure 11 As shown, during the first charging cycle T1, the first switch Q1 and the second switch Q2 are turned on, while the third switch Q3 and the fourth switch Q4 are turned off. At this time, the voltage at node G1 is... Voltage of node G2 Voltage of node G3 The first inductor L1 is energized.

[0112] S1002. During the second charging cycle, control the second switch to be turned off and control the fourth switch to be turned on to charge the first capacitor.

[0113] In this step, during the second charging cycle T2, the second switch Q2 is turned off, and the fourth switch Q4 is turned on. At this time, the voltage at node G1 is... Voltage of node G2 Voltage of node G3 The first capacitor C1 is charging, while the first inductor L1 continues to be energized.

[0114] S1003. During the third charging cycle, control the second switch to turn on and control the fourth switch to turn off.

[0115] In this step, during the third charging cycle T3, the second switch Q2 is turned on, and the fourth switch Q4 is turned off. At this time, the voltage at node G1 is... Voltage of node G2 Voltage of node G3 The first inductor L1 continues to be energized.

[0116] S1004. During the fourth charging cycle, control the first switch to turn off and control the fourth switch to turn on, so that the first capacitor discharges.

[0117] In this step, during the fourth charging cycle T4, the first switch Q1 is turned off, and the fourth switch Q4 is turned on. At this time, the voltage at node G1 is... Voltage of node G2 Voltage of node G3 The first capacitor C1 begins to discharge, while the first inductor L1 continues to be energized.

[0118] Furthermore, with the input voltage V IN The voltage at node G2 continuously decreases. By adjusting the duration of each charging cycle, the first switch Q1 and the second switch Q2 are both in the on state within the same charging cycle, thereby causing the voltage at node G2 to remain at V. IN and V IN Alternating between / 2 and 2.

[0119] The control method for the switching circuit provided in the above-described embodiments of this disclosure, combined with the switching charging circuit provided in the first aspect of this disclosure, reduces the voltage across the inductor and the switching transistor in all operating states of the switching charging circuit, thereby doubling the switching frequency at the switching node and reducing the maximum current ripple of the inductor to one-quarter of that of a conventional buck converter. Due to the reduction in current ripple, smaller and thinner inductors can be used, reducing coil resistance and power loss. Furthermore, by reducing the voltage across the inductor and the switching transistor in all operating states of the switching charging circuit, the losses of the switching transistor are reduced, thus reducing the heat generation of the switching charging circuit.

[0120] In some embodiments, the duration of the first charging cycle and the second charging cycle in the first charging mode, and the duration of the first charging cycle, the second charging cycle, the third charging cycle and the fourth charging cycle in the second charging mode are controlled by the control circuit.

[0121] In this embodiment of the disclosure, a PWM control circuit can be used to control the duration of each charging cycle of the switching circuit.

[0122] In some embodiments, the control method for the switching charging circuit further includes:

[0123] Based on the preset relationship between the input voltage value and the duration of the charging cycle, the durations of the first and second charging cycles in the first charging mode, as well as the durations of the first, second, third, and fourth charging cycles in the second charging mode, are adjusted.

[0124] In this embodiment of the disclosure, the duration of each charging cycle of the switching circuit can be adjusted according to the input voltage value. For example, the duration of the corresponding charging cycle can be set according to the preset ratio between the input voltage value and the charging cycle duration. This embodiment of the disclosure does not impose any specific limitations.

[0125] The above description is merely a preferred embodiment of this disclosure and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of this disclosure is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the above-described concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features disclosed in this disclosure that have similar functions.

Claims

1. A switching charging circuit, characterized in that, It includes a voltage detection unit, a control circuit, and a switching circuit; among which, The voltage detection unit is used to detect whether the input voltage and output voltage of the switching circuit meet a preset relationship, and generate a corresponding switching signal when the preset relationship is met; The control circuit is used to generate periodic control signals; The switching circuit is used to switch to the corresponding charging mode based on the switching signal and the periodic control signal in order to charge the terminal's battery. The switching circuit includes: A first switch, a second switch, a third switch, and a fourth switch are connected in series; wherein the drain of the first switch is connected to the voltage input terminal. The first capacitor is connected in parallel with the second and third switching transistors; A first inductor, the first end of which is connected to the node between the second switch and the third switch; The second capacitor has its first terminal connected to the second terminal of the first inductor, and its second terminal grounded; wherein the node between the first inductor and the second capacitor is connected to the voltage output terminal. When the ratio of the input voltage value to the output voltage value meets a preset ratio, the switching charging circuit switches to the first charging mode. During the first charging cycle, the first and third switching transistors are turned on, and the second and fourth switching transistors are turned off, so as to charge the first capacitor. During the second charging cycle, the first and third switching transistors are turned off, and the second and fourth switching transistors are turned on, so as to discharge the first capacitor. When the ratio of the input voltage value to the output voltage value is greater than the preset ratio, the switching charging circuit switches to the second charging mode. During the first charging cycle, the first and third switches in the switching circuit of the switching charging circuit are turned on, while the second and fourth switches are turned off, allowing the first capacitor to charge. During the second charging cycle, the first switch is turned off, and the fourth switch is turned on. During the third charging cycle, the second switch is turned on, and the third switch is turned off, allowing the first capacitor to discharge. During the fourth charging cycle, the second switch is turned off, and the third switch is turned on; or... When the ratio of the input voltage value to the output voltage value is less than the preset ratio, the switching charging circuit switches to the second charging mode. In the first charging cycle, the first and second switching transistors in the switching circuit are turned on, and the third and fourth switching transistors are turned off. In the second charging cycle, the second switching transistor is turned off, and the fourth switching transistor is turned on, so that the first capacitor is charged. In the third charging cycle, the second switching transistor is turned on, and the fourth switching transistor is turned off. In the fourth charging cycle, the first switching transistor is turned off, and the fourth switching transistor is turned on, so that the first capacitor is discharged.

2. The switching charging circuit as described in claim 1, characterized in that, Also includes: A buck converter circuit, wherein the input terminal of the buck converter circuit is electrically connected to the output terminal of the switching circuit, and the output terminal of the buck converter circuit is electrically connected to the battery, for reducing the output voltage of the switching circuit; The current shunt regulating circuit has its input terminal electrically connected to the output terminal of the switching circuit, and its output terminal electrically connected to the battery, for shunting the output current of the switching circuit.

3. The switching charging circuit as described in claim 2, characterized in that, Also includes: A load switching circuit, located between the buck converter circuit and the battery, is used to disconnect the switching charging circuit when the output voltage of the buck converter circuit exceeds a preset voltage. When the output current of the buck converter circuit exceeds the preset current, the switching charging circuit is disconnected.

4. The switching charging circuit as described in claim 2, characterized in that, The step-down converter circuit may be the same as or different from the shunt regulating circuit.

5. A terminal, characterized in that, Includes the switching charging circuit as described in any one of claims 1-4.

6. A control method for a switching charging circuit, characterized in that, include: Detect the input and output voltage values ​​of the switching circuit; If the ratio of the input voltage value to the output voltage value meets a preset ratio, then the switching charging circuit is controlled to switch to the first charging mode; If the ratio of the input voltage value to the output voltage value does not meet the preset ratio, the switching charging circuit is controlled to switch to the second charging mode. Wherein, controlling the switching charging circuit to switch to the first charging mode includes: During the first charging cycle, the first and third switching transistors in the switching circuit of the switching charging circuit are turned on, and the second and fourth switching transistors are turned off, so that the first capacitor is charged. During the second charging cycle, the first and third switching transistors are controlled to be turned off, and the second and fourth switching transistors are controlled to be turned on, so that the first capacitor is discharged. If the ratio of the input voltage value to the output voltage value is greater than a preset ratio, then controlling the switching charging circuit to switch to the second charging mode includes: During the first charging cycle, the first and third switching transistors in the switching circuit are turned on, and the second and fourth switching transistors are turned off, so that the first capacitor is charged. During the second charging cycle, the first switch is controlled to be turned off, and the fourth switch is controlled to be turned on. During the third charging cycle, the second switch is turned on and the third switch is turned off to discharge the first capacitor. During the fourth charging cycle, the second switch is controlled to be turned off, and the third switch is controlled to be turned on. or, If the ratio of the input voltage value to the output voltage value is less than a preset ratio, then controlling the switching charging circuit to switch to the second charging mode includes: During the first charging cycle, the first and second switching transistors in the switching circuit are turned on, while the third and fourth switching transistors are turned off. During the second charging cycle, the second switch is controlled to be turned off, and the fourth switch is controlled to be turned on, so that the first capacitor is charged. During the third charging cycle, the second switch is turned on and the fourth switch is turned off. During the fourth charging cycle, the first switch is controlled to be turned off, and the fourth switch is controlled to be turned on, so that the first capacitor is discharged.

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