Charging circuit and electronic equipment

Abstract

The utility model relates to a charging circuit and electronic equipment, and the charging circuit is used for supplying power to a battery, and comprises an input end; the first branch circuit is connected between the input end and the battery; the second branch circuit is connected between the input end and the battery, the second branch circuit comprises a charging element, and the charging element changes current flowing into the charging element and outputs the current to the battery; when the first branch circuit is connected and the second branch circuit is disconnected, the input end is connected with the battery through the first branch circuit, and when the first branch circuit is disconnected and the second branch circuit is connected, the input end is connected with the battery through the second branch circuit. According to the charging circuit and the charging method, the charging circuit can select a direct charging path with lower specific impedance in the charging process under the condition of keeping lower setting cost of the charging circuit, so that the charging efficiency of the charging circuit in a low-current charging stage is improved.

Description

Technical Field

[0001] The present disclosure relates to the technical field of battery charging, and particularly to a charging circuit and an electronic device. Background Art

[0002] With the rapid development of mobile communication technology, electronic devices such as mobile phones and tablet computers have become indispensable devices in people's daily lives. To facilitate users' daily use and reduce the situation where electronic devices are in low battery, many electronic devices are configured with a fast charging function.

[0003] To improve the charging efficiency of electronic devices, the charge pump technology has become the mainstream fast charging solution for electronic devices. However, when the charging power of an electronic device decreases due to factors such as changes in the charging stage or heat generation, the charging efficiency will have a large loss. Summary of the Utility Model

[0004] To overcome the problems existing in the related art, the present disclosure provides a charging circuit and an electronic device.

[0005] According to the first aspect of the embodiments of the present disclosure, a charging circuit is provided. The charging circuit is used to supply power to a battery and includes: an input terminal; a first branch connected between the input terminal and the battery; a second branch connected between the input terminal and the battery. The second branch includes a charging element that changes the current flowing into the charging element and outputs it to the battery. When the first branch is conducting and the second branch is disconnected, the input terminal is connected to the battery through the first branch. When the first branch is disconnected and the second branch is conducting, the input terminal is connected to the battery through the second branch.

[0006] In some embodiments, the charging stage of the charging circuit includes a first charging stage and a second charging stage. When the charging circuit is in the first charging stage, the input terminal is connected to the battery through the first branch, and the current charged into the battery is less than or equal to a threshold current. When the charging circuit is in the second charging stage, the input terminal is connected to the battery through the second branch, and the current charged into the battery is greater than the threshold current, where the threshold current is less than or equal to the rated input current of the input terminal.

[0007] In some embodiments, the charging circuit includes a first switching element disposed on the first branch. When the charging circuit is in the first charging stage, the first switching element conducts the first branch to connect the input terminal to the battery through the first branch. When the charging circuit is in the second charging stage, the first switching element disconnects the first branch.

[0008] In some embodiments, the charging circuit includes a second switching element disposed in the second branch. When the charging circuit is in the second charging stage, the second switching element disconnects the second branch; when the charging circuit is in the first charging stage, the second switching element conducts the second branch to connect the input end to the battery through the second branch.

[0009] In some embodiments, the charging circuit includes an overvoltage protection element disposed between the input end and the battery. When the voltage input at the input end is greater than the threshold voltage, the overvoltage protection element disconnects to disconnect the connection between the input end and the battery.

[0010] In some embodiments, the first switching element and the overvoltage protection element are metal-oxide-semiconductor field effect transistors.

[0011] In some embodiments, the first switching element includes a first body diode, the overvoltage protection element includes a second body diode, and the anodes of the first body diode and the second body diode are disposed opposite to each other.

[0012] In some embodiments, the charging element is a charge pump; when the charging circuit is in the second charging stage, the charging element disconnects the second branch; when the charging circuit is in the first charging stage, the charging element conducts the second branch to connect the input end to the battery through the second branch.

[0013] In some embodiments, the charging circuit further includes a processing unit connected to the first switching element, and the processing unit controls the conduction state of the first switching element.

[0014] In some embodiments, the processing unit is connected to the charging element, and the processing unit controls the conduction and shutdown of the charging element; the charging element is connected to the first switching element, and the processing unit controls the conduction state of the first switching element through the charging element.

[0015] In some embodiments, the charging circuit further includes a power management integrated circuit, one end of which is electrically connected to the input end, and the other end of which is electrically connected to the battery.

[0016] According to a second aspect of the embodiments of the present disclosure, there is provided an electronic device, which includes the charging circuit according to any one of the first aspect.

[0017] In some embodiments, the electronic device includes: a main board provided with a first switching element; a charging chip disposed on the main board, the charging chip including the charging element and a power management integrated circuit.

[0018] The technical solutions provided by the embodiments of the present disclosure may include the following beneficial effects: By providing a first branch directly connecting the input end and the battery and a second branch provided with a charging element in the charging circuit, the present disclosure enables the charging circuit to select a direct charging path with a lower impedance during the charging process while maintaining a relatively low cost of the charging circuit setup, thereby improving the charging efficiency of the charging circuit in the low-current charging stage.

[0019] It should be understood that the above general description and the following detailed description are merely exemplary and explanatory, and cannot limit the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings herein are incorporated into the specification and constitute a part of the specification, showing embodiments consistent with the present disclosure and, together with the specification, used to explain the principles of the present disclosure.

[0021] Figure 1 is a circuit structure diagram of a charging circuit shown according to an exemplary embodiment.

[0022] Figure 2 is a schematic diagram of the current flow direction of a charging circuit shown according to an exemplary embodiment.

[0023] Figure 3 is a circuit structure diagram of a charging circuit shown according to an exemplary embodiment.

[0024] Figure 4 is a schematic diagram of a charging process shown according to an exemplary embodiment. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] Here, the exemplary embodiments will be described in detail, and the examples are shown in the accompanying drawings. When the following description refers to the accompanying drawings, unless otherwise indicated, the same numerals in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present disclosure. On the contrary, they are merely examples of devices and methods consistent with some aspects of the present disclosure as detailed in the appended claims.

[0026] In related technologies, when charging an electronic device, during the high-current charging stage, high-voltage charging is performed. A relatively low current flows into the charge pump at the input end of the charging circuit, and the charge pump then outputs a relatively high current to the battery, resulting in a relatively low load-bearing capacity for the wires of the charging circuit and the charger. When the charging stage enters the low-current direct charging stage, the charging circuit forms a direct charging channel through the existing internal lines of the charge pump. However, the MOS transistors inside the charge pump are first limited by their area, and their impedance is often relatively large. Moreover, they are connected in multiple stages in series, resulting in a relatively large path impedance, and the direct charging effect is often discounted.

[0027] To solve the above technical problems, according to an embodiment of the present disclosure, a charging circuit and an electronic device are provided. The charging circuit is used to supply power to a battery and includes: an input end; a first branch connected between the input end and the battery; a second branch connected between the input end and the battery. The second branch includes a charging element that changes the current flowing into the charging element and outputs it to the battery. When the first branch is conducting and the second branch is disconnected, the input end is connected to the battery through the first branch. When the first branch is disconnected and the second branch is conducting, the input end is connected to the battery through the second branch.

[0028] The present disclosure provides a first branch directly connecting the input end and the battery and a second branch provided with a charging element in the charging circuit, so that, while maintaining a relatively low cost of the charging circuit, the charging circuit can select a direct charging path with a relatively low impedance during the charging process, thereby improving the charging efficiency of the charging circuit during the low-current charging stage.

[0029] It can be understood that the charging circuit involved in the present disclosure can be applied to any one of the following listed terminals.

[0030] It can be understood that the terminal involved in the present disclosure, which can also be referred to as a terminal device, user equipment (UE), mobile station (MS), mobile terminal (MT), etc., is a device that provides voice and / or data connectivity to users. For example, the terminal can be a handheld device with wireless connection function, a vehicle-mounted device, etc. Currently, some examples of terminals are: smart phones (Mobile Phone), pocket personal computers (Pocket Personal Computer, PPC), palm computers, personal digital assistants (Personal Digital Assistant, PDA), laptop computers, tablet computers, wearable devices, or vehicle-mounted devices, etc. In addition, when it is a vehicle-to-everything (V2X) communication system, the terminal device can also be a vehicle-mounted device. It should be understood that the specific technologies and specific device forms adopted by the terminal in the embodiments of the present disclosure are not limited.

[0031] It can be understood that the charging circuit can be used to supply power to the battery. The battery can be a device that converts other forms of energy stored in itself into electrical energy or stores electrical energy by converting electrical energy into other forms of energy.

[0032] Figure 1 It is a circuit structure diagram of a charging circuit shown according to an exemplary embodiment. Figure 2 It is a schematic diagram of the current flow direction of a charging circuit shown according to an exemplary embodiment.

[0033] In some embodiments, such as Figure 1 and Figure 2 shown, the charging circuit may include: an input terminal 100, a first branch 11, and a second branch 12.

[0034] The input terminal 100 can be a port through which current is accessed when the charging circuit enters the charging state. The charging current can be input from the input terminal 100 into the charging circuit, and the input terminal 100 can output the charging current to the battery 200 to charge the battery 200.

[0035] The first branch 11 can be connected between the input terminal 100 and the battery 200, and the second branch 12 can be connected between the input terminal 100 and the battery 200.

[0036] The second branch 12 may include a charging element 40. The charging element 40 can change the current flowing into the charging element 40 and output it to the battery 200. Exemplarily, the input terminal 100 of the charging circuit can input a lower current into the charging element 40, and the charging element 40 then outputs a higher current to the battery 200.

[0037] When the first branch 11 is conducting and the second branch 12 is non-conducting, the input terminal 100 is connected to the battery 200 through the first branch 11, enabling the current at the input terminal 100 to directly charge the battery 200 through the first branch 11.

[0038] When the first branch 11 is non-conducting and the second branch 12 is conducting, the input terminal 100 is connected to the battery 200 through the second branch 12, allowing the current at the input terminal 100 to be processed by the charging element 40 before being input into the battery 200 to meet the charging requirements of the battery 200.

[0039] The present disclosure provides a charging circuit with a first branch 11 directly connecting the input terminal 100 and the battery 200 and a second branch 12 provided with a charging element 40. Thus, while maintaining a relatively low cost of the charging circuit setup, the charging circuit can select a direct charging path with lower impedance during the charging process, thereby improving the charging efficiency of the charging circuit during the low-current charging stage.

[0040] In some embodiments, as Figure 1 and Figure 2 shown, the charging circuit includes a first charging stage and a second charging stage.

[0041] When the charging circuit is in the first charging stage, the first branch 11 is conducting and the second branch 12 is non-conducting, so that the input terminal 100 is connected to the battery 200 through the first branch 11, enabling the current at the input terminal 100 to directly charge the battery 200 through the first branch 11.

[0042] When the charging circuit is in the second charging stage, the first branch 11 is non-conducting and the second branch 12 is conducting, so that the input terminal 100 is connected to the battery 200 through the second branch 12, allowing the current at the input terminal 100 to be processed by the charging element 40 before being input into the battery 200 to meet the charging requirements of the battery 200.

[0043] When the charging circuit is in the first charging stage, the current charged into the battery 200 can be less than or equal to the threshold current. When the charging circuit is in the second charging stage, the current charged into the battery 200 can be greater than the threshold current, where the threshold current can be less than or equal to the rated input current of the input terminal 100.

[0044] The rated input current of the input terminal 100 can be determined by the parameters of the charging circuit wiring, the power adapter, and the power data cable.

[0045] Exemplarily, the rated input current of the input terminal 100 can be the maximum output current of the power adapter.

[0046] When the charging circuit is in the first stage, the maximum output current of the power adapter can meet the charging requirements of the battery 200. At this time, the current input from the input terminal 100 can directly charge the battery 200 through the first branch 11, thereby improving the charging efficiency of the charging circuit.

[0047] When the charging circuit is in the second stage, the charging current required by the battery 200 is greater than that in the first stage, and the maximum output current of the power adapter cannot meet the charging requirements of the battery 200. At this time, the current input from the input terminal 100 can pass through the second branch 12 and flow through the charging element 40 to charge the battery 200, thereby meeting the charging requirements of the battery 200.

[0048] In some embodiments, such as Figure 1 and Figure 2 shown, the charging circuit may include a first switching element 20 disposed on the first branch 11, and the first switching element 20 can be used to control the conduction and disconnection of the first branch 11.

[0049] When the charging circuit is in the first charging stage, the first switching element 20 conducts the first branch 11, so that the input terminal 100 is connected to the battery 200 through the first branch 11. At this time, the current input from the input terminal 100 can directly charge the battery 200 through the first branch 11, thereby improving the charging efficiency of the charging circuit.

[0050] When the charging circuit is in the second charging stage, the first switching element 20 disconnects the first branch 11. At this time, the current input from the input terminal 100 can pass through the second branch 12 and flow through the charging element 40 to charge the battery 200, thereby meeting the charging requirements of the battery 200.

[0051] Figure 3 is a circuit structure diagram of a charging circuit shown according to an exemplary embodiment.

[0052] In some embodiments, such as Figure 3 shown, the charging circuit may include a second switching element 21 disposed on the second branch 12, and the second switching element 21 can be used to control the conduction and disconnection of the second branch 12.

[0053] When the charging circuit is in the second charging stage, the second switching element 21 disconnects the second branch 12. At this time, the current input from the input terminal 100 can directly charge the battery 200 through the first branch 11, thereby improving the charging efficiency of the charging circuit.

[0054] When the charging circuit is in the first charging stage, the second switching element 21 conducts the second branch 12, so that the input terminal 100 is connected to the battery 200 through the second branch 12. At this time, the current input by the input terminal 100 can pass through the second branch 12 and flow through the charging element 40 to charge the battery 200, thereby meeting the charging requirements of the battery 200.

[0055] In some embodiments, when the charging circuit changes from the second charging state to the first charging state, the first branch 11 can change from the off state to the on state, and the second branch 12 can change from the on state to the off state. The state transformation of the first branch 11 and the state transformation of the second branch 12 are separated by a dead time in the switching timing to prevent the first branch 11 and the second branch 12 from conducting simultaneously.

[0056] Based on the same principle, when the charging circuit changes from the first charging state to the second charging state, the state transformation of the first branch 11 and the state transformation of the second branch 12 are separated by a dead time in the switching timing to prevent the first branch 11 and the second branch 12 from conducting simultaneously.

[0057] In some embodiments, as Figure 1 and Figure 2 shown, the charging circuit may include: an overvoltage protection element 30.

[0058] The overvoltage protection element 30 may be disposed between the input terminal 100 and the battery 200. When the voltage input by the input terminal 100 is greater than the threshold voltage, the overvoltage protection element 30 can be disconnected to disconnect the connection between the input terminal 100 and the battery 200. The overvoltage protection element 30 can monitor the current and voltage in the circuit by detecting the magnitudes of the voltage and current in the charging circuit. When the current or voltage value exceeds the specified threshold, the overvoltage protection element 30 can protect the circuit elements and lines by cutting off the circuit.

[0059] In some embodiments, as Figure 1 and Figure 2 shown, the first switching element 20 and the overvoltage protection element 30 may be metal-oxide-semiconductor field effect transistors. The metal-oxide-semiconductor field effect transistor has a low impedance and a fast conduction speed, which can reduce the impedance impact of the switching element on the charging circuit, improve the switching speed of the branches of the charging circuit, and improve the charging efficiency of the charging circuit.

[0060] In some embodiments, the resistance value of the first switching element 20 may be 2 to 5 milliohms. The lower resistance value can reduce the impedance of the first branch 11, thereby reducing the loss of current passing through the first branch 11 and improving the charging efficiency when the charging circuit charges the battery 200 through the first branch 11.

[0061] In some embodiments, asFigure 1 and Figure 2 As shown in Figure 2 , the first switching element 20 may include a first body diode, the overvoltage protection element 30 may include a second body diode, and the anodes of the first body diode and the second body diode are arranged opposite to each other.

[0062] When the metal-oxide-semiconductor field-effect transistor is in the off state, current can still flow through the body diode, resulting in a leakage phenomenon in the direction from the anode to the cathode of the body diode. By arranging the first body diode and the second body diode opposite to each other, the leakage directions of the first body diode and the second body diode can be made opposite, so that when the first switching element 20 and the overvoltage protection element 30 are in the off state, the input terminal 100 will not leak electricity to the battery 200, and the battery 200 will not leak electricity to the input terminal 100.

[0063] In some embodiments, the charging element 40 may be a charge pump. A charge pump is a DC-to-DC converter that can use capacitors for high-energy charge storage to increase or decrease the voltage, thereby increasing the charging rate. The charge pump circuit has high electrical efficiency and reduces power loss during charging.

[0064] The charge pump can turn on or off the second branch 12.

[0065] When the charging circuit is in the second charging stage, the charging element 40 turns off the second branch 12. At this time, the current input from the input terminal 100 can directly charge the battery 200 through the first branch 11, thereby improving the charging efficiency of the charging circuit.

[0066] When the charging circuit is in the first charging stage, the charging element 40 turns on the second branch 12 to connect the input terminal 100 to the battery 200 through the second branch 12. At this time, the current input from the input terminal 100 can directly charge the battery 200 through the first branch 11, thereby improving the charging efficiency of the charging circuit.

[0067] In some embodiments, as Figure 1 and Figure 2 shown, it may further include: a processing unit 300, which is connected to the first switching element 20, and the processing unit 300 can control the on state of the first switching element 20.

[0068] Exemplarily, the processing unit 300 may be a central processing unit or a power control chip.

[0069] In some embodiments, as Figure 1 and Figure 2 shown, the processing unit 300 may be connected to the charging element 40, so that the processing unit 300 can control the on and off of the charging element 40.

[0070] The charging element 40 is connected to the first switching element 20, so that the circuit inside the charging element 40 can serve as the driving circuit of the first switching element 20, enabling the processing unit 300 to control the conduction state of the first switching element 20 through the charging element 40.

[0071] Exemplarily, the processing unit 300 can use the circuit inside the charge pump as the driving circuit of the first switching element 20, and output a high-level signal or a low-level signal to the first switching element 20 through the circuit inside the charge pump, enabling the first switching element 20 to switch its conduction state according to the level of the level signal.

[0072] This improves the device reuse rate of the charging circuit, reduces the supporting cost of setting the first switching element 20, and reduces the total cost of the charging circuit.

[0073] In some embodiments, as Figure 1 and Figure 2 shown, it may further include: a power management integrated circuit 50 and a third branch 13. The power management integrated circuit 50 can be arranged in the third branch 13. One end of the power management integrated circuit 50 is electrically connected to the input terminal 100, and the other end of the power management integrated circuit 50 is electrically connected to the battery 200.

[0074] When the input terminal 100 of the charging circuit is connected to a power adapter with a fixed low output current, the first switching element 20 and the charging element 40 can disconnect the first branch 11 and the second branch 12. The power management integrated circuit 50 can conduct the third branch 13, and the current can flow from the power management integrated circuit 50 into the battery 200. The power management integrated circuit 50 can control the current and voltage input to the battery 200 by the third branch 13 according to the charging requirements of the battery 200, so that the current input from the input terminal 100 can meet the charging requirements of the battery 200.

[0075] Figure 4 is a schematic diagram of a charging process shown according to an exemplary embodiment.

[0076] In some embodiments, as Figure 4 shown, the processing unit 300 can detect the charging current required by the battery 200. When the charging current is less than or equal to the threshold current, the charging circuit can switch to direct charging through the first branch. Switching to direct charging through the first branch can be understood as the charging circuit being in the first charging stage. The first switching element 20 conducts the first branch 11, and the charging element 40 disconnects the second branch 12. At this time, the current input from the input terminal 100 can directly charge the battery 200 through the first branch 11, thereby improving the charging efficiency of the charging circuit.

[0077] When the charging current is greater than the threshold current, the charging circuit can maintain charge pump charging. Maintaining charge pump charging can be understood as the charging circuit being in the second charging stage. The first switching element 20 disconnects the first branch 11, and the charging element 40 conducts the second branch 12, so that the input terminal 100 is connected to the battery 200 through the second branch 12. At this time, the current at the input terminal 100 can be processed by the charging element 40 and then input into the battery 200 to meet the charging requirements of the battery 200.

[0078] Based on the same concept, the embodiments of the present disclosure also provide an electronic device.

[0079] Among them, the electronic device can be a laptop computer, a desktop computer, a mobile phone, a digital broadcast terminal, a messaging device, a game console, a tablet device, a medical device, a fitness device, a personal digital assistant, a translator, and wearable devices such as watches and bracelets, etc., and can be any electronic device with a charging circuit. In the following description, a mobile phone is taken as an example for illustration, but the present disclosure is not limited thereto.

[0080] In some embodiments, the electronic device may include a charging circuit. When the electronic device is connected to a power adapter, the current of the power adapter can be charged into the battery 200 through the charging circuit.

[0081] In some embodiments, the electronic device may include: a main board and a charging chip, and the main board may be provided with a first switching element 20.

[0082] The charging chip may be disposed on the main board, and the charging chip includes a charging element 40 and a power management integrated circuit 50.

[0083] By disposing the first switching element 20 on the main board, the volume of the first switching element 20 can no longer be limited by the package size of the charging chip. The first switching element 20 with a larger volume can have a smaller resistance value, thereby improving the charging efficiency of the charging circuit.

[0084] It can be understood that in the present disclosure, "a plurality of" means two or more, and other quantifiers are similar. "And / or" describes the association relationship of associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. The character " / " generally represents an "or" relationship between the associated objects before and after. The singular forms of "a", "the", and "said" are also intended to include the plural forms unless the context clearly indicates otherwise.

[0085] It can be further understood that the terms "second", "second", etc. are used to describe various information, but such information should not be limited to these terms. These terms are only used to distinguish information of the same type from each other, and do not indicate a specific order or degree of importance. In fact, expressions such as "second", "second", etc. can be used interchangeably completely. For example, without departing from the scope of the present disclosure, the second information can also be referred to as the second information, and similarly, the second information can also be referred to as the second information.

[0086] It can be further understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "front", "rear", "upper", "lower", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present embodiment and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation.

[0087] It can be further understood that unless otherwise specified, "connection" includes direct connection without other components between the two, and also includes indirect connection with other elements between the two.

[0088] It can be further understood that although the operations are described in a specific order in the drawings in the embodiments of the present disclosure, it should not be understood as requiring these operations to be performed in the specific order shown or in a serial order, or requiring all the operations shown to obtain the desired result. In a specific environment, multitasking and parallel processing may be advantageous.

[0089] Those skilled in the art will readily conceive of other embodiments of the present disclosure after considering the specification and practicing the utility model disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present disclosure, which follow the general principles of the present disclosure and include well-known knowledge or conventional technical means in the technical field not disclosed in the present disclosure. The specification and embodiments are only regarded as exemplary, and the true scope and spirit of the present disclosure are pointed out by the following claims.

[0090] It should be understood that the present disclosure is not limited to the exact structures described above and shown in the drawings, and various modifications and changes can be made without departing from its scope. The scope of the present disclosure is only limited by the appended claims.

Claims

1. A charging circuit, characterized in that: The charging circuit is used to supply power to the battery, and comprises: Input terminal; a first branch, the first branch being connected between the input terminal and the battery; a second branch, the second branch being connected between the input terminal and the battery, the second branch comprising a charging element, the charging element changing the current flowing into the charging element and outputting it to the battery; When the first branch is turned on and the second branch is turned off, the input end is connected to the battery through the first branch; When the first branch is disconnected and the second branch is turned on, the input end is connected to the battery through the second branch.

2. The charging circuit according to claim 1, characterized in that: The charging stage of the charging circuit includes a first charging stage and a second charging stage; When the charging circuit is in the first charging stage, the input end is connected to the battery through the first branch, and the current charged into the battery is less than or equal to a threshold current; When the charging circuit is in the second charging stage, the input terminal is connected to the battery through the second branch, and the current charged into the battery is greater than the threshold current. The threshold current is less than or equal to the rated input current of the input end.

3. The charging circuit according to claim 2, characterized in that: The charging circuit includes a first switching element arranged in the first branch, Wherein, when the charging circuit is in the first charging stage, the first switching element turns on the first branch so that the input end is connected to the battery through the first branch; When the charging circuit is in the second charging stage, the first switching element disconnects the first branch.

4. The charging circuit according to claim 2, characterized in that: The charging circuit includes a second switching element arranged in the second branch, Wherein, when the charging circuit is in the second charging stage, the second switching element disconnects the second branch; When the charging circuit is in the first charging stage, the second switching element turns on the second branch so that the input end is connected to the battery through the second branch.

5. The charging circuit according to claim 3, characterized in that: The charging circuit comprises: An overvoltage protection element is provided between the input terminal and the battery. When the voltage input to the input terminal is greater than a threshold voltage, the overvoltage protection element is disconnected to disconnect the input terminal from the battery.

6. The charging circuit according to claim 5, characterized in that: The first switching element and the overvoltage protection element are metal-oxide semiconductor field effect transistors.

7. The charging circuit according to claim 6, characterized in that: The first switching element includes a first body diode, the overvoltage protection element includes a second body diode, and an anode of the first body diode is arranged opposite to an anode of the second body diode.

8. The charging circuit according to claim 7, characterized in that: The charging element is a charge pump; When the charging circuit is in the second charging stage, the charging element disconnects the second branch; When the charging circuit is in the first charging stage, the charging element turns on the second branch so that the input terminal is connected to the battery through the second branch.

9. The charging circuit according to claim 3, characterized in that: Also includes: A processing unit is connected to the first switching element, and the processing unit controls a conducting state of the first switching element.

10. The charging circuit according to claim 9, characterized in that: The processing unit is connected to the charging element, and the processing unit controls the on and off of the charging element; The charging element is connected to the first switching element, and the processing unit controls the conduction state of the first switching element through the charging element.

11. The charging circuit according to claim 1, characterized in that: Also includes: A power management integrated circuit, one end of the power management integrated circuit is electrically connected to the input end, and the other end of the power management integrated circuit is electrically connected to the battery.

12. An electronic device, characterized in that: include: A charging circuit as claimed in any one of claims 1 to 11.

13. The electronic device according to claim 12, characterized in that: The electronic device comprises: A main board, wherein the main board is provided with a first switching element; A charging chip is arranged on the mainboard, and the charging chip includes the charging element and a power management integrated circuit.

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