Charging circuit, chip and electronic equipment

Abstract

The embodiment of the utility model provides a charging circuit, a chip and an electronic device, the charging circuit comprises a current limiting module, an anti-short-circuit module and a switch module, the positive end voltage of a battery pack is monitored in real time through the control end of the switch module, and when the positive end voltage of the battery pack is reduced to a certain degree, the switch module can be disconnected, and the battery pack is charged. Therefore, the power supply end can charge the battery pack in time through the current limiting module and the anti-short-circuit module, the battery pack is prevented from becoming a dead battery, or even if the battery pack becomes a dead battery, the switch module can be controlled to be switched off, and the battery pack is charged through the current limiting module and the anti-short-circuit module.

Description

Technical Field

[0001] The present application relates to the technical field of electronic circuits, and in particular to a charging circuit, a chip and an electronic device. Background Art

[0002] In some power supply environments, the power supply is completed by the battery pack. When the system is not used for a long time, the static power consumption will continuously consume the voltage of the battery pack, causing the voltage of the battery pack to drop to a very low potential, or even 0V, resulting in the battery pack being unable to supply power to the control chip normally, and thus unable to charge the battery pack through the main charging circuit under the control of the control chip. This situation is also called a dead battery.

[0003] Therefore, there is an urgent need to provide a charging circuit that can avoid becoming a dead battery or can charge a dead battery. Utility Model Content

[0004] In view of the above problems, the embodiments of the present application provide a charging circuit, a chip and an electronic device to solve the above technical problems.

[0005] In the first aspect, an embodiment of the present application provides a charging circuit, which includes a current limiting module, an anti-short circuit module and a switch module, wherein the first end of the current limiting module is connected to the power supply end; the first end of the anti-short circuit module is connected to the second end of the current limiting module, and the second end of the anti-short circuit module is used to connect to the positive end of the battery pack; the first end of the switch module is connected to the first end of the anti-short circuit module and the second end of the current limiting module, the control end of the switch module is used to connect to the positive end of the battery pack, the second end of the switch module is connected to the negative end and the ground end of the battery pack, and the switch module is used to control whether to charge the battery pack according to the positive terminal voltage of the battery pack.

[0006] In a second aspect, an embodiment of the present application further provides a chip, which includes the above-mentioned charging circuit.

[0007] In a third aspect, an embodiment of the present application further provides an electronic device, which includes a device body and the above-mentioned chip or charging circuit provided in the device body.

[0008] The charging circuit, chip and electronic device provided in the embodiments of the present application monitor the positive terminal voltage of the battery pack in real time through the control end of the switch module. When the positive terminal voltage of the battery pack drops to a certain level, the switch module can be disconnected, so that the power supply end can charge the battery pack in time through the current limiting module and the anti-short circuit module, thereby preventing the battery pack from becoming a dead battery. Alternatively, even if the battery pack becomes a dead battery, the switch module can be controlled to disconnect, and the battery pack can be charged through the current limiting module and the anti-short circuit module.

[0009] Moreover, compared with the larger fluctuation of charging current, the peak value of charging current is higher, which will seriously affect the battery life. The present application can perform trickle charging for dead batteries through the current limiting module, which is beneficial to improve the life and safety of the battery pack.

[0010] Furthermore, the anti-short circuit module can prevent the positive terminal and the negative terminal of the battery pack from being short-circuited when the switch module is turned on, thereby providing charging safety.

[0011] These and other aspects of the present application will become more clearly understood in the description of the following embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0013] Figure 1 A first principle block diagram of a charging circuit provided in an embodiment of the present application is shown.

[0014] Figure 2 The circuit schematic diagram of the current limiting module and the anti-short circuit module is shown.

[0015] Figure 3 The schematic diagram of the switch module is shown.

[0016] Figure 4 A second principle block diagram of a charging circuit provided in an embodiment of the present application is shown.

[0017] Figure 5 A first circuit schematic diagram of a boost module is shown.

[0018] Figure 6 A second circuit schematic diagram of a boost module is shown.

[0019] Figure 7 A third principle block diagram of the charging circuit provided in an embodiment of the present application is shown.

[0020] Figure 8 A first circuit schematic diagram of a charging threshold control module is shown.

[0021] Fig. 9 A second circuit schematic diagram of the charging threshold control module is shown.

[0022] Fig.10 A first circuit schematic diagram of a charging circuit provided in an embodiment of the present application is shown.

[0023] Fig.11A second circuit schematic diagram of a charging circuit provided in an embodiment of the present application is shown.

[0024] Fig.12 A schematic diagram showing the current path of the charging circuit in the charging state.

[0025] Fig.13 A schematic diagram of the current path of the charging circuit in the first off state is shown.

[0026] Fig.14 A schematic diagram of the current path of the charging circuit in the second off state is shown.

[0027] Fig.15 A schematic diagram of the structure of a chip provided in an embodiment of the present application is shown.

[0028] Fig.16 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0029] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.

[0030] In order to enable those skilled in the art to better understand the solutions of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present application.

[0031] In the embodiments of the present application, it should be noted that, in this article, relational terms such as first and second, etc. are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations.

[0032] Moreover, the terms "comprises," "comprising," or any other variation thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.

[0033] In the description of the embodiments of the present application, words such as "example" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "example" or "for example" in the embodiments of the present application is not to be interpreted as being more preferred or having more advantages than another embodiment or design. The use of words such as "example" or "for example" is intended to present relative concepts in a clear manner.

[0034] In addition, the "plurality" in the embodiments of the present application refers to two or more than two. In view of this, in the embodiments of the present application, "plurality" can also be understood as "at least two". "At least one" can be understood as one or more, for example, one, two or more. For example, including at least one means including one, two or more, and there is no limit on which ones are included. For example, including at least one of A, B and C, then A, B, C, A and B, A and C, B and C, or A, B and C can be included.

[0035] It should be noted that, in the embodiments of the present application, "and / or" describes the association relationship of the associated objects, indicating that three relationships may exist. For example, A and / or B may represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / ", unless otherwise specified, generally indicates that the associated objects before and after are in an "or" relationship.

[0036] It should be noted that in the embodiments of the present application, "connection" can be understood as electrical connection, and the connection between two electrical components can be a direct or indirect connection between the two electrical components. For example, the connection between A and B can be either a direct connection between A and B or an indirect connection between A and B through one or more other electrical components.

[0037] The first pole / first end of each transistor used in the embodiments of the present application is one of the source and the drain, and the second pole / second end of each transistor is the other of the source and the drain. Since the source and drain of the transistor can be symmetrical in structure, the source and drain thereof can be structurally indistinguishable, that is, the first pole / first end and the second pole / second end of the transistor in the embodiments of the present application can be structurally indistinguishable. Exemplarily, in the case where the transistor is a P-type transistor, the first pole / first end of the transistor is the source, and the second pole / second end is the drain; exemplarily, in the case where the transistor is an N-type transistor, the first pole / first end of the transistor is the drain, and the second pole / second end is the source.

[0038] In the related art, only a main charging circuit is designed for charging the battery pack. After continuous static power consumption, when the voltage of the battery pack drops to a certain level, it is unable to provide a normal operating voltage for the control module, resulting in the inability to control the main charging circuit to charge the battery pack through the control module. In other words, the battery pack cannot be charged and becomes a dead battery.

[0039] In view of this, Figure 1 The first principle block diagram of the charging circuit 100 provided by the embodiment of the present application is shown. The charging circuit 100 includes a current limiting module 10, an anti-short circuit module 20 and a switch module 30. The positive terminal voltage of the battery pack 40 is monitored in real time through the control end of the switch module 30. When the positive terminal voltage of the battery pack 40 drops to a certain level, the switch module 30 can be disconnected, so that the power supply terminal VIN can charge the battery pack 40 in time through the current limiting module 10 and the anti-short circuit module 20, thereby preventing the battery pack 40 from becoming a dead battery. Alternatively, even if the battery pack 40 becomes a dead battery, the switch module 30 can be controlled to be disconnected, and the battery pack 40 can be charged through the current limiting module 10 and the anti-short circuit module 20.

[0040] The present application embodiment provides a charging circuit 100. Figures 1 to 14 ,like Figure 1 As shown, the charging circuit 100 includes a current limiting module 10, an anti-short circuit module 20 and a switch module 30. The first end of the current limiting module 10 is connected to the power supply terminal VIN; the first end of the anti-short circuit module 20 is connected to the second end of the current limiting module 10, and the second end of the anti-short circuit module 20 is used to connect to the positive end of the battery pack 40; the first end of the switch module 30 is connected to the first end of the anti-short circuit module 20 and the second end of the current limiting module 10, the control end of the switch module 30 is used to connect to the positive end of the battery pack 40, and the second end of the switch module 30 is connected to the negative end of the battery pack 40 and the ground terminal GND.

[0041] It can be understood that the charging circuit 100 provided in the embodiment of the present application monitors the positive terminal voltage of the battery pack 40 in real time through the control end of the switch module 30. When the positive terminal voltage of the battery pack 40 drops to a certain level, the switch module 30 can be disconnected, so that the power supply terminal VIN can charge the battery pack 40 in time through the current limiting module 10 and the anti-short circuit module 20, thereby preventing the battery pack 40 from becoming a dead battery. Alternatively, even if the battery pack 40 becomes a dead battery, the switch module 30 can be controlled to be disconnected, and the battery pack 40 can be charged through the current limiting module 10 and the anti-short circuit module 20.

[0042] Moreover, compared with the larger fluctuation of the charging current, the peak value of the charging current is higher, which will seriously affect the life of the battery BA1. The present application can perform trickle charging for the dead battery through the current limiting module 10, which is beneficial to improve the life and safety of the battery pack 40.

[0043] Furthermore, the anti-short circuit module 20 can prevent the positive terminal and the negative terminal of the battery pack 40 from being short-circuited when the switch module 30 is turned on, thereby providing charging safety.

[0044] It should be noted that the switch module 30 is used to control whether to charge the battery pack 40 according to the positive terminal voltage of the battery pack 40. For example, when the positive terminal voltage of the battery pack 40 is less than or equal to the preset voltage, the switch module 30 is disconnected, and the current provided by the power supply terminal VIN charges the battery pack 40 through the current limiting module 10 and the anti-short circuit module 20; when the positive terminal voltage of the battery pack 40 is greater than the preset voltage, the switch module 30 is turned on, and the current provided by the power supply terminal VIN flows to the negative terminal of the battery pack 40 and the ground terminal GND through the current limiting module 10 and the switch module 30.

[0045] Alternatively, if Figure 2 As shown, the current limiting module 10 includes a first resistor R1, a first end of the first resistor R1 is connected to the power supply terminal VIN, and a second end of the first resistor R1 is connected to a first end of the anti-short circuit module 20 and a first end of the switch module 30. The anti-short circuit module 20 includes a first diode D1, an anode of the first diode D1 is connected to the second end of the first resistor R1 and a first end of the switch module 30, and a cathode of the first diode D1 is connected to the positive end of the battery pack 40.

[0046] It should be noted that the use of the first resistor R1 to form the current limiting module 10 and the use of the first diode D1 to form the anti-short circuit module 20 can simplify the structure of the charging circuit 100. Exemplarily, the first resistor R1 is an adjustable resistor to achieve different trickle current charging.

[0047] Alternatively, if Figure 3 As shown, the switch module 30 includes a first transistor Q1, a first electrode of the first transistor Q1 is connected to the second end of the first resistor R1 and the positive electrode of the first diode D1, a control electrode of the first transistor Q1 is connected to the cathode of the first diode D1 and the positive end of the battery pack 40, and a second electrode of the first transistor Q1 is connected to the negative end of the battery pack 40 and the ground end GND.

[0048] It should be noted that the first transistor Q1 can be an N-channel triode or field effect transistor. When the positive terminal voltage of the battery pack 40 drops to a certain value, the first transistor Q1 will be disconnected, thereby trickle charging the battery pack 40 through the first resistor R1 and the first diode D1. When the positive terminal voltage of the battery pack 40 is greater than the fixed value, the first transistor Q1 will be turned on, so that the power supply terminal VIN forms a loop through the first resistor R1, the first transistor Q1 and the ground terminal GND, and the battery pack 40 will not be charged.

[0049] Alternatively, if Figure 4 As shown, the charging circuit 100 further includes a boost module 50 , which is connected between the negative terminal of the battery pack 40 and the ground terminal GND.

[0050] It should be noted that the boost module 50 can increase the negative terminal voltage of the battery pack 40 , thereby increasing the positive terminal voltage of the battery pack 40 , thereby enabling normal power supply even when the voltage of the battery pack 40 is low.

[0051] Alternatively, if Figure 5 As shown, the boost module 50 includes a first boost unit 51, and the first boost unit 51 includes at least one second diode D2 connected in series, the positive electrode of the second diode D2 is connected to the negative end of the battery pack 40 and the second electrode of the first transistor Q1, and the negative electrode of the second diode D2 is connected to the ground terminal GND.

[0052] It should be noted that the first boost unit 51 can increase the negative terminal voltage of the battery pack 40, thereby increasing the positive terminal voltage of the battery pack 40, and further enabling normal power supply when the voltage of the battery pack 40 is low. In the case where there are multiple second diodes D2, the multiple second diodes D2 are connected in series head to tail in order to boost the voltage as needed.

[0053] Alternatively, if Figure 6 As shown, the boost module 50 further includes a second boost unit 52, which includes a second resistor R2, a first end of the second resistor R2 is connected to the cathode of the second diode D2, and a second end of the second resistor R2 is connected to the ground terminal GND.

[0054] It should be noted that, in other embodiments, the first boost unit 51 and the second boost unit 52 may also be interchanged, for example, the second boost unit 52 may be located between the first boost unit 51 and the negative terminal of the battery pack 40. The structure of the first boost unit 51 may be the same as or different from that of the second boost unit 52. The second resistor R2 may not only boost the voltage, but also limit the current together with the first resistor R1.

[0055] Alternatively, if Figure 7 As shown, the charging circuit 100 further includes a charging threshold control module 60 , and the charging threshold control module 60 is connected to the switch module 30 and the battery pack 40 .

[0056] It should be noted that the charging threshold control module 60 can be used to adjust the positive terminal voltage of the battery pack 40 to disconnect the switch module 30 when the charging threshold is reached.

[0057] Alternatively, if Figure 8 As shown, the charging threshold control module 60 includes a first charging threshold control unit 61, which includes a third resistor R3, a first end of the third resistor R3 is connected to the positive end of the battery pack 40, and a second end of the third resistor R3 is connected to the control electrode of the first transistor Q1.

[0058] It should be noted that the third resistor R3 can adjust the positive terminal voltage of the battery pack 40 to transmit to the control electrode voltage of the first transistor Q1 through its own voltage drop, thereby controlling the on and off of the first transistor Q1.

[0059] Alternatively, if Fig. 9 As shown, the charging threshold control module 60 also includes a second charging threshold control unit 62, which includes a fourth resistor R4, a first end of the fourth resistor R4 is connected to the second end of the third resistor R3, and a second end of the fourth resistor R4 is connected to the negative end of the battery pack 40.

[0060] It should be noted that the third resistor R3 and the fourth resistor R4 can control the on / off of the switch module 30 after dividing the positive terminal voltage of the battery pack 40 , so as to adjust the charging threshold of the battery pack 40 .

[0061] Alternatively, if Fig.10 As shown, the charging circuit 100 also includes a protection module 70, a power supply pin (VDD) of the protection module 70 is connected to the positive terminal of the battery pack 40, a ground pin (GND) of the protection module 70 is connected to the negative terminal of the battery pack 40, and a current detection pin (VM) of the protection module 70 is connected to the ground terminal GND.

[0062] It should be noted that the protection module 70 may be: Fig.10 The protection chip U1 of the battery pack 40 shown has at least one of the functions of undervoltage protection, overvoltage protection, overcurrent protection, etc.

[0063] like Fig.10 As shown, the battery pack 40 may include at least one battery BA1. In the case of multiple batteries BA1, these batteries BA1 may be connected in series and / or in parallel. The battery BA1 is a rechargeable battery BA1.

[0064] exist Fig.11 In the embodiment, the charging circuit 100 may further include a first switch S1, a charger 80 and a control module 90, wherein the first end of the first switch S1 is connected to the power supply end VIN, the second end of the first switch S1 is connected to the first end of the charger 80, the second end of the charger 80 is connected to the positive end of the battery pack 40, and the control module 90 is connected to the positive end of the battery pack 40, the control end of the first switch S1 and the ground end GND.

[0065] The first switch S1 and the charger 80 may constitute a main charging circuit for charging the battery pack 40. The battery pack 40 supplies power to the control module 90, and the control module 90 controls the on and off of the first switch S1. VBAT represents the positive terminal voltage of the battery pack 40. The control module 90 may be a microcontroller unit (MCU) or the like.

[0066] Among them, Fig.11 In the embodiment, the second diode D2 and the third diode D3 may together form a first boost unit 51 to adjust the negative terminal voltage of the battery pack 40 .

[0067] The charging circuit 100 of the present application has three working states: a charging state, a first off state, and a second off state, which are specifically described as follows:

[0068] Charging status: Fig.10 , Fig.12 As shown, when the voltage of the battery BA1 is low, it cannot normally supply power to the control module 90, causing the first switch S1 to be unable to close, and the main charging circuit cannot charge the battery pack 40. In this case, the first transistor Q1 is turned off, and the protection chip U1 is also in an undervoltage protection state; at this time, the adapter is inserted to supply power to the power supply terminal VIN, such as Fig.12 As shown by the dotted arrow in FIG. 1 , the current will form a loop through the first resistor R1 , the first diode D1 , the battery pack 40 , the second diode D2 , and the second resistor R2 to trickle charge the battery pack 40 or the dead battery.

[0069] First off state: Fig.11 , Fig.13 As shown in FIG. 1 , as the dead battery is charged, the voltage of the battery BA1 continues to increase, and the gate voltage of the first transistor Q1 also increases to the state of being turned on, but the voltage of the battery BA1 does not reach the state of releasing the undervoltage protection of the protection chip U1. Fig.13As shown by the dotted arrow in , the current forms a loop through the first resistor R1, the first transistor Q1, the second diode D2, and the second resistor R2, and the battery BA1 is not charged, and the charging circuit 100 is in the first off state. However, at this time, the main charging circuit will continue to charge the battery BA1 through the first switch S1 and the charger 80, and the charging current at this time is higher than the dead battery charging current, but lower than the normal constant current charging current.

[0070] Second off state: Fig.10 , Fig.14 As shown, as the voltage of the battery BA1 continues to increase, the voltage of the battery BA1 reaches the state where the protection chip U1 releases the undervoltage protection state. At this time, the protection chip U1 works normally, such as Fig.14 As shown by the dotted arrow in , the current flows back from the low-voltage side switch tube inside the protection chip U1 through the first resistor R1 and the first transistor Q1, and the battery BA1 enters the normal charging mode.

[0071] The working state of the charging circuit 100 of the present application is automatically switched according to the circuit characteristics, without the need for additional control, thus reducing the control difficulty.

[0072] like Fig.15 As shown, the embodiment of the present application further provides a chip 200, and the chip 200 includes the above-mentioned charging circuit 100. The chip 200 is also called an integrated circuit (IC), and the chip 200 can be, but is not limited to, a SOC (System on Chip) chip or a SIP (system in package) chip.

[0073] It can be understood that since the chip 200 provided in the embodiment of the present application includes a charging circuit 100, it can also monitor the positive terminal voltage of the battery pack 40 in real time through the control end of the switch module 30. When the positive terminal voltage of the battery pack 40 drops to a certain level, the switch module 30 can be disconnected, so that the power supply terminal VIN can charge the battery pack 40 in time through the current limiting module 10 and the anti-short circuit module 20, thereby preventing the battery pack 40 from becoming a dead battery. Alternatively, even if the battery pack 40 becomes a dead battery, the switch module 30 can be controlled to be disconnected, and the battery pack 40 can be charged through the current limiting module 10 and the anti-short circuit module 20.

[0074] Moreover, compared with the larger fluctuation of the charging current, the peak value of the charging current is higher, which will seriously affect the life of the battery BA1. The present application can perform trickle charging for the dead battery through the current limiting module 10, which is beneficial to improve the life and safety of the battery pack 40.

[0075] Furthermore, the anti-short circuit module 20 can prevent the positive terminal and the negative terminal of the battery pack 40 from being short-circuited when the switch module 30 is turned on, thereby providing charging safety.

[0076] like Fig.16 As shown, the embodiment of the present application also provides an electronic device 300, which includes a device body and the above-mentioned chip 200 or charging circuit 100 provided in the device body. The electronic device 300 can be, but is not limited to, a weight scale, a body fat scale, a nutrition scale, an infrared electronic thermometer, a pulse oximeter, a human body composition analyzer, a mobile power supply, a wireless charger 80, a fast charging charger 80, a car charger 80, an adapter, a display, a USB (Universal Serial Bus) docking station, a stylus, a true wireless headset, a car central control screen, a car, a smart wearable device, a mobile terminal, and a smart home device. Smart wearable devices include, but are not limited to, smart watches, smart bracelets, and cervical massagers. Mobile terminals include, but are not limited to, smart phones, laptops, tablet computers, and POS (point of sales terminal). Smart home devices include, but are not limited to, smart sockets, smart rice cookers, smart sweepers, and smart lights.

[0077] It can be understood that since the electronic device 300 provided in the embodiment of the present application includes a chip 200 or a charging circuit 100, it can also monitor the positive terminal voltage of the battery pack 40 in real time through the control end of the switch module 30. When the positive terminal voltage of the battery pack 40 drops to a certain level, the switch module 30 can be disconnected, so that the power supply terminal VIN can charge the battery pack 40 in time through the current limiting module 10 and the anti-short circuit module 20, thereby preventing the battery pack 40 from becoming a dead battery. Alternatively, even if the battery pack 40 becomes a dead battery, the switch module 30 can be controlled to be disconnected, and the battery pack 40 can be charged through the current limiting module 10 and the anti-short circuit module 20.

[0078] Moreover, compared with the larger fluctuation of the charging current, the peak value of the charging current is higher, which will seriously affect the life of the battery BA1. The present application can perform trickle charging for the dead battery through the current limiting module 10, which is beneficial to improve the life and safety of the battery pack 40.

[0079] Furthermore, the anti-short circuit module 20 can prevent the positive terminal and the negative terminal of the battery pack 40 from being short-circuited when the switch module 30 is turned on, thereby providing charging safety.

[0080] The above are only preferred embodiments of the present application, and are not intended to limit the present application in any form. Although the present application has been disclosed as above with preferred embodiments, it is not intended to limit the present application. Any technical personnel in the field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present application. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present application without departing from the content of the technical solution of the present application are still within the scope of the technical solution of the present application.

Claims

1. A charging circuit, characterized in that: The charging circuit comprises: A current limiting module, wherein a first end of the current limiting module is connected to a power supply end; An anti-short circuit module, wherein a first end of the anti-short circuit module is connected to a second end of the current limiting module, and a second end of the anti-short circuit module is connected to a positive end of a battery pack; A switch module, wherein the first end of the switch module is connected to the first end of the anti-short circuit module and the second end of the current limiting module, the control end of the switch module is connected to the positive end of the battery pack, the second end of the switch module is connected to the negative end and the ground end of the battery pack, and the switch module is used to control whether to charge the battery pack according to the positive terminal voltage of the battery pack.

2. The charging circuit according to claim 1, characterized in that: When the voltage at the positive terminal of the battery pack is less than or equal to a preset voltage, the switch module is disconnected, and the current provided by the power supply end charges the battery pack via the current limiting module and the anti-short circuit module; When the voltage at the positive terminal of the battery pack is greater than a preset voltage, the switch module is turned on, and the current provided by the power supply end flows to the negative terminal of the battery pack and the ground terminal through the current limiting module and the switch module.

3. The charging circuit according to claim 1, characterized in that: The current limiting module comprises a first resistor, a first end of the first resistor is connected to the power supply end, and a second end of the first resistor is connected to a first end of the anti-short circuit module and a first end of the switch module; The anti-short circuit module includes a first diode, an anode of the first diode is connected to the second end of the first resistor and the first end of the switch module, and a cathode of the first diode is connected to the positive end of the battery pack.

4. The charging circuit according to claim 3, characterized in that: The switch module includes a first transistor, a first electrode of the first transistor is connected to the second end of the first resistor and the positive electrode of the first diode, a control electrode of the first transistor is connected to the cathode of the first diode and the positive end of the battery pack, and a second electrode of the first transistor is connected to the negative end of the battery pack and the ground end.

5. The charging circuit according to claim 1, characterized in that: The charging circuit further includes a boost module, which is connected between the negative terminal of the battery pack and the ground terminal.

6. The charging circuit according to claim 5, characterized in that: The boost module includes a first boost unit, the first boost unit includes at least one second diode connected in series, the anode of the second diode is connected to the negative end of the battery pack and the second end of the switch module, and the cathode of the second diode is connected to the ground end.

7. The charging circuit according to claim 6, characterized in that: The boost module further includes a second boost unit, the second boost unit includes a second resistor, a first end of the second resistor is connected to the cathode of the second diode, and a second end of the second resistor is connected to the ground end.

8. The charging circuit according to claim 1, characterized in that: The charging circuit further comprises a charging threshold control module, and the charging threshold control module is connected to the switch module and the battery pack.

9. The charging circuit according to claim 8, characterized in that: The charging threshold control module includes a first charging threshold control unit, which includes a third resistor, a first end of the third resistor is connected to the positive end of the battery pack, and a second end of the third resistor is connected to the control end of the switch module.

10. The charging circuit according to claim 9, characterized in that: The charging threshold control module also includes a second charging threshold control unit, which includes a fourth resistor, a first end of the fourth resistor is connected to the second end of the third resistor and the control end of the switch module, and a second end of the fourth resistor is connected to the negative end of the battery pack.

11. The charging circuit according to any one of claims 1 to 10, characterized in that: The charging circuit also includes a protection module, a power supply pin of the protection module is connected to the positive terminal of the battery pack, a ground pin of the protection module is connected to the negative terminal of the battery pack, and a current detection pin of the protection module is connected to the ground terminal.

12. A chip, characterized in that: The chip includes the charging circuit according to any one of claims 1 to 11.

13. An electronic device, characterized in that: The electronic device comprises a device body and the chip according to claim 12 disposed in the device body.

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