Small-capacity battery adjusting protection circuit
By designing a small-capacity battery regulation and protection circuit, combined with a CPU module and power management integrated circuit, the problems of over-discharge and over-charge of small-capacity batteries are solved, enabling real-time monitoring and safety protection of battery status, extending battery life and improving equipment safety.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-20
- Publication Date
- 2026-03-17
AI Technical Summary
Existing battery management systems suffer from detection delays and insufficient accuracy in the charge and discharge control of small-capacity batteries, leading to frequent over-discharge and over-charge phenomena, which affect battery life and pose safety hazards.
A small-capacity battery regulation and protection circuit was designed, including a CPU module, a charge/discharge switching control circuit and a power management integrated circuit. It is connected via an I2C interface to monitor the battery status in real time and avoid over-discharge and over-charge.
It enables real-time and accurate monitoring of small-capacity batteries, preventing rechargeable batteries from bulging, extending battery life, improving equipment safety performance, and optimizing battery management efficiency.
Smart Images
Figure CN224006499U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of charging circuit technology, specifically to a small-capacity battery regulation and protection circuit. Background Technology
[0002] With the continuous development of technology, tablet devices have become an indispensable part of people's daily lives due to their portability and multifunctionality. Our company focuses on the research and development and production of tablet devices with small-capacity batteries. These devices are widely welcomed by the market for their slim design and high performance. However, in daily use, small-capacity batteries are prone to over-discharge and over-charge problems. These problems not only affect the battery's lifespan but may also cause the battery to bulge, and in severe cases, even pose safety hazards.
[0003] To address these issues, researchers and manufacturers in the industry have conducted extensive research and experimentation. For example, some existing battery management systems (BMS) monitor battery voltage and current to control battery charging and discharging. However, these systems are often designed for large-capacity batteries, and their control precision and response speed may not meet the practical needs of small-capacity batteries, resulting in persistent over-discharge and over-charge problems.
[0004] Specifically, existing battery management systems (BMS) have a certain delay in detecting battery status, making it impossible to accurately determine the battery's charge / discharge state in real time. When the battery is over-discharged or overcharged, the system may not be able to take timely protective measures, leading to problems such as battery bulging. Furthermore, small-capacity batteries, due to their smaller capacity, require higher control precision. Therefore, a regulation and protection circuit for small-capacity batteries needs to be designed. Utility Model Content
[0005] This invention addresses the shortcomings and deficiencies of existing technologies by providing a regulation and protection circuit for small-capacity batteries that prevents battery bulging caused by over-discharge and over-charge.
[0006] To achieve the above objectives, the present invention provides a small-capacity battery regulation and protection circuit for protecting the rechargeable battery when it is connected to a charging device for charging. The circuit includes a CPU module, a charge / discharge switching control circuit, and a power management integrated circuit. The power management integrated circuit is disposed between the charging device and the rechargeable battery. The output terminal of the charging device is electrically connected to the input terminal of the power management integrated circuit, and the input terminal of the rechargeable battery is electrically connected to the output terminal of the power management integrated circuit. The CPU module and the power management integrated circuit are connected via an I2C interface, and the charge / discharge switching control circuit is electrically connected to the charging device.
[0007] Further; the power management integrated circuit includes a power management chip, a crystal oscillator, a first inductor, a first MOSFET, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor, a sixth capacitor, a seventh capacitor, an eighth capacitor, a ninth capacitor, a tenth capacitor, an eleventh capacitor, a twelfth capacitor, a first resistor, a second resistor, a third resistor, a fourth resistor, and a fifth resistor; one end of the first capacitor is grounded, and the other end is electrically connected to the fifty-fourth pin of the power management chip; one end of the second capacitor is grounded, and the other end is electrically connected to the fifty-fifth pin of the power management chip; the sixty-ninth pin and the forty-seventh pin of the power management chip are connected in series, and the common terminal of the sixty-ninth pin and the forty-seventh pin of the power management chip is grounded; one end of the third capacitor is grounded, and the other end is connected to the forty-sixth pin of the power management chip. The fourth capacitor has one end grounded and the other end connected to the forty-fifth pin of the power management chip; the fifth capacitor has one end grounded and the other end connected to the fiftieth pin of the power management chip; the first pin of the crystal oscillator is connected to the fiftieth pin of the power management chip; the second pin of the crystal oscillator is connected to the fifty-first pin of the power management chip; and the third pin of the crystal oscillator is grounded. The sixth capacitor has one end grounded and the other end connected to the fifty-first pin of the power management chip; one end of the first resistor is connected to the sixty-eighth pin of the power management chip, and the other end is connected to the power supply VCC; the seventh capacitor has one end grounded and the other end connected to the sixty-seventh pin of the power management chip; one end of the second resistor is connected to the seventh capacitor, and the other end is connected to a 3V3 capacitor.3V voltage; pins 59 and 58 of the power management chip are connected in series; one end of the first inductor is electrically connected to pin 53 of the power management chip, and the other end is connected to the common terminal of pins 59 and 58 of the power management chip; one end of the eighth capacitor is grounded and the other end is electrically connected to the first inductor; one end of the ninth capacitor is grounded and the other end is electrically connected to the eighth capacitor; the common terminal of the eighth and ninth capacitors is connected to the device power system; one end of the third resistor is electrically connected to pin 60 of the power management chip, and the other end is electrically connected to pin 56 of the power management chip; pins 57 and 56 of the power management chip are electrically connected; the gate of the first MOSFET is electrically connected to the third resistor; the drain of the first MOSFET is electrically connected to the... The power management chip's 56th pin is electrically connected; the drain of the first MOSFET is electrically connected to the power management chip's 59th pin; one end of the 10th capacitor is grounded, and the other end is electrically connected to the drain of the first MOSFET; the power management chip's 61st pin is electrically connected to the rechargeable battery; one end of the 11th capacitor is electrically connected to the power management chip's 62nd pin, and the other end is electrically connected to the power management chip's 63rd pin; the fourth and fifth resistors are connected in series, one end of which is electrically connected to the power management chip's 62nd pin, and the other end is electrically connected to the power management chip's 63rd pin; the common terminal of the fourth and fifth resistors is grounded; the fifth resistor is electrically connected to the rechargeable battery; one end of the 12th capacitor is grounded, and the other end is electrically connected to the power management chip's 52nd pin.
[0008] Furthermore, the power management chip is model PMIC_RK817_5.
[0009] Furthermore, the small-capacity battery regulation and protection circuit also includes a boost circuit, which is electrically connected to the charge / discharge switching control circuit. The boost circuit includes a boost chip, a second inductor, a first diode, a thirteenth capacitor, a fourteenth capacitor, a fifteenth capacitor, a sixteenth capacitor, a seventeenth capacitor, an eighteenth capacitor, a nineteenth capacitor, a sixth resistor, a seventh resistor, an eighth resistor, and a ninth resistor. The thirteenth and fourteenth capacitors are connected in parallel, with one end grounded and the other end electrically connected to the sixth resistor. One end of the seventh resistor is electrically connected to the sixth resistor, and the other end is electrically connected to the thirteenth capacitor. The fourth pin of the boost chip is connected to the common terminal of the sixth and seventh resistors. An inductor, a first diode, an eighth resistor, and a ninth resistor are connected in series, with one end connected to the fifth pin of the boost chip and the other end connected to the thirteenth capacitor. The second pin of the boost chip is connected to the common terminal of the second inductor and the first diode. One end of the fifteenth capacitor is connected to the eighth resistor, and the other end is connected to the common terminal of the eighth and ninth resistors. The third pin of the boost chip is connected to the common terminal of the eighth and ninth resistors. The sixteenth and seventeenth capacitors are connected in parallel, with one end connected to the fifteenth capacitor and the other end connected to the ninth resistor. The eighteenth and nineteenth capacitors are connected in parallel, with one end grounded and the other end connected to the sixteenth capacitor.
[0010] Furthermore, the small-capacity battery regulation and protection circuit also includes a step-down circuit, which is electrically connected to the charge / discharge switching control circuit. The step-down circuit includes a step-down chip, a third inductor, a twentieth capacitor, a twenty-first capacitor, a twenty-second capacitor, a twenty-third capacitor, a twenty-fourth capacitor, a twenty-fifth capacitor, a tenth resistor, an eleventh resistor, a twelfth resistor, and a thirteenth resistor. The fifth pin of the step-down chip is electrically connected to the seventeenth capacitor. The twentieth and twenty-first capacitors are connected in parallel, one end of which is electrically connected to the seventeenth capacitor, and the other end is grounded. The tenth and eleventh resistors are connected in series, one end of which is connected to the twentieth capacitor, and the other end is connected to the thirteenth capacitor. The common terminal of capacitor 20 and capacitor 21; the fourth pin of the step-down chip is connected to the common terminal of resistors 10 and 11, and the second pin of the step-down chip is electrically connected to resistor 11; capacitor 22, inductor 3, resistor 12, and resistor 13 are connected in series, one end of which is electrically connected to pin 1 of the step-down chip, and the other end is grounded; one end of capacitor 23 is connected to resistor 12, and the other end is electrically connected to pin 3 of the step-down chip, and pin 6 of the step-down chip is electrically connected to capacitor 21; capacitors 24 and 25 are connected in parallel, one end of which is electrically connected to resistor 13, and the other end of which is electrically connected to capacitor 23.
[0011] Further; the charge / discharge switching control circuit includes a second diode, a twenty-sixth capacitor, a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, a seventeenth resistor, an eighteenth resistor, a nineteenth resistor, a second MOSFET, a third MOSFET, and a fourth MOSFET; the fourteenth resistor and the second diode are connected in series, one end of which is electrically connected to the nineteenth capacitor, and the other end is electrically connected to the source of the second MOSFET; the fifteenth resistor and the twenty-sixth capacitor are connected in series, one end of which is electrically connected to the second diode, and the other end is electrically connected to the fourteenth resistor; the common terminal of the fifteenth resistor and the twenty-sixth capacitor is grounded, and one end of the sixteenth resistor is connected to the source of the second diode. The gate of the second MOSFET is electrically connected, and the other end is electrically connected to the fourteenth resistor; the seventeenth and eighteenth resistors are connected in series, with one end grounded and the other end electrically connected to the drain of the second MOSFET; the gate of the third MOSFET is connected to the common terminal of the seventeenth and eighteenth resistors; the drain of the third MOSFET is connected to the eighteenth resistor; the source of the third MOSFET is electrically connected to the gate of the fourth MOSFET; one end of the nineteenth resistor is electrically connected to the source of the third MOSFET, and the other end is electrically connected to the source of the fourth MOSFET; the drain of the fourth MOSFET is connected to the device power supply system.
[0012] The beneficial effects of this utility model are:
[0013] This invention provides a small-capacity battery regulation and protection circuit. Through the cooperation of a power management integrated circuit, a CPU module, and a charge / discharge switching control circuit, it can monitor the battery status in real time and accurately, effectively preventing over-discharge and over-charge of the rechargeable battery. This solves the problem of battery bulging, extends the battery's lifespan, and significantly improves the safety performance of the device. This application not only optimizes battery management efficiency but also provides users with a more stable and reliable device experience. Furthermore, this application is not only simple in structure but also has low manufacturing costs. Attached Figure Description
[0014] Figure 1 This is a schematic diagram illustrating the working principle of a small-capacity battery regulation and protection circuit according to this utility model.
[0015] Figure 2 This is a circuit diagram of a power management integrated circuit in a small-capacity battery regulation and protection circuit according to this utility model.
[0016] Figure 3 This is a circuit diagram of the charge / discharge switching control circuit in a small-capacity battery regulation and protection circuit according to this utility model.
[0017] Figure 4 This is a circuit diagram of the boost circuit in a small-capacity battery regulation and protection circuit according to this utility model.
[0018] Figure 5 This is a circuit diagram of a step-down circuit in a small-capacity battery regulation and protection circuit according to this utility model. Detailed Implementation
[0019] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.
[0020] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in this utility model embodiment are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.
[0021] Furthermore, the use of terms such as "first" and "second" in this utility model is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this utility model.
[0022] This invention proposes a regulation and protection circuit for small-capacity batteries.
[0023] In the embodiments of this utility model, such as Figure 1-5 As shown, this small-capacity battery regulation and protection circuit provides protection for the rechargeable battery when it is connected to a charging device for charging. It includes a CPU module, a charge / discharge switching control circuit, and a power management integrated circuit. The power management integrated circuit is disposed between the charging device and the rechargeable battery. The output terminal of the charging device is electrically connected to the input terminal of the power management integrated circuit, and the input terminal of the rechargeable battery is electrically connected to the output terminal of the power management integrated circuit. The CPU module and the power management integrated circuit are connected via an I2C interface, and the charge / discharge switching control circuit is electrically connected to the charging device.
[0024] In this embodiment, the power management integrated circuit includes a power management chip, a crystal oscillator, a first inductor, a first MOSFET, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor, a sixth capacitor, a seventh capacitor, an eighth capacitor, a ninth capacitor, a tenth capacitor, an eleventh capacitor, a twelfth capacitor, a first resistor, a second resistor, a third resistor, a fourth resistor, and a fifth resistor; one end of the first capacitor is grounded, and the other end is electrically connected to the fifty-fourth pin of the power management chip; one end of the second capacitor is grounded, and the other end is electrically connected to the fifty-fifth pin of the power management chip; the sixty-ninth pin and the forty-seventh pin of the power management chip are connected in series, and the common terminal of the sixty-ninth pin and the forty-seventh pin of the power management chip is grounded; one end of the third capacitor is grounded, and the other end is connected to the fortyth pin of the power management chip. The system has six electrical connections: one end of the fourth capacitor is grounded, and the other end is connected to the forty-fifth pin of the power management chip; one end of the fifth capacitor is grounded, and the other end is connected to the fiftieth pin of the power management chip; the first pin of the crystal oscillator is connected to the fiftieth pin of the power management chip; the second pin of the crystal oscillator is connected to the fifty-first pin of the power management chip; and the third pin of the crystal oscillator is grounded. One end of the sixth capacitor is grounded, and the other end is connected to the fifty-first pin of the power management chip; one end of the first resistor is connected to the sixty-eighth pin of the power management chip, and the other end is connected to the power supply VCC; one end of the seventh capacitor is grounded, and the other end is connected to the sixty-seventh pin of the power management chip; one end of the second resistor is connected to the seventh capacitor, and the other end is connected to a 3V power supply.3V voltage; pins 59 and 58 of the power management chip are connected in series; one end of the first inductor is electrically connected to pin 53 of the power management chip, and the other end is connected to the common terminal of pins 59 and 58 of the power management chip; one end of the eighth capacitor is grounded and the other end is electrically connected to the first inductor; one end of the ninth capacitor is grounded and the other end is electrically connected to the eighth capacitor; the common terminal of the eighth and ninth capacitors is connected to the device power system; one end of the third resistor is electrically connected to pin 60 of the power management chip, and the other end is electrically connected to pin 56 of the power management chip; pins 57 and 56 of the power management chip are electrically connected; the gate of the first MOSFET is electrically connected to the third resistor; the drain of the first MOSFET is electrically connected to the... The power management chip's 56th pin is electrically connected; the drain of the first MOSFET is electrically connected to the power management chip's 59th pin; one end of the 10th capacitor is grounded, and the other end is electrically connected to the drain of the first MOSFET; the power management chip's 61st pin is electrically connected to the rechargeable battery; one end of the 11th capacitor is electrically connected to the power management chip's 62nd pin, and the other end is electrically connected to the power management chip's 63rd pin; the fourth and fifth resistors are connected in series, one end of which is electrically connected to the power management chip's 62nd pin, and the other end is electrically connected to the power management chip's 63rd pin; the common terminal of the fourth and fifth resistors is grounded; the fifth resistor is electrically connected to the rechargeable battery; one end of the 12th capacitor is grounded, and the other end is electrically connected to the power management chip's 52nd pin.
[0025] In this embodiment, the power management chip is model PMIC_RK817_5.
[0026] In this embodiment, the small-capacity battery regulation and protection circuit further includes a boost circuit, which is electrically connected to the charge / discharge switching control circuit. The boost circuit includes a boost chip, a second inductor, a first diode, a thirteenth capacitor, a fourteenth capacitor, a fifteenth capacitor, a sixteenth capacitor, a seventeenth capacitor, an eighteenth capacitor, a nineteenth capacitor, a sixth resistor, a seventh resistor, an eighth resistor, and a ninth resistor. The thirteenth and fourteenth capacitors are connected in parallel, with one end grounded and the other end electrically connected to the sixth resistor. One end of the seventh resistor is electrically connected to the sixth resistor, and the other end is electrically connected to the thirteenth capacitor. The fourth pin of the boost chip is connected to the common terminal of the sixth and seventh resistors. Two inductors, a first diode, an eighth resistor, and a ninth resistor are connected in series, with one end connected to the fifth pin of the boost chip and the other end connected to the thirteenth capacitor. The second pin of the boost chip is connected to the common terminal of the second inductor and the first diode. One end of the fifteenth capacitor is connected to the eighth resistor and the other end is connected to the common terminal of the eighth and ninth resistors. The third pin of the boost chip is connected to the common terminal of the eighth and ninth resistors. The sixteenth and seventeenth capacitors are connected in parallel, with one end connected to the fifteenth capacitor and the other end connected to the ninth resistor. The eighteenth and nineteenth capacitors are connected in parallel, with one end grounded and the other end connected to the sixteenth capacitor.
[0027] In this embodiment, the small-capacity battery regulation and protection circuit further includes a step-down circuit, which is electrically connected to the charge / discharge switching control circuit. The step-down circuit includes a step-down chip, a third inductor, a twentieth capacitor, a twenty-first capacitor, a twenty-second capacitor, a twenty-third capacitor, a twenty-fourth capacitor, a twenty-fifth capacitor, a tenth resistor, an eleventh resistor, a twelfth resistor, and a thirteenth resistor. The fifth pin of the step-down chip is electrically connected to the seventeenth capacitor. The twentieth and twenty-first capacitors are connected in parallel, one end of which is electrically connected to the seventeenth capacitor, and the other end is grounded. The tenth and eleventh resistors are connected in series, one end of which is connected to the twentieth capacitor, and the other end is connected to the... The common terminal of the 20th and 21st capacitors; the fourth pin of the step-down chip is connected to the common terminal of the 10th and 11th resistors, and the second pin of the step-down chip is electrically connected to the 11th resistor; the 22nd capacitor, the third inductor, the 12th resistor, and the 13th resistor are connected in series, with one end electrically connected to the first pin of the step-down chip and the other end grounded; one end of the 23rd capacitor is connected to the 12th resistor and the other end is electrically connected to the third pin of the step-down chip, and the sixth pin of the step-down chip is electrically connected to the 21st capacitor; the 24th and 25th capacitors are connected in parallel, with one end electrically connected to the 13th resistor and the other end electrically connected to the 23rd capacitor.
[0028] In this embodiment, the charge / discharge switching control circuit includes a second diode, a twenty-sixth capacitor, a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, a seventeenth resistor, an eighteenth resistor, a nineteenth resistor, a second MOSFET, a third MOSFET, and a fourth MOSFET. The fourteenth resistor and the second diode are connected in series, with one end electrically connected to the nineteenth capacitor and the other end electrically connected to the source of the second MOSFET. The fifteenth resistor and the twenty-sixth capacitor are connected in series, with one end electrically connected to the second diode and the other end electrically connected to the fourteenth resistor. The common terminal of the fifteenth resistor and the twenty-sixth capacitor is grounded, and one end of the sixteenth resistor is connected to... The gate of the second MOS transistor is electrically connected, and the other end is electrically connected to the fourteenth resistor; the seventeenth and eighteenth resistors are connected in series, with one end grounded and the other end electrically connected to the drain of the second MOS transistor; the gate of the third MOS transistor is connected to the common terminal of the seventeenth and eighteenth resistors; the drain of the third MOS transistor is connected to the eighteenth resistor; the source of the third MOS transistor is electrically connected to the gate of the fourth MOS transistor; one end of the nineteenth resistor is electrically connected to the source of the third MOS transistor, and the other end is electrically connected to the source of the fourth MOS transistor; the drain of the fourth MOS transistor is connected to the device power supply system.
[0029] The CPU module communicates with the power management integrated circuit via an I2C interface to obtain the rechargeable battery power and charging / discharging status. This application can be used in portable devices, such as tablets.
[0030] When charging, the rechargeable battery is charged via an external charging device, which can be an external adapter. The external adapter connects to the power management integrated circuit (IC), and the CPU module reads the battery's charge level from the registers in the IC via the I2C interface to determine whether to continue charging. At this time, the external adapter supplies power to the IC and charges the battery, while also supplying power to the device's power system.
[0031] When charging is stopped, the CPU module reads the battery level from the registers in the power management integrated circuit via the I2C interface and determines that the battery is fully charged, then controls the power management integrated circuit to stop charging. At this time, the power management integrated circuit disconnects the battery, and the external adapter supplies power to the power management integrated circuit only to power the device's power system.
[0032] When in a discharge state, the CPU module determines the discharge cycle and disconnects the input of the external adapter. At this time, the rechargeable battery supplies power to the device's power system and power management integrated circuit, thereby initiating the discharge process.
[0033] When switching from charging to discharging, the rechargeable battery has been disconnected. Disconnecting the external adapter input at this time will cause the device's power system to shut down abnormally due to lack of power. After detecting that the external adapter is disconnected, the rechargeable battery is immediately connected to the device's power system to ensure that the device's power system is powered normally.
[0034] When powered by an external adapter, the 25th capacitor C5210 is charged through the third diode D1207. After the external adapter is disconnected, the 25th capacitor C5210 can only discharge through the second MOSFET Q4801 due to the reverse cutoff of the second diode D1207. The source of the second MOSFET Q4801 is powered by the second MOSFET Q4801. The source of the second MOSFET Q4801 is de-energized very slowly, while the gate is de-energized very quickly. Thus, after the power is lost, VGS can immediately reach the turn-on voltage, turning on the second MOSFET Q4801, which in turn turns on the fourth MOSFET Q603. This allows the power supply to switch to the rechargeable battery immediately after the external power supply is lost, preventing the device's power system from shutting down.
[0035] This application addresses the over-discharge and overcharge issues present in the rechargeable battery management of portable devices with small-capacity batteries currently on the market. Through the collaboration of a power management integrated circuit, a CPU module, and a charge / discharge switching control circuit, it enables real-time and accurate monitoring of battery status, effectively preventing over-discharge and overcharge, thus resolving the battery bulging problem, extending battery life, and significantly improving device safety. This application not only optimizes battery management efficiency but also provides users with a more stable and reliable device experience.
[0036] This application enables real-time and accurate monitoring of battery status, effectively preventing battery bulging caused by over-discharge and overcharge, thereby extending battery life and reducing user maintenance costs. Simultaneously, this application enhances device safety performance, avoiding potential safety hazards caused by improper battery management, such as short circuits and overheating, thus improving the user experience.
[0037] The above description is only a preferred embodiment of the present utility model and does not limit the patent scope of the present utility model. All equivalent structural transformations made under the inventive concept of the present utility model using the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present utility model.
Claims
1. A small capacity battery regulating protection circuit for providing protection to a rechargeable battery when the rechargeable battery is connected to a charging device for charging, characterized in that, The small-capacity battery adjusting protection circuit comprises a CPU module, a charge-discharge switching control circuit and a power management integrated circuit; the power management integrated circuit is arranged between the charging device and the charging battery, the output end of the charging device is electrically connected with the input end of the power management integrated circuit, and the input end of the charging battery is electrically connected with the output end of the power management integrated circuit; the CPU module and the power management integrated circuit are in communication connection through an I2C interface, and the charge-discharge switching control circuit is electrically connected with the charging device. 2. The small battery regulating protection circuit according to claim 1, wherein The power management integrated circuit includes a power management chip, a crystal oscillator, a first inductor, a first MOS tube, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor, a sixth capacitor, a seventh capacitor, an eighth capacitor, a ninth capacitor, a tenth capacitor, an eleventh capacitor, a twelfth capacitor, a first resistor, a second resistor, a third resistor, a fourth resistor and a fifth resistor; one end of the first capacitor is grounded, and the other end is connected with the fifty-fourth pin of the power management chip; one end of the second capacitor is grounded, and the other end is connected with the fifty-fifth pin of the power management chip; the sixty-ninth pin and the forty-seventh pin of the power management chip are connected in series, and the common end of the sixty-ninth pin and the forty-seventh pin of the power management chip is grounded; one end of the third capacitor is grounded, and the other end is connected with the forty-sixth pin of the power management chip; one end of the fourth capacitor is grounded, and the other end is connected with the forty-fifth pin of the power management chip; one end of the fifth capacitor is grounded, and the other end is connected with the fiftieth pin of the power management chip; the first pin of the crystal oscillator is connected with the fiftieth pin of the power management chip, the second pin of the crystal oscillator is connected with the fifty-first pin of the power management chip, and the third pin of the crystal oscillator is grounded; one end of the sixth capacitor is grounded, and the other end is connected with the fifty-first pin of the power management chip; one end of the first resistor is connected with the sixty-eighth pin of the power management chip, and the other end is connected with a power supply VCC; one end of the seventh capacitor is grounded, and the other end is connected with the sixty-seventh pin of the power management chip; one end of the second resistor is connected with the seventh capacitor, and the other end is connected with 3.3V voltage; the 59th pin and the 58th pin of the power management chip are connected in series, one end of the first inductor is electrically connected to the 53rd pin of the power management chip, and the other end is connected to the common end of the 59th pin and the 58th pin of the power management chip; one end of the eighth capacitor is grounded, and the other end is electrically connected to the first inductor; one end of the ninth capacitor is grounded, and the other end is electrically connected to the eighth capacitor; the common end of the eighth capacitor and the ninth capacitor is connected with a device end power supply system; one end of the third resistor is electrically connected to the 60th pin of the power management chip, and the other end is electrically connected to the 56th pin of the power management chip; the 57th pin of the power management chip is electrically connected to the 56th pin of the power management chip; the gate of the first MOS tube is electrically connected to the third resistor; the drain of the first MOS tube is electrically connected to the 56th pin of the power management chip; the drain of the first MOS tube is electrically connected to the 59th pin of the power management chip; one end of the tenth capacitor is grounded, and the other end is electrically connected to the drain of the first MOS tube; the 61st pin of the power management chip is electrically connected to the charging battery; one end of the eleventh capacitor is electrically connected to the 62nd pin of the power management chip, and the other end is electrically connected to the 63rd pin of the power management chip; the fourth resistor and the fifth resistor are connected in series, one end is electrically connected to the 62nd pin of the power management chip, and the other end is electrically connected to the 63rd pin of the power management chip; the common end of the fourth resistor and the fifth resistor is grounded; the fifth resistor is electrically connected to the charging battery; one end of the twelfth capacitor is grounded, and the other end is electrically connected to the 52nd pin of the power management chip.
3. The small battery regulating protection circuit according to claim 2, wherein The power management chip model is PMIC_RK817_5.
4. The small battery regulating protection circuit according to claim 1, wherein The small-capacity battery adjusting protection circuit further comprises a boost circuit, which is electrically connected with the charge-discharge switching control circuit; the boost circuit comprises a boost chip, a second inductor, a first diode, a thirteenth capacitor, a fourteenth capacitor, a fifteenth capacitor, a sixteenth capacitor, a seventeenth capacitor, an eighteenth capacitor, a nineteenth capacitor, a sixth resistor, a seventh resistor, an eighth resistor and a ninth resistor; the thirteenth capacitor and the fourteenth capacitor are in parallel connection, one end of which is grounded, and the other end of which is electrically connected with the sixth resistor; one end of the seventh resistor is electrically connected with the sixth resistor, and the other end of the seventh resistor is electrically connected with the thirteenth capacitor; the fourth pin of the boost chip is connected to the common end of the sixth resistor and the seventh resistor; the second inductor, the first diode, the eighth resistor and the ninth resistor are in series connection, one end of which is connected to the fifth pin of the boost chip, and the other end of which is electrically connected with the thirteenth capacitor; the second pin of the boost chip is connected to the common end of the second inductor and the first diode; one end of the fifteenth capacitor is electrically connected with the eighth resistor, and the other end of the fifteenth capacitor is connected to the common end of the eighth resistor and the ninth resistor; the third pin of the boost chip is connected to the common end of the eighth resistor and the ninth resistor; the sixteenth capacitor and the seventeenth capacitor are in parallel connection, one end of which is connected to the fifteenth capacitor, and the other end of which is connected to the ninth resistor; the eighteenth capacitor and the nineteenth capacitor are in parallel connection, one end of which is grounded, and the other end of which is electrically connected with the sixteenth capacitor.
5. The small battery regulating protection circuit according to claim 4, wherein The small capacity battery adjustment protection circuit further comprises a voltage reduction circuit electrically connected with the charge-discharge switching control circuit; the voltage reduction circuit comprises a voltage reduction chip, a third inductor, a twentieth capacitor, a twenty-first capacitor, a twenty-second capacitor, a twenty-third capacitor, a twenty-fourth capacitor, a twenty-fifth capacitor, a tenth resistor, an eleventh resistor, a twelfth resistor and a thirteenth resistor; a fifth pin of the voltage reduction chip is electrically connected with the seventeenth capacitor; the twentieth capacitor and the twenty-first capacitor are both in parallel, one end of which is electrically connected with the seventeenth capacitor, and the other end of which is grounded; the tenth resistor and the eleventh resistor are both in series, one end of which is connected to the twentieth capacitor, and the other end of which is connected to a common end of the twentieth capacitor and the twenty-first capacitor; a fourth pin of the voltage reduction chip is connected to the common end of the tenth resistor and the eleventh resistor, and a second pin of the voltage reduction chip is electrically connected with the eleventh resistor; the twenty-second capacitor, the third inductor, the twelfth resistor and the thirteenth resistor are in series, one end of which is electrically connected with a first pin of the voltage reduction chip, and the other end of which is grounded; one end of the twenty-third capacitor is connected to the twelfth resistor, and the other end of the twenty-third capacitor is electrically connected with a third pin of the voltage reduction chip; a sixth pin of the voltage reduction chip is electrically connected with the twenty-first capacitor; the twenty-fourth capacitor and the twenty-fifth capacitor are both in parallel, one end of which is electrically connected with the thirteenth resistor, and the other end of which is electrically connected with the twenty-third capacitor.
6. The small battery regulating protection circuit according to claim 5, wherein The charge-discharge switching control circuit comprises a second diode, a twenty-sixth capacitor, a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, a seventeenth resistor, an eighteenth resistor, a nineteenth resistor, a second MOS tube, a third MOS tube and a fourth MOS tube; the fourteenth resistor and the second diode are both in series, one end of which is electrically connected with the nineteenth capacitor, and the other end of which is electrically connected with a source electrode of the second MOS tube; the fifteenth resistor and the twenty-sixth capacitor are both in series, one end of which is electrically connected with the second diode, and the other end of which is electrically connected with the fourteenth resistor; a common end of the fifteenth resistor and the twenty-sixth capacitor is grounded; one end of the sixteenth resistor is electrically connected with a gate electrode of the second MOS tube, and the other end of the sixteenth resistor is electrically connected with the fourteenth resistor; the seventeenth resistor and the eighteenth resistor are both in series, one end of which is grounded, and the other end of which is electrically connected with a drain electrode of the second MOS tube; a gate electrode of the third MOS tube is connected to a common end of the seventeenth resistor and the eighteenth resistor; a drain electrode of the third MOS tube is connected to the eighteenth resistor; a source electrode of the third MOS tube is electrically connected with a gate electrode of the fourth MOS tube; one end of the nineteenth resistor is electrically connected with a source electrode of the third MOS tube, and the other end of the nineteenth resistor is electrically connected with a source electrode of the fourth MOS tube; a drain electrode of the fourth MOS tube is connected with a device end power supply system.