Battery charging constant-current constant-voltage circuit

Abstract

The utility model discloses a battery charging constant-current constant-voltage circuit, which comprises a power interface, a constant-current circuit, a constant-voltage circuit and a battery pack, the power interface is used for being externally connected with a power supply; the constant current circuit is connected to the power interface and is used for limiting input current of an external power supply; the constant voltage circuit is connected to the constant current circuit and is used for stabilizing the output voltage and stabilizing the voltage within a rechargeable range of the battery pack; the battery pack is connected to the constant voltage circuit, is used for storing electric energy and carrying out charging and discharging management, and comprises a charging management circuit, a battery protection circuit and an electric quantity detection circuit. According to the scheme of the utility model, the thought that the current is set by the battery chip and the voltage is set by the voltage stabilizing source is ingeniously utilized, the power from the input source to the battery pack is effectively controlled, and a simple, applicable, reliable and flexible scheme is provided for application scenes in which small-power power supplies supply power to a system and continuously charge the system.

Description

Technical Field

[0001] The utility model relates to the technical field of battery charging, in particular to a battery charging constant current and constant voltage circuit. Background Art

[0002] Existing battery charging technologies often encounter challenges, particularly when a low-power power source is required to charge a higher-power battery. Using an underpowered adapter in such applications can result in the power source failing to provide sufficient charging current to the battery, preventing effective charging. This insufficiency can also impact other parts of the system, causing the entire system to malfunction. This is particularly common when using unstable power sources such as AC power, solar panels, or low-power adapters. These sources may not provide stable voltage and sufficient current, limiting battery charging efficiency and overall system performance.

[0003] Furthermore, battery charging packs typically have a specific charging current range (usually between 500mA and 2A) and built-in safety features such as charge and discharge protection, temperature detection, and battery count statistics. While these features are crucial to battery safety and efficiency, they may not function adequately in the face of unstable or insufficient power supplies, and may even cause the power supply to freeze, preventing the backend system from receiving the necessary power supply.

[0004] Therefore, existing battery charging solutions have obvious limitations when dealing with unstable power sources or low-power adapters. This not only affects the efficiency of battery charging, but also limits the stability and reliability of the system. This requires an innovative solution that can provide stable and safe charging for battery packs under different power conditions while ensuring effective system operation. Utility Model Content

[0005] In view of the problems existing in the prior art, the utility model provides a battery charging constant current and constant voltage circuit.

[0006] In order to achieve the above object, the utility model provides a battery charging constant current and constant voltage circuit, including a power interface, a constant current circuit, a constant voltage circuit, and a battery pack;

[0007] The power interface is used for external power supply;

[0008] The constant current circuit is connected to the power interface and is used to limit the input current of the external power supply;

[0009] The constant voltage circuit is connected to the constant current circuit to stabilize the output voltage and keep the voltage within the chargeable range of the battery pack;

[0010] The battery pack is connected to a constant voltage circuit for storing electrical energy and performing charge and discharge management. The battery pack includes a charging management circuit, a battery protection circuit, and a power detection circuit. The corresponding ends of the charging management circuit are electrically connected to the corresponding ends of the battery protection circuit and the power detection circuit, respectively.

[0011] Preferably, the external power supply includes an AC power supply, a high-voltage DC power supply, a low-voltage DC power supply, or a solar panel.

[0012] Preferably, the constant current circuit includes a boost charging chip U2, a capacitor C22, a capacitor C23, a capacitor C24, a capacitor C25, a capacitor C26, a resistor R34, a resistor R35, a resistor R36, a resistor R37, an inductor L4, a diode D9, and a MOS tube Q6; the first pin of the boost charging chip U2 is electrically connected to the first end of the inductor L4, the resistor R34, and the capacitor C22, respectively, the second pin of the boost charging chip U2 is electrically connected to the first end of the resistor R37 and the capacitor C26, and the second end of the capacitor C26 is grounded; the third pin of the boost charging chip U2 is electrically connected to the second end of the inductor L4 and the first end of the diode D9, respectively, and the fourth pin of the boost charging chip U2 is electrically connected to the second end of the resistor R37. Electrically connected, the 5th pin of the boost charging chip U2 is electrically connected to the second end of the resistor R34 and the first end of the resistor R35, respectively, the 6th pin of the boost charging chip U2 is electrically connected to the source of the MOSFET Q6 and the first end of the resistor R36, respectively, the 7th pin of the boost charging chip U2 is electrically connected to the second end of the resistor R36, the corresponding end of the constant voltage circuit, and the first end of the capacitor C25, and the second end of the capacitor C25 is grounded; the 8th pin of the boost charging chip U2 is electrically connected to the gate of the MOSFET Q6 and the first end of the capacitor C24, respectively, and the second end of the capacitor C24 is grounded; the second end of the diode D9 is electrically connected to the first end of the capacitor C23 and the drain of the MOSFET Q6, respectively, and the second end of the capacitor C23 is grounded.

[0013] Preferably, the model of the boost charging chip U2 is LP28400ASPF.

[0014] Preferably, the constant voltage circuit includes a power supply chip U20, a capacitor C20, a capacitor C21, and a capacitor C36; the first pin of the power supply chip U20 is electrically connected to the first ends of the capacitors C21, C20, and C36 and is grounded, the second pin of the power supply chip U20 is electrically connected to the seventh pin of the voltage charging chip U2, the capacitor C20, and the second end of the capacitor C36, and the third pin of the power supply chip U20 is electrically connected to the second end of the capacitor C21.

[0015] Preferably, the model of the power chip U20 is SE8650.

[0016] Preferably, the charge management circuit comprises a synchronous step-down charging chip U6 and its peripheral circuit, a TYPE-C interface, the corresponding end of the synchronous step-down charging chip U6 is electrically connected with the corresponding end of the TYPE-C interface, and the model of the synchronous step-down charging chip U6 is IU5987T.

[0017] Preferably, the battery protection circuit comprises a battery protection chip U3, an MXN3380 chip U2, a thermistor R12, a resistor R13, a resistor R14, a capacitor C7, a capacitor C8, a capacitor C9, a capacitor C10, a capacitor C11, a capacitor C12 and a capacitor C13, the first pin and the fourth pin of the battery protection chip U3 are connected with the fifth pin and the fourth pin of the MXN3380 chip U2, the second pin of the battery protection chip U3 is electrically connected with the first pin, the second pin and the third pin of the MXN3380 chip U2, the first end of the capacitor C13 and the first end of the capacitor C11 respectively through the resistor R14, the fifth pin of the battery protection chip U3 is electrically connected with the first end of the resistor R13 and the first end of the capacitor C8 respectively, the second end of the resistor R13 is electrically connected with the first end of the thermistor R12 and the first end of the capacitor C7 respectively, the second end of the capacitor C7 is electrically connected with the second end of the capacitor C11, the second end of the capacitor C13 is electrically connected with the eighth pin, the seventh pin and the sixth pin of the MXN3380 chip U2, the sixth pin of the battery protection chip U3, the second end of the capacitor C8, the first end of the capacitor C9 and the first end of the capacitor C10 respectively through the capacitor C12, and the second end of the thermistor R12 is electrically connected with the second end of the capacitor C9 and the second end of the capacitor C10 respectively.

[0018] Preferably, the model of the battery protection chip U3 is R5478N218CD.

[0019] Preferably, the power detection circuit comprises a battery power gauge chip U1 and its peripheral circuit, and the model of the battery power gauge chip U1 is CW2017AAAD.

[0020] In order to achieve the above-mentioned purposes, the technical scheme of the utility model is as follows:

[0021] The technical scheme of the utility model has the following beneficial effects:

[0022] The utility model discloses a cleverly use the current of battery chip setting, the thought of voltage setting of voltage regulator, will effectively control the power of input source to battery package. In this case, in some low -power power supply both want to power system, and want to provide simple, applicable, reliable, flexible scheme for the application scene of continuous charging. Only need to change different chip, set up different current, voltage can satisfy many this scene's use.

[0023] The utility model discloses a battery charging package is connected with external power supply through power interface, and the power supply can be AC power supply, high -voltage DC power supply, low -voltage DC power supply or solar panel.

[0024] Constant current circuit: when power supply is connected, constant current circuit starts to work, limits the current input from power interface, prevents the front end power supply from hanging when power supply is insufficient, limits the current of the front end into battery package loop in the use range through current limiting function, and promotes input voltage to the voltage level suitable for battery charging.

[0025] Constant voltage circuit: constant voltage circuit ensures that voltage is stabilized in the range that battery can be charged under the condition that the front end power supply voltage is unstable, and ensures that battery package obtains stable charging voltage.

[0026] Battery package charging management: the charging management circuit, battery protection circuit and electric quantity detection circuit in battery package work cooperatively, ensure that battery charges safely and efficiently;Charging management circuit is responsible for reducing input voltage to the charging voltage required by battery, and controls charging current to prevent battery overcharging;Battery protection circuit provides overcharge, overdischarge, short circuit protection function, and ensures safe operation of battery;Battery capacity meter chip is responsible for monitoring the remaining capacity of battery, provides high-precision electric quantity information, and helps user to understand battery state. In the charging process, constant voltage circuit can also provide stable power supply for the rear system, and ensure the effective operation of the system. Through battery protection circuit, temperature monitoring can be carried out: hot, temperature protection is provided, battery is prevented from working in overheating or overcooling environment, overtemperature monitoring and protection function, and the scheme ensures that battery can work safely under various environmental conditions, and enhances the environmental adaptability of battery. ACCURACY

[0027] Figure 1 It is control block diagram of the utility model;

[0028] Figure 2 It is circuit principle diagram of constant current circuit of the utility model;

[0029] Figure 3 It is circuit principle diagram of constant voltage circuit of the utility model;

[0030] Figure 4 It is circuit principle diagram of charging management circuit of the utility model;

[0031] Figure 5 This is a circuit diagram of the battery protection circuit of the utility model;

[0032] Figure 6 This is the circuit principle diagram of the power detection circuit of the utility model. DETAILED DESCRIPTION

[0033] The following describes in detail embodiments of the present invention, examples of which 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 intended to explain the present invention, and should not be construed as limiting the present invention.

[0034] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0035] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of such features. In the description of this utility model, "plurality" means two or more, unless otherwise specifically defined.

[0036] In this utility model, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integral connection; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on specific circumstances.

[0037] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Moreover, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0038] Reference Figures 1 to 6 The present invention provides a battery charging constant current and constant voltage circuit, comprising a power interface 100, a constant current circuit 200, a constant voltage circuit 300, and a battery pack 400;

[0039] The power interface 100 is used for connecting to an external power source, and can be connected to an AC power source, a high-voltage DC power source, a low-voltage DC power source, or a solar panel, ensuring that the circuit can obtain power from a variety of power sources, thereby improving the applicability and flexibility of the circuit;

[0040] The constant current circuit 200 is connected to the power interface and is used to limit the input current of the external power supply to prevent the front-end power supply from being hung up when the front-end power supply is insufficient; it ensures that the circuit operates stably under the condition of limited input current and provides a stable charging current for the battery pack;

[0041] The constant voltage circuit 200 is connected to the constant current circuit 200 and is used to stabilize the output voltage and keep the voltage within the chargeable range of the battery pack; protect the battery from voltage fluctuations and ensure safe and efficient charging of the battery;

[0042] The battery pack 400 is connected to the constant voltage circuit 300 and is used to store electrical energy and manage charge and discharge. The battery pack 400 includes a charging management circuit 401, a battery protection circuit 402, and a power detection circuit 403; the corresponding ends of the charging management circuit 401 are electrically connected to the corresponding ends of the battery protection circuit 402 and the power detection circuit 403, respectively, to ensure safe and efficient charging and discharging of the battery, while providing battery status monitoring and protection.

[0043] Further, the constant current circuit 200 comprises a boost charging chip U2, a capacitor C22, a capacitor C23, a capacitor C24, a capacitor C25, a capacitor C26, a resistor R34, a resistor R35, a resistor R36, a resistor R37, an inductor L4, a diode D9, and a mos tube Q6; a first pin of the boost charging chip U2 is electrically connected with the inductor L4, the resistor R34, and a first end of the capacitor C22 respectively, a second pin of the boost charging chip U2 is electrically connected with the resistor R37 and a first end of the capacitor C26 respectively, a second end of the capacitor C26 is grounded; a third pin of the boost charging chip U2 is electrically connected with a second end of the inductor L4 and a first end of the diode D9 respectively, a fourth pin of the boost charging chip U2 is electrically connected with a second end of the resistor R37 respectively, a fifth pin of the boost charging chip U2 is electrically connected with a second end of the resistor R34 and a first end of the resistor R35 respectively, a sixth pin of the boost charging chip U2 is electrically connected with a source of the mos tube Q6 and a first end of the resistor R36 respectively, a seventh pin of the boost charging chip U2 is electrically connected with a second end of the resistor R36, a corresponding end of the constant voltage circuit, and a first end of the capacitor C25 respectively, a second end of the capacitor C25 is grounded; an eighth pin of the boost charging chip U2 is electrically connected with a gate of the mos tube Q6 and a first end of the capacitor C24 respectively, a second end of the capacitor C24 is grounded; a second end of the diode D9 is electrically connected with a first end of the capacitor C23 and a drain of the mos tube Q6 respectively, and a second end of the capacitor C23 is grounded. In the embodiment, the design mainly comprises the U2 (model LP28400ASPF) and the peripheral circuit to form the entire constant current circuit. The design uses the current limiting function of the boost charging chip U2 to limit the current entering the battery pack loop within the use range, and the input voltage is too high.

[0044] The boost charging chip U2 used in the design supports an input voltage of 3V-12V, the power supply of the previous stage is set to 4.8V, the circuit passes through the inductor L4, the diode D9, the mos tube Q6, and the PB pin (eighth pin) of the chip to boost the output power supply to 6.2V-8.4V. In order to guarantee the stability of the entire pass, the capacitor size of the G level end of Q6 is adjusted to make the power supply stable output 6.2V power supply. According to Iset=5mV / R36, the output current is set, the larger the value of R36 is, the smaller the current will be, for example, 0.12Ω is adopted in the design, and the current is 41.7mA. If you want to adjust the current size, you only need to increase or decrease the resistance value, if you want to adjust the output voltage size, you need to adjust the capacitor of the mos tube to change the frequency.

[0045] Furthermore, the constant voltage circuit 300 includes a power chip U20, a capacitor C20, a capacitor C21, and a capacitor C36; the first pin of the power chip U20 is electrically connected to the first ends of the capacitors C21, C20, and C36 and is grounded, the second pin of the power chip U20 is electrically connected to the seventh pin of the pressure charging chip U2, the second end of the capacitor C20, and the capacitor C36, and the third pin of the power chip U20 is electrically connected to the second end of the capacitor C21. In this solution, U20 adopts a high-voltage to low-voltage circuit composed of a SE8650 power chip (this part of the power supply). The purpose of using this circuit is to isolate the voltage instability problem caused by the charging chip supplying power to the charging chip. This part can use an LDO circuit or a DC-DC circuit, depending on the design and use scenario. The voltage design can be set according to the input voltage range of the battery pack.

[0046] Furthermore, the charging management circuit 401 includes a synchronous buck charging chip U6 and its peripheral circuits, and a TYPE-C interface; the corresponding end of the synchronous buck charging chip U6 is electrically connected to the corresponding end of the TYPE-C interface; the model of the synchronous buck charging chip U6 is IU5987T; in this embodiment, the synchronous buck charging chip U6 (model IU5987T): manages the battery charging process to ensure safe charging of the battery. The synchronous buck charging chip U6 is responsible for reducing the input voltage to the charging voltage required by the battery and controlling the charging current to prevent the battery from overcharging; improving the charging efficiency, while protecting the battery from overcharging and over-discharging, and extending the battery life. The synchronous buck charging chip U6 is electrically connected to the TYPE-C interface, responsible for reducing the input voltage to the charging voltage required by the battery and controlling the charging current; ensuring that the battery pack can receive the appropriate charging voltage and current from the TYPE-C interface, improving the stability and efficiency of charging. TYPE-C interface: As an interface for power supply and data transmission, it allows users to charge the device or battery pack through a TYPE-C cable, providing a convenient charging method while supporting data transmission, enhancing the versatility and portability of the device.

[0047] Further, the battery protection circuit 402 comprises a battery protection chip U3, an MXN3380 chip U2, a thermistor R12, a resistor R13, a resistor R14, a capacitor C7, a capacitor C8, a capacitor C9, a capacitor C10, a capacitor C11, a capacitor C12, a capacitor C13; the first pin and the fourth pin of the battery protection chip U3 are connected with the fifth pin and the fourth pin of the MXN3380 chip U2, the second pin of the battery protection chip U3 is respectively electrically connected with the first pin of the MXN3380 chip U2, the second pin of the MXN3380 chip U2, the third pin of the MXN3380 chip U2, the first end of the capacitor C13 and the first end of the capacitor C11 through the resistor R14; the fifth pin of the battery protection chip U3 is respectively electrically connected with the first end of the resistor R13 and the first end of the capacitor C8; the second end of the resistor R13 is respectively electrically connected with the first end of the thermistor R12 and the first end of the capacitor C7; the second end of the capacitor C7 is electrically connected with the second end of the capacitor C11; the second end of the capacitor C13 is respectively electrically connected with the eighth pin of the MXN3380 chip U2, the seventh pin of the MXN3380 chip U2, the sixth pin of the MXN3380 chip U2, the sixth pin of the battery protection chip U3, the second end of the capacitor C8, the first end of the capacitor C9 and the first end of the capacitor C10 through the capacitor C12; the second end of the thermistor R12 is respectively electrically connected with the second end of the capacitor C9 and the second end of the capacitor C10; the model of the battery protection chip U3 is R5478N218CD; in the embodiment, the battery protection chip U3 monitors the state of the battery, provides overcharge, overdischarge, short circuit and other protection functions, ensures the safe operation of the battery, prevents the battery from being damaged under abnormal conditions, and prolongs the service life of the battery; the resistors R13 and R14 limit the current and divide the voltage, adjust the working state of the circuit, protect the circuit from being damaged by excessive current, accurately control the current, and ensure the stability of the circuit and the safe charging of the battery. The capacitors C7, C8, C9, C10, C11, C12 and C13 filter and store energy, stabilize the voltage fluctuation in the circuit, and provide transient response. The thermistor R12 detects the temperature of the battery, provides temperature protection, and prevents the battery from working in an overheated or overcooled environment. It ensures that the battery works in a safe temperature range and avoids damage caused by abnormal temperature.

[0048] Furthermore, the power detection circuit 403 includes a battery power meter chip U1 and its peripheral circuits, and the model of the battery power meter chip U1 is CW2017AAAD; the CW2017AAAD chip can accurately calculate the remaining power of the battery, provide high-precision power information, and help users understand the battery status; through precise power monitoring, users can better manage battery usage, avoid overcharging and over-discharging, thereby extending the battery life; the battery power meter chip U1 can monitor the health of the battery, detect battery problems in a timely manner, and improve the overall reliability of the device.

[0049] This innovative solution cleverly utilizes the battery chip to set the current and the voltage regulator to set the voltage, effectively controlling the power input to the battery pack. This provides a simple, applicable, reliable, and flexible solution for applications where a low-power source must both power the system and maintain continuous charging. Simply replacing the chip and setting different current and voltage settings can meet many such requirements.

[0050] The battery charging pack of the present invention is connected to an external power source through a power interface, and the power source can be an AC power source, a high-voltage DC power source, a low-voltage DC power source or a solar panel.

[0051] Constant current circuit: When the power supply is connected, the constant current circuit starts to work, limiting the current input from the power interface to prevent the front-end power supply from hanging due to insufficient power supply. The current limiting function limits the current entering the battery pack circuit from the front end to within the usable range and increases the input voltage to a voltage level suitable for battery charging.

[0052] Constant voltage circuit: The constant voltage circuit ensures that when the front-end power supply voltage is unstable, the voltage is stabilized within the battery's rechargeable range, ensuring that the battery pack obtains a stable charging voltage.

[0053] Battery pack charging management: The charging management circuit, battery protection circuit and power detection circuit inside the battery pack work together to ensure safe and efficient charging of the battery.

[0054] The charging management circuit is responsible for reducing the input voltage to the battery's required charging voltage and controlling the charging current to prevent overcharging. The battery protection circuit provides protection against overcharging, over-discharging, and short-circuiting to ensure safe battery operation. The battery fuel gauge chip monitors the remaining battery charge and provides highly accurate power information to help users understand the battery status. During the charging process, the constant voltage circuit also provides a stable power supply to downstream systems, ensuring efficient system operation. The battery protection circuit also monitors temperature, providing thermal protection to prevent the battery from operating in overheated or overcooled environments. This solution ensures safe battery operation in a variety of environmental conditions, enhancing the battery's environmental adaptability.

[0055] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. All equivalent structural transformations made by using the contents of the present invention specification and drawings under the utility model concept, or direct / indirect application in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A battery charging constant current and constant voltage circuit, characterized in that: Including power interface, constant current circuit, constant voltage circuit, and battery pack; The power interface is used for external power supply; The constant current circuit is connected to the power interface and is used to limit the input current of the external power supply; The constant voltage circuit is connected to the constant current circuit to stabilize the output voltage and keep the voltage within the chargeable range of the battery pack; The battery pack is connected to a constant voltage circuit for storing electrical energy and performing charge and discharge management. The battery pack includes a charge management circuit, a battery protection circuit, and a power detection circuit. The corresponding ends of the charging management circuit are electrically connected to the corresponding ends of the battery protection circuit and the power detection circuit respectively.

2. The battery charging constant current and constant voltage circuit according to claim 1, characterized in that: The external power supply includes an AC power supply, a high-voltage DC power supply, a low-voltage DC power supply, and a solar panel.

3. The battery charging constant current and constant voltage circuit according to claim 1, characterized in that: The constant current circuit includes a boost charging chip U2, capacitor C22, capacitor C23, capacitor C24, capacitor C25, capacitor C26, resistor R34, resistor R35, resistor R36, resistor R37, inductor L4, diode D9, and MOSFET Q6; the first pin of the boost charging chip U2 is electrically connected to the first end of the inductor L4, resistor R34, and capacitor C22 respectively, the second pin of the boost charging chip U2 is electrically connected to the first end of the resistor R37 and capacitor C26 respectively, and the second end of the capacitor C26 is grounded; the third pin of the boost charging chip U2 is electrically connected to the second end of the inductor L4 and the first end of the diode D9 respectively, and the fourth pin of the boost charging chip U2 is electrically connected to the second end of the resistor R37 respectively. The 5th pin of the boost charging chip U2 is electrically connected to the second end of the resistor R34 and the first end of the resistor R35, respectively. The 6th pin of the boost charging chip U2 is electrically connected to the source of the MOSFET Q6 and the first end of the resistor R36, respectively. The 7th pin of the boost charging chip U2 is electrically connected to the second end of the resistor R36, the corresponding end of the constant voltage circuit, and the first end of the capacitor C25, and the second end of the capacitor C25 is grounded; the 8th pin of the boost charging chip U2 is electrically connected to the gate of the MOSFET Q6 and the first end of the capacitor C24, respectively, and the second end of the capacitor C24 is grounded; the second end of the diode D9 is electrically connected to the first end of the capacitor C23 and the drain of the MOSFET Q6, respectively, and the second end of the capacitor C23 is grounded.

4. The battery charging constant current and constant voltage circuit according to claim 3, characterized in that: The model of the boost charging chip U2 is LP28400ASPF.

5. The battery charging constant current and constant voltage circuit according to claim 3, characterized in that: The constant voltage circuit includes a power supply chip U20, a capacitor C20, a capacitor C21, and a capacitor C36; the first pin of the power supply chip U20 is electrically connected to the first ends of the capacitors C21, C20, and C36 and is grounded, the second pin of the power supply chip U20 is electrically connected to the seventh pin of the voltage charging chip U2, the capacitor C20, and the second ends of the capacitor C36, and the third pin of the power supply chip U20 is electrically connected to the second end of the capacitor C21.

6. The battery charging constant current and constant voltage circuit according to claim 5, characterized in that: The model of the power chip U20 is SE8650.

7. The battery charging constant current and constant voltage circuit according to claim 1, characterized in that: The charging management circuit includes a synchronous buck charging chip U6 and its peripheral circuits, and a TYPE-C interface; the corresponding end of the synchronous buck charging chip U6 is electrically connected to the corresponding end of the TYPE-C interface; the model of the synchronous buck charging chip U6 is IU5987T.

8. The battery charging constant current and constant voltage circuit according to claim 1, characterized in that: The battery protection circuit includes a battery protection chip U3, an MXN3380 chip U2, a thermistor R12, a resistor R13, a resistor R14, a capacitor C7, a capacitor C8, a capacitor C9, a capacitor C10, a capacitor C11, a capacitor C12, and a capacitor C13; the first pin and the fourth pin of the battery protection chip U3 are correspondingly connected to the fifth pin and the fourth pin of the MXN3380 chip U2, and the second pin of the battery protection chip U3 is electrically connected to the first pin of the MXN3380 chip U2, the second pin of the MXN3380 chip U2, the third pin of the MXN3380 chip U2, the first end of the capacitor C13, and the first end of the capacitor C11 via the resistor R14; the first pin of the battery protection chip U3 is electrically connected to the first pin of the MXN3380 chip U2, the second pin of the MXN3380 chip U2, the third pin of the MXN3380 chip U2, the first end of the capacitor C13, and the first end of the capacitor C11. Pin 5 is electrically connected to the first end of the resistor R13 and the first end of the capacitor C8 respectively; the second end of the resistor R13 is electrically connected to the first end of the thermistor R12 and the first end of the capacitor C7 respectively; the second end of the capacitor C7 is electrically connected to the second end of the capacitor C11; the second end of the capacitor C13 is electrically connected to the 8th pin of the MXN3380 chip U2, the 7th pin of the MXN3380 chip U2, the 6th pin of the MXN3380 chip U2, the 6th pin of the battery protection chip U3, the second end of the capacitor C8, the first end of the capacitor C9, and the first end of the capacitor C10 respectively through the capacitor C12; the second end of the thermistor R12 is electrically connected to the second end of the capacitor C9 and the second end of the capacitor C10 respectively.

9. The battery charging constant current and constant voltage circuit according to claim 8, characterized in that: The model of the battery protection chip U3 is R5478N218CD.

10. The battery charging constant current and constant voltage circuit according to claim 1, characterized in that: The power detection circuit includes a battery power meter chip U1 and its peripheral circuits. The model of the battery power meter chip U1 is CW2017AAAD.

Images