Battery protection circuit, battery circuit, and electronic device

Abstract

The utility model discloses a kind of battery protection circuit, battery circuit and electronic equipment, it is related to the technical field of battery.The battery protection circuit of this, first protection circuit and second protection circuit, first protection circuit is used to when the charging voltage of battery reaches first voltage value or charging current reaches first current value, control battery stops charging;And for when the discharge voltage of battery reaches second voltage value or discharge current reaches second current value, control battery stops discharging.Second protection circuit is used to when the charging current detected by power detection circuit reaches the maximum charging current of battery, control battery stops charging;And, second protection chip is used to when the discharge current detected by power detection circuit reaches the maximum discharge current of battery, control battery stops discharging.The battery protection circuit proposed in the utility model has double-layer protection effect to battery, and can improve the use safety of battery.

Description

Technical Field

[0001] This utility model relates to the technical field of batteries, and in particular to a battery protection circuit, a battery circuit, and an electronic device. Background Technology

[0002] In existing electronic product designs, when the main circuit loses its protection function due to component failure, such as a short circuit, it relies on the battery's built-in primary protection circuit to achieve overcurrent / overvoltage protection. However, existing overcurrent / overvoltage protection systems, to avoid false triggering, typically set protection thresholds that are too high, far exceeding the battery's maximum allowable current. This results in the actual current exceeding the cell's maximum allowable current when the main circuit fails, yet still not reaching the protection trigger threshold, preventing the protection mechanism from activating and reducing battery safety. Utility Model Content

[0003] The main purpose of this invention is to provide a battery protection circuit, a battery circuit, and an electronic device, which aims to improve the safety of battery use.

[0004] To achieve the above objectives, this utility model proposes a battery protection circuit, which includes: The first protection circuit includes a first protection chip, a first MOSFET, and a second MOSFET. The first protection chip has a charging control terminal and a discharging control terminal. The controlled terminal of the first MOSFET is connected to the charging control terminal, and the controlled terminal of the second MOSFET is connected to the discharging control terminal. The first MOSFET and the second MOSFET are connected in series in the path between the battery and the load terminal and the power supply terminal. The first protection chip controls the first MOSFET to turn off when the battery charging voltage reaches a first voltage value or the charging current reaches a first current value, so as to stop charging. The first protection chip also controls the second MOSFET to turn off when the battery discharging voltage reaches a second voltage value or the discharging current reaches a second current value, so as to stop discharging. The second protection circuit includes a second protection chip, a power detection circuit, and a switching circuit. The power detection circuit is used to connect to the battery and to detect the charging current and discharging current of the battery. A switching circuit, wherein the switching circuit is connected to the first protection chip, and the controlled terminal of the switching circuit is connected to the second protection chip; The second protection chip is connected to the power detection circuit. When the charging current detected by the power detection circuit reaches the maximum charging current of the battery, the second protection chip controls the charging control terminal to turn off the first MOSFET through the switching circuit. The second protection chip is also used to control the discharge control terminal to turn off the second MOSFET through the switching circuit when the discharging current detected by the power detection circuit reaches the maximum discharging current of the battery.

[0005] In one embodiment, the second protection chip has a first terminal and a second terminal, the power detection circuit is connected to the first terminal of the second protection chip, and the controlled terminal of the switching circuit is connected to the second terminal of the second protection chip.

[0006] In one embodiment, the second protection chip has a third terminal; the battery protection circuit further includes: A charge / discharge state detection circuit is electrically connected to the third terminal of the second protection chip. The charge / discharge state detection circuit is used to output a discharge state detection signal when the battery is detected to be discharging, and the charge / discharge state detection circuit is used to output a charging state detection signal when the battery is detected to be charging. The second protection chip is used to control the battery to stop discharging through the switching circuit when a discharge state detection signal is received through the charge / discharge state detection circuit and the discharge current detected by the power detection circuit reaches the maximum discharge current of the battery. The second protection chip is used to control the battery to stop charging via the switching circuit when a charging status detection signal is received through the charging / discharging status detection circuit and the charging current detected by the power detection circuit reaches the maximum charging current of the battery.

[0007] In one embodiment, the second protection chip further has a fourth terminal, and the second protection circuit further includes: The LDO power supply circuit is used to connect to the battery to transfer the battery's electrical energy to the second protection chip.

[0008] In one embodiment, the power detection circuit includes a first resistor, a second resistor, a third resistor, a first capacitor, and a second capacitor; The first end of the first resistor is used to connect to the battery. The second end of the first resistor is connected to the first end of the first capacitor, the first end of the second resistor, and the first end of the third resistor. The second end of the first resistor is grounded. The second end of the third resistor is connected to the first end of the second capacitor. The second end of the second capacitor, the second end of the second resistor, and the second end of the first capacitor are grounded. The second end of the third resistor and the first end of the second capacitor are connected to the first end of the second protection chip.

[0009] In one embodiment, the switching circuit includes a third MOSFET, a fourth MOSFET, a first power switch, and a second power switch; The controlled terminals of the first power switch and the second power switch are connected to the second terminal of the second protection chip. The first terminals of the first power switch and the second power switch are grounded. The second terminal of the first power switch is connected to the discharge control terminal of the first protection chip, and the second terminal of the second power switch is connected to the charging control terminal of the first protection chip. The controlled terminal of the third MOSFET is connected to the second terminal of the first power switch and the discharge control terminal of the first protection chip. The first terminal of the third MOSFET is grounded. The second terminal of the third MOSFET is connected to the first terminal of the fourth MOSFET. The second terminal of the fourth MOSFET is used to connect to the battery. The controlled terminal of the fourth MOSFET is connected to the second terminal of the second power switch and the charging control terminal of the first protection chip.

[0010] In one embodiment, the switching circuit further includes a fourth resistor, a fifth resistor, a sixth resistor, and a seventh resistor; The first end of the fourth resistor and the first end of the fifth resistor are connected to the second end of the second protection chip. The second end of the fourth resistor is connected to the first end of the sixth resistor and the controlled end of the first power switch. The second end of the sixth resistor and the first end of the seventh resistor are grounded. The second end of the seventh resistor is connected to the second end of the fifth resistor and the controlled end of the second power switch.

[0011] In one embodiment, the charge / discharge state detection circuit includes: a control chip, an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a thirteenth resistor, and a third capacitor, a fourth capacitor, a fifth capacitor, a sixth capacitor, and a seventh capacitor. The control chip includes a first pin to a fifth pin. The first pin of the control chip is connected to the first terminal of the third capacitor, the first terminal of the eighth resistor, and the first terminal of the ninth resistor. The second terminal of the ninth resistor is connected to the first terminal of the fourth capacitor. The second terminal of the third capacitor, the second terminal of the eighth resistor, and the second terminal of the fourth capacitor are grounded. The second pin of the control chip is connected to the first terminal of the fifth capacitor and the first terminal of the tenth resistor. The second terminal of the fifth capacitor is grounded. The second terminal of the tenth resistor is connected to the first terminal of the sixth capacitor and the third pin of the control chip through the eleventh resistor. The second terminal of the sixth capacitor is grounded. The fourth pin of the control chip is grounded; The fifth pin of the control chip is connected to the first end of the twelfth resistor and the first end of the seventh capacitor, and the second end of the seventh capacitor is grounded; The thirteenth resistor is connected in series in the path between the battery and the load terminal and the power supply terminal. The first end of the thirteenth resistor is connected to the second end of the tenth resistor, and the second end of the thirteenth resistor is connected to the second end of the twelfth resistor.

[0012] This utility model also provides a battery circuit, which includes a battery and a battery protection circuit as described above.

[0013] This application also provides an electronic device comprising the battery as described above.

[0014] This invention provides a battery protection circuit that employs a dual-level collaborative protection mechanism, effectively improving battery safety during charging and discharging. The first protection circuit, acting as the main protection, consists of a first protection chip, a first MOSFET, and a second MOSFET, providing routine protection for the battery's charging and discharging voltage and current. When the battery voltage or current exceeds a corresponding value, it can control the corresponding MOSFET to cut off the circuit, preventing the abnormal situation from escalating. However, to prevent false triggering, the threshold may be set too high, and the first protection may not respond in time. In this case, the second protection circuit, acting as a secondary protection circuit, includes a second protection chip, a power detection circuit, and a switching circuit. The power detection circuit detects the actual charging and discharging current of the battery. Once it detects that the charging or discharging current reaches or exceeds the battery's maximum allowable value, the second protection chip will forcibly control the charging and discharging control terminal of the first protection chip through the switching circuit, causing the corresponding MOSFET to turn off, thereby achieving rapid circuit breaking protection. This improves the safety of battery use. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0016] Figure 1A schematic diagram of an embodiment of the battery protection circuit provided by this utility model; Figure 2 A schematic diagram of another embodiment of the battery protection circuit provided by this utility model; Figure 3 Circuit diagram of an embodiment of the first protection circuit provided by this utility model; Figure 4 Circuit diagram of the second protection chip provided by this utility model; Figure 5 Circuit diagram of the LDO power supply circuit provided by this utility model; Figure 6 Circuit diagrams of the switching circuit and power detection circuit provided by this utility model; Figure 7 The circuit diagram of the charge / discharge state detection circuit provided by this utility model.

[0017] Explanation of icon numbers: 10. First protection circuit; 20. Second protection circuit; 21. Battery detection circuit; 22. Switching circuit; 23. Charge / discharge status detection circuit; Q1, First MOSFET; Q2, Second MOSFET; Q3, Third MOSFET; Q4, Fourth MOSFET; Q5, First Power Switch; Q6, Second Power Switch; R1, First Resistor; R2, Second Resistor; R3, Third Resistor; R4, Fourth Resistor; R5, Fifth Resistor; R6, Sixth Resistor; R7, Seventh Resistor; R8, Eighth Resistor; R9, Ninth Resistor; R10, Tenth Resistor; R11, Eleventh Resistor; R12, Twelfth Resistor; C1, First Capacitor; C2, Second Capacitor; C3, Third Capacitor; C4, Fourth Capacitor; C5, Fifth Capacitor; C6, Sixth Capacitor; C7, Seventh Capacitor; U1, first protection chip; U2, second protection chip; U3, control chip.

[0018] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. 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 scope of protection of the present utility model.

[0020] It should be noted that if the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0021] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," these descriptions are 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 with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0022] In existing electronic product designs, when the main circuit loses its protection function due to component failure, such as a short circuit, it relies on the battery's built-in primary protection circuit to achieve overcurrent / overvoltage protection. However, existing overcurrent / overvoltage protection systems, to avoid false triggering, typically set protection thresholds that are too high, far exceeding the battery's maximum allowable current. This results in the actual current exceeding the cell's maximum allowable current when the main circuit fails, yet still not reaching the protection trigger threshold, preventing the protection mechanism from activating and reducing battery safety.

[0023] To improve battery safety, this invention proposes a battery protection circuit. In one embodiment, the battery protection circuit includes a first protection circuit and a second protection circuit to achieve two-level protection.

[0024] In this embodiment, as Figure 1 and Figure 3As shown, the first protection circuit 10 includes a first protection chip U1, a first MOSFET Q1, and a second MOSFET Q2. The first protection chip U1 has a charging control terminal and a discharging control terminal. The controlled terminal of the first MOSFET Q1 is connected to the charging control terminal, and the controlled terminal of the second MOSFET Q2 is connected to the discharging control terminal. The first MOSFET Q1 and the second MOSFET Q2 are connected in series in the path between the battery and the load terminal and the power supply terminal. The first protection chip U1 controls the first MOSFET Q1 to turn off when the battery charging voltage reaches a first voltage value or the charging current reaches a first current value, so as to stop charging. The first protection chip U1 controls the second MOSFET Q2 to turn off when the battery discharging voltage reaches a second voltage value or the discharging current reaches a second current value, so as to stop discharging.

[0025] It is understandable that, such as Figure 1 and Figure 3 As shown, the first protection circuit 10 consists of a first protection chip U1, a first MOSFET Q1, and a second MOSFET Q2. The first protection chip U1 controls the conduction and cutoff of the second MOSFET Q2 and the first MOSFET Q1 through its charging control terminal (CO terminal) and discharging control terminal (DO terminal), respectively. Specifically, the first MOSFET Q1 is controlled by the CO terminal; the first MOSFET Q2 is controlled by the DO terminal. The first protection chip U1 monitors the battery voltage and current in real time. When an abnormality (such as overcharge, over-discharge, or overcurrent) is detected, it adjusts the levels of CO and DO to force the MOSFETs to turn off, cutting off the charging and discharging path, thereby protecting the battery safety.

[0026] In one feasible implementation, under normal charging and discharging conditions, the CO terminal of the first protection chip U1 outputs a high level, turning on the first MOSFET Q1 and allowing charging current to flow into the battery; simultaneously, the DO terminal outputs a high level, turning on the second MOSFET Q2 and allowing the battery to supply power to the load. When charging is abnormal (such as excessive voltage or current exceeding a threshold), the first protection chip U1 triggers the CO terminal to output a low level, turning off the first MOSFET Q1 and cutting off the charging path; when discharging is abnormal (such as excessive voltage or current exceeding the limit), the first protection chip U1 triggers the DO terminal to output a low level, turning off the second MOSFET Q2 and terminating the discharging process.

[0027] In this embodiment, as Figure 1As shown, the second protection circuit 20 includes a second protection chip U2, a power detection circuit, and a switching circuit 22. The power detection circuit is connected to the battery and is used to detect the charging current and discharging current of the battery. The switching circuit 22 is connected to the first protection chip U1, and the controlled terminal of the switching circuit 22 is connected to the second protection chip U2. The second protection chip U2 is connected to the power detection circuit. When the charging current detected by the power detection circuit reaches the maximum charging current of the battery, the second protection chip U2 controls the charging control terminal to control the first MOSFET Q1 to turn off through the switching circuit 22. The second protection chip U2 is also used to control the discharging control terminal to control the second MOSFET Q2 to turn off when the discharging current detected by the power detection circuit reaches the maximum discharging current of the battery.

[0028] The second protection circuit 20 employs a redundant design to provide secondary protection for battery charging and discharging. The power detection circuit monitors the battery's charging and discharging current in real time and feeds it back to the second protection chip U2. When the charging current reaches the battery's maximum allowable charging current or the discharging current reaches the maximum allowable discharging current, the second protection chip U2 immediately sends a forced control signal to the charging or discharging control terminal of the first protection chip U1 via the switching circuit 22, directly driving the first MOSFET Q1 or the second MOSFET Q2 to turn off, thus cutting off the abnormal current path. In this way, even if the first protection circuit 10 fails to respond in time due to an excessively high current protection threshold or a main circuit failure, the second protection circuit 20 can still independently perform rapid circuit breaking protection, thereby filling the blind spot of the first protection circuit 10 and ensuring battery safety.

[0029] Understandably, with the continuous upgrading of safety standards for portable battery packs, the safety testing requirements for battery-powered devices have significantly increased. Testing organizations, when simulating failure scenarios, must short-circuit key components (such as MOSFETs) one by one, and strictly require that the charging and discharging current during testing must not exceed the maximum allowable current of the battery cell. In this context, the traditional design relying solely on the first protection circuit 10 has significant shortcomings. To avoid false triggering, the overcurrent threshold of the first protection circuit 10 is usually set too high, resulting in the actual charging and discharging current exceeding the cell's safety range when the main circuit fails, yet failing to trigger protection. Ultimately, this fails to meet safety certification requirements, affecting product launch and user safety experience. Therefore, the battery protection circuit of this invention also includes a second protection circuit 20. This circuit monitors the charging and discharging current in real time through an independent power detection module. When the first-level protection fails or the threshold is insufficient, the second protection chip U2 actively takes over the control logic, forcibly cutting off the charging and discharging path. This ensures that even if the main circuit components are short-circuited or fail, the current is still strictly limited to the maximum allowable range of the battery cell, effectively solving the technical problem of current exceeding limits in simulated failure testing and improving battery safety. It should be noted that the first current value and the second current value in the first protection circuit 10 are greater than the maximum allowable current of the battery.

[0030] In summary, this utility model provides a battery protection circuit that employs a dual-level collaborative protection mechanism, effectively improving battery safety during charging and discharging. The first protection circuit 10, serving as the main protection, consists of a first protection chip U1, a first MOSFET Q1, and a second MOSFET Q2, providing routine protection for the battery's charging and discharging voltage and current. When the battery voltage or current exceeds a corresponding value, it can control the corresponding MOSFET to cut off the circuit, preventing the abnormal situation from escalating. However, to prevent false triggering, the threshold may be set too high, and the first protection may not respond in time. In this case, the second protection circuit 20 serves as a secondary protection circuit, including a second protection chip U2, a power detection circuit, and a switching circuit 22. The power detection circuit detects the actual charging and discharging current of the battery. Once it detects that the charging or discharging current reaches or exceeds the battery's maximum allowable value, the second protection chip U2 will forcibly control the charging and discharging control terminal of the first protection chip U1 through the switching circuit 22, causing the corresponding MOSFET to be cut off, thereby achieving rapid circuit breaking protection. This improves the safety of battery use.

[0031] In one embodiment, such as Figure 4 As shown, the second protection chip U2 has a first terminal and a second terminal. The power detection circuit is connected to the first terminal of the second protection chip U2, and the controlled terminal of the switching circuit 22 is connected to the second terminal of the second protection chip U2.

[0032] In one embodiment, such as Figure 2 and Figure 4 As shown, the second protection chip U2 has a third terminal; the battery protection circuit further includes: a charge / discharge state detection circuit 23, which is electrically connected to the third terminal of the second protection chip U2. The charge / discharge state detection circuit 23 is used to output a discharge state detection signal when the battery is detected to be discharging, and to output a charging state detection signal when the battery is detected to be charging. The second protection chip U2 is used to control the battery to stop discharging through the switching circuit 22 when it receives a discharge state detection signal through the charge / discharge state detection circuit 23 and the discharge current detected by the power detection circuit reaches the maximum discharge current of the battery. The second protection chip U2 is also used to control the battery to stop charging through the switching circuit 22 when it receives a charging state detection signal through the charge / discharge state detection circuit 23 and the charging current detected by the power detection circuit reaches the maximum charging current of the battery.

[0033] Understandably, the charge / discharge state detection circuit 23 monitors the battery's current direction and operating mode (charging / discharging) in real time, and outputs a corresponding charge state detection signal or discharge state detection signal to the third terminal of the second protection chip U2. Optionally, when the battery is in a charging state (current flows from the external power source to the battery), the detection circuit outputs a charging signal; when the battery is in a discharging state (current flows from the battery to the load), it outputs a discharging signal.

[0034] In this embodiment, by distinguishing between charging and discharging states, the second protection chip U2 can independently trigger protection actions for different scenarios (charging or discharging). For example, it can detect excessive charging current and cut off the charging path only during charging, avoiding accidental triggering of charging protection logic during discharging and improving the accuracy of system response.

[0035] In one embodiment, such as Figure 3 As shown, the second protection chip U2 also has a fourth terminal, and the second protection circuit 20 further includes an LDO power supply circuit, which is used to connect to a battery to transmit the battery's electrical energy to the second protection chip U2.

[0036] In one feasible implementation, such as Figure 4 and Figure 5 As shown, the LDO power supply circuit (low dropout linear regulator) converts the battery voltage (e.g., 3.7V~4.2V) into the stable operating voltage (e.g., 3.3V or 5V) required by the second protection chip U2, ensuring that it can still operate normally when the battery voltage fluctuates.

[0037] In this embodiment, the fourth terminal of the second protection chip U2 serves as the power input terminal, receiving the output voltage of the LDO power supply circuit, and is independent of the main circuit power supply system.

[0038] In one embodiment, such as Figure 6 As shown, the power detection circuit includes a first resistor R1, a second resistor R2, a third resistor R3, a first capacitor C1, and a second capacitor C2. The first end of the first resistor R1 is connected to the battery. The second end of the first resistor R1 is connected to the first end of the first capacitor C1, the first end of the second resistor R2, and the first end of the third resistor R3. The second end of the first resistor R1 is grounded. The second end of the third resistor R3 is connected to the first end of the second capacitor C2. The second ends of the second capacitor C2, the second ends of the second resistor R2, and the second ends of the first capacitor C1 are grounded. The second end of the third resistor R3 and the first end of the second capacitor C2 are connected to the first end of the second protection chip U2.

[0039] The power detection circuit achieves precise monitoring of the battery's charging and discharging status through a combination of resistor voltage division and capacitor filtering. Specifically, the battery voltage is divided by the first resistor R1, and its second terminal is grounded and connected to the first terminals of the second resistor R2 and the third resistor R3, forming a voltage divider network. The second resistor R2 and the third resistor R3 further form a secondary voltage divider path, outputting the divided signal through the second terminal of the third resistor R3 to the first terminal of the second protection chip U2. Simultaneously, the first capacitor C1 is connected in parallel to the voltage divider node of the second resistor R2, and the second capacitor C2 is connected in parallel to the output node of the third resistor R3. Both are grounded to filter out high-frequency noise and interference in the voltage divider signal, ensuring the stability of the IN / OUT-AD signal. The first terminal of the second protection chip U2 detects this IN / OUT-AD signal in real time. Through the voltage division ratio of the first resistor R1-second resistor R2-third resistor R3 and the filtering effect of the first capacitor C1 and the second capacitor C2, it effectively reflects the battery's charging and discharging current status, thereby providing the second protection chip U2 with a reliable current sampling value and enabling rapid response and protection against abnormal charging and discharging.

[0040] In one embodiment, such as Figure 6As shown, the switching circuit 22 includes a third MOSFET Q3, a fourth MOSFET Q4, a first power switch Q5, and a second power switch Q6. The controlled terminals of the first power switch Q5 and the second power switch Q6 are connected to the second terminal of the second protection chip U2. The first terminals of the first power switch Q5 and the second power switch Q6 are grounded. The second terminal of the first power switch Q5 is connected to the discharge control terminal of the first protection chip U1, and the second terminal of the second power switch Q6 is connected to the charging control terminal of the first protection chip U1. The controlled terminal of the third MOSFET Q3 is connected to the second terminal of the first power switch Q5 and the discharge control terminal of the first protection chip U1. The first terminal of the third MOSFET Q3 is grounded. The second terminal of the third MOSFET Q3 is connected to the first terminal of the fourth MOSFET Q4. The second terminal of the fourth MOSFET Q4 is used to connect to the battery. The controlled terminal of the fourth MOSFET Q4 is connected to the second terminal of the second power switch Q6 and the charging control terminal of the first protection chip U1.

[0041] It is understandable that, such as Figure 6 As shown, Figure 6 The DO / CO-OFF signal can be either a DO-OFF signal to control the stopping of discharge or a CO-OFF signal to control the stopping of charging.

[0042] In one feasible implementation, when the battery discharge current exceeds the battery's maximum discharge current, the second protection chip U2 forces the discharge control signal (DO-EN) of the first protection chip U1 to ground level via the first power switch Q5, causing the discharge control pin of the first protection chip U1 to output a low level, driving the third MOSFET Q3 to turn off and cutting off the discharge path. When the charging current exceeds the maximum charging current, the second protection chip U2 forces the charging control signal (CO-EN) of the first protection chip U1 to ground level via the second power switch Q6, causing the charging control pin (CO) to output a low level, driving the fourth MOSFET Q4 to turn off and terminating the charging process. Thus, the second protection chip U2 directly intervenes in the DO and CO signals of the first protection chip U1 via the first power switch Q5 and the second power switch Q6. Even if the first protection circuit 10 fails to respond due to an excessively high threshold setting or a main circuit failure, it can still force the control signal low through physical grounding, ensuring the MOSFET is quickly turned off.

[0043] In one feasible implementation, the third MOSFET Q3 can be Figure 3 The first MOSFET Q1; the fourth MOSFET Q4 can be Figure 3 The second MOSFET Q2 in the circuit.

[0044] In one embodiment, such as Figure 6As shown, the switching circuit 22 further includes a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, and a seventh resistor R7. The first ends of the fourth resistor R4 and the fifth resistor R5 are connected to the second end of the second protection chip U2. The second end of the fourth resistor R4 is connected to the first end of the sixth resistor R6 and the controlled terminal of the first power switch Q5. The second end of the sixth resistor R6 and the first end of the seventh resistor R7 are grounded. The second end of the seventh resistor R7 is connected to the second end of the fifth resistor R5 and the controlled terminal of the second power switch Q6. In this embodiment, through the synergistic effect of the fourth resistor R4, the fifth resistor R5, the sixth resistor R6, and the seventh resistor R7, the risk of false triggering of the first power switch Q5 and the second power switch Q6 is effectively suppressed.

[0045] In one embodiment, such as Figure 7 As shown, the charge / discharge state detection circuit 23 includes: a control chip U3, eighth resistors R8 to thirteenth resistors, and third capacitors C3 to seventh capacitors C7; the control chip U3 includes a first pin to a fifth pin, the first pin of the control chip U3 being connected to the first terminal of the third capacitor C3, the first terminal of the eighth resistor R8, and the first terminal of the ninth resistor R9, the second terminal of the ninth resistor R9 being connected to the first terminal of the fourth capacitor C4, and the second terminals of the third capacitor C3, the eighth resistor R8, and the fourth capacitor C4 being grounded; the second pin of the control chip U3 is connected to the first terminal of the fifth capacitor C5 and the first terminal of the tenth resistor R10. The second terminal of the fifth capacitor C5 is grounded. The second terminal of the tenth resistor R10 is connected to the first terminal of the sixth capacitor C6 and the third pin of the control chip U3 through the eleventh resistor R11. The second terminal of the sixth capacitor C6 is grounded. The fourth pin of the control chip U3 is grounded. The fifth pin of the control chip U3 is connected to the first terminal of the twelfth resistor R12 and the first terminal of the seventh capacitor C7. The second terminal of the seventh capacitor C7 is grounded. The thirteenth resistor is connected in series in the path between the battery and the load terminal and the power supply terminal. The first terminal of the thirteenth resistor is connected to the second terminal of the tenth resistor R10, and the second terminal of the thirteenth resistor is connected to the second terminal of the twelfth resistor R12.

[0046] In this embodiment, the thirteenth resistor is connected in series in the path between the battery and the load / power supply, serving as a current sampling resistor. When the external power supply charges the battery, the current direction is power supply → thirteenth resistor → battery, and the voltage drop across the thirteenth resistor is V+ (positive polarity). When the battery supplies power to the load, the current direction is battery → thirteenth resistor → load, and the voltage drop across the thirteenth resistor is V- (negative polarity). By detecting the polarity (positive / negative) of the voltage across the thirteenth resistor, the charging / discharging direction can be directly determined.

[0047] Understandably, resistors R8 (eighth) and R9 (ninth), along with capacitors C3 (third) and C4 (fourth), form a low-pass filter to remove high-frequency noise and ensure the stability of the reference voltage received by control chip U3. Capacitor C3 is connected in parallel with resistor R8 for initial filtering of the input signal. Resistor R9 is connected in series with capacitor C4 to further smooth signal fluctuations. Resistors R10 and R11 (eleventh), along with capacitors C5 (fifth) and C6 (sixth), form an impedance matching and filtering network. Resistor R10 and capacitor C5 form an input filter to prevent high-frequency interference from affecting the judgment of control chip U3. Resistor R11 and capacitor C6 together adjust the dynamic response of the signal, ensuring a balance between detection speed and stability. Resistor R12 and capacitor C7 (seventh) form a power supply filter to suppress the impact of power supply noise on control chip U3 and ensure its operational stability.

[0048] like Figure 7 As shown, Figure 7 The ICHARGE-AD in the code is used to output a discharge status detection signal or a charging status detection signal.

[0049] In one embodiment of this utility model, the second protection chip U2, based on the charging / discharging state detection circuit 23 detecting that the circuit is in a charging state, and combined with the current value detected by the power supply detection circuit 21, determines that the current value is greater than the battery's maximum charging current using an internal algorithm, and thus controls the battery to stop charging via the switching circuit 22. Conversely, based on the charging / discharging state detection circuit 23 detecting that the circuit is in a discharging state, and combined with the current value detected by the power supply detection circuit 21, determines that the current value is greater than the battery's maximum discharging current using an internal algorithm, and thus controls the battery to stop discharging via the switching circuit 22.

[0050] This utility model also provides a battery circuit, which includes a battery and a battery protection circuit as described above. It should be noted that the battery protection circuit included in this battery circuit can be specifically implemented with reference to the battery protection circuit in any of the above embodiments. Therefore, this battery circuit can at least achieve all the beneficial effects brought by the battery protection circuit in the above embodiments, and will not be elaborated further here.

[0051] This application also provides an electronic device comprising the battery as described above. It should be noted that the battery circuitry included in this electronic device can be specifically implemented with reference to the battery circuitry in the above embodiments. Therefore, this electronic device can at least achieve all the beneficial effects brought by the battery circuitry in the above embodiments, and will not be elaborated further here.

[0052] It is understood that this battery integrates a high-precision charge and discharge detection and protection circuit, which can monitor the current direction in real time, prevent overcurrent and false triggering, thereby improving the overall system's safety and stability. Specific examples applicable to the electronic devices described in this application include, but are not limited to: smartphones, tablets, laptops, wearable devices (such as smartwatches and wireless headphones), power tools, drones, energy storage systems, and various portable or mobile electronic products that rely on battery power. By adopting the battery and its control circuit described in this application, these devices can achieve more reliable power management under complex operating conditions, extend battery life, and have higher safety in use.

Claims

1. A battery protection circuit, characterized in that, The battery protection circuit includes: The first protection circuit includes a first protection chip, a first MOSFET, and a second MOSFET. The first protection chip has a charging control terminal and a discharging control terminal. The controlled terminal of the first MOSFET is connected to the charging control terminal, and the controlled terminal of the second MOSFET is connected to the discharging control terminal. The first MOSFET and the second MOSFET are connected in series in the path between the battery and the load terminal and the power supply terminal. The first protection chip controls the first MOSFET to turn off when the battery charging voltage reaches a first voltage value or the charging current reaches a first current value, so as to stop charging. The first protection chip also controls the second MOSFET to turn off when the battery discharging voltage reaches a second voltage value or the discharging current reaches a second current value, so as to stop discharging. The second protection circuit includes a second protection chip, a power detection circuit, and a switching circuit. The power detection circuit is used to connect to the battery and to detect the charging current and discharging current of the battery. A switching circuit, wherein the switching circuit is connected to the first protection chip, and the controlled terminal of the switching circuit is connected to the second protection chip; The second protection chip is connected to the power detection circuit. When the charging current detected by the power detection circuit reaches the maximum charging current of the battery, the second protection chip controls the charging control terminal to turn off the first MOSFET through the switching circuit. The second protection chip is also used to control the discharge control terminal to turn off the second MOSFET through the switching circuit when the discharging current detected by the power detection circuit reaches the maximum discharging current of the battery.

2. The battery protection circuit as described in claim 1, characterized in that, The second protection chip has a first terminal and a second terminal. The power detection circuit is connected to the first terminal of the second protection chip, and the controlled terminal of the switching circuit is connected to the second terminal of the second protection chip.

3. The battery protection circuit as described in claim 2, characterized in that, The second protection chip has a third terminal; the battery protection circuit further includes: A charge / discharge state detection circuit is electrically connected to the third terminal of the second protection chip. The charge / discharge state detection circuit is used to output a discharge state detection signal when the battery is detected to be discharging, and the charge / discharge state detection circuit is used to output a charging state detection signal when the battery is detected to be charging. The second protection chip is used to control the battery to stop discharging through the switching circuit when a discharge state detection signal is received through the charge / discharge state detection circuit and the discharge current detected by the power detection circuit reaches the maximum discharge current of the battery. The second protection chip is used to control the battery to stop charging via the switching circuit when a charging status detection signal is received through the charging / discharging status detection circuit and the charging current detected by the power detection circuit reaches the maximum charging current of the battery.

4. The battery protection circuit as described in claim 3, characterized in that, The second protection chip also has a fourth terminal, and the second protection circuit further includes: The LDO power supply circuit is used to connect to the battery to transfer the battery's electrical energy to the second protection chip.

5. The battery protection circuit as described in claim 3, characterized in that, The power detection circuit includes a first resistor, a second resistor, a third resistor, a first capacitor, and a second capacitor; The first end of the first resistor is used to connect to the battery. The second end of the first resistor is connected to the first end of the first capacitor, the first end of the second resistor, and the first end of the third resistor. The second end of the first resistor is grounded. The second end of the third resistor is connected to the first end of the second capacitor. The second end of the second capacitor, the second end of the second resistor, and the second end of the first capacitor are grounded. The second end of the third resistor and the first end of the second capacitor are connected to the first end of the second protection chip.

6. The battery protection circuit as described in claim 3, characterized in that, The switching circuit includes a third MOSFET, a fourth MOSFET, a first power switch, and a second power switch; The controlled terminals of the first power switch and the second power switch are connected to the second terminal of the second protection chip. The first terminals of the first power switch and the second power switch are grounded. The second terminal of the first power switch is connected to the discharge control terminal of the first protection chip, and the second terminal of the second power switch is connected to the charging control terminal of the first protection chip. The controlled terminal of the third MOSFET is connected to the second terminal of the first power switch and the discharge control terminal of the first protection chip. The first terminal of the third MOSFET is grounded. The second terminal of the third MOSFET is connected to the first terminal of the fourth MOSFET. The second terminal of the fourth MOSFET is used to connect to the battery. The controlled terminal of the fourth MOSFET is connected to the second terminal of the second power switch and the charging control terminal of the first protection chip.

7. The battery protection circuit as described in claim 6, characterized in that, The switching circuit also includes a fourth resistor, a fifth resistor, a sixth resistor, and a seventh resistor; The first end of the fourth resistor and the first end of the fifth resistor are connected to the second end of the second protection chip. The second end of the fourth resistor is connected to the first end of the sixth resistor and the controlled end of the first power switch. The second end of the sixth resistor and the first end of the seventh resistor are grounded. The second end of the seventh resistor is connected to the second end of the fifth resistor and the controlled end of the second power switch.

8. The battery protection circuit as described in claim 3, characterized in that, The charge / discharge status detection circuit includes: a control chip, an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a thirteenth resistor, and a third capacitor, a fourth capacitor, a fifth capacitor, a sixth capacitor, and a seventh capacitor; The control chip includes a first pin to a fifth pin. The first pin of the control chip is connected to the first terminal of the third capacitor, the first terminal of the eighth resistor, and the first terminal of the ninth resistor. The second terminal of the ninth resistor is connected to the first terminal of the fourth capacitor. The second terminal of the third capacitor, the second terminal of the eighth resistor, and the second terminal of the fourth capacitor are grounded. The second pin of the control chip is connected to the first terminal of the fifth capacitor and the first terminal of the tenth resistor. The second terminal of the fifth capacitor is grounded. The second terminal of the tenth resistor is connected to the first terminal of the sixth capacitor and the third pin of the control chip through the eleventh resistor. The second terminal of the sixth capacitor is grounded. The fourth pin of the control chip is grounded; The fifth pin of the control chip is connected to the first end of the twelfth resistor and the first end of the seventh capacitor, and the second end of the seventh capacitor is grounded; The thirteenth resistor is connected in series in the path between the battery and the load terminal and the power supply terminal. The first end of the thirteenth resistor is connected to the second end of the tenth resistor, and the second end of the thirteenth resistor is connected to the second end of the twelfth resistor.

9. A battery circuit, characterized in that, The battery circuit includes a battery and a battery protection circuit as described in any one of claims 1 to 8.

10. An electronic device, characterized in that, The electronic device includes the battery as described in claim 9.

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