Battery protection circuit, battery assembly and electronic device

Abstract

The invention provides a battery protection circuit, which comprises a main control unit and a main switch unit, and is characterized in that the main switch unit is connected in series with a system circuit, and the system circuit comprises a main load and an auxiliary load which are connected in parallel; an over-discharge protection module; when the over-discharge protection module judges that the battery voltage is greater than or equal to a preset first threshold voltage, the main control unit controls the main switch unit to be normally switched on; when the over-discharge protection module judges that the battery voltage is smaller than the first threshold voltage and larger than or equal to a preset second threshold voltage, the main control unit controls the main switch unit to be intermittently conducted; when the over-discharge protection module judges that the battery voltage is smaller than the second threshold voltage, the main control unit controls the main switch unit to be disconnected and cut off, and the second threshold voltage is smaller than the first threshold voltage. The embodiment of the invention further provides a battery assembly and an electronic device.

Description

Technical Field

[0001] This application relates to the field of battery protection, and more particularly to a battery protection circuit, battery assembly, and electronic device. Background Technology

[0002] Battery modules are widely used in electronic devices such as mobile phones, tablets, Bluetooth headsets, and smartwatches. They connect to the system circuitry of these devices to provide a more flexible operating environment, freeing them from the constraints of sockets and power cords. Generally, a battery module includes a battery, a battery protection circuit electrically connected to the battery, and the system circuitry to supply power to the system.

[0003] The battery protection circuit includes various protection units, such as overcharge protection units, over-discharge protection modules, charging overcurrent protection units, and discharging overcurrent protection units, to provide various protections for the battery. To provide protection, the battery protection units collect information such as battery voltage and current and transmit it to each protection unit. By comparing this information with preset thresholds, it determines whether to take protective measures.

[0004] Generally, as the system circuit operates normally, the battery level gradually decreases. When the battery level drops below the threshold of the over-discharge protection module, the over-discharge protection module controls the main switch unit to disconnect, and the system circuit is de-energized. However, in some usage scenarios, the system circuit may include a remote positioning module, such as a GPS device. When over-discharge protection is activated, all system circuits, including the remote positioning module, are de-energized, rendering location tracking impossible. This is particularly problematic with smartwatches worn by children, where parents are unable to locate their children, causing significant anxiety. This is a very troublesome issue that severely degrades the user experience. Furthermore, current electronic devices typically have a limited lifespan of one to two days. After this period, triggering over-discharge protection often renders the remote positioning function unusable, hindering normal user operation and compromising user safety. Summary of the Invention

[0005] The technical problem to be solved by the embodiments of this application is to provide a battery protection circuit, battery component, and electronic device to address the shortcomings of the prior art. This allows the auxiliary load to continue operating even when the battery voltage is relatively low.

[0006] To address the aforementioned technical problems, a first aspect of this application provides a battery protection circuit, comprising:

[0007] The system includes a main control unit and a main switch unit, wherein the main control unit is connected to the control terminal of the main switch unit, the main switch unit is used to connect in series with the system circuit, and the main switch unit is used to control whether the battery supplies power to the system circuit. The system circuit includes a main load and an auxiliary load connected in parallel.

[0008] The over-discharge protection module has its input terminal connected to the battery voltage and its output terminal connected to the main control unit.

[0009] Specifically, when the over-discharge protection module determines that the battery voltage is greater than or equal to a preset first threshold voltage, the main control unit controls the main switch unit to conduct normally. When the over-discharge protection module determines that the battery voltage is less than the first threshold voltage but greater than or equal to a preset second threshold voltage, the main control unit controls the main switch unit to conduct intermittently. When the over-discharge protection module determines that the battery voltage is less than the second threshold voltage, the main control unit controls the main switch unit to disconnect, where the second threshold voltage is less than the first threshold voltage.

[0010] Optionally, when the battery voltage is less than the first threshold voltage and greater than or equal to the second threshold voltage, the duty cycle of the main switching unit decreases step by step as the battery voltage decreases.

[0011] Optionally, the over-discharge protection module includes a first over-discharge protection unit and n over-discharge protection sub-units, where n is an integer greater than or equal to 2. The input terminal of the first over-discharge protection unit is connected to a first sampling voltage and a first reference voltage. The input terminals of the n over-discharge protection sub-units are respectively connected to a first sampling voltage, a second first reference sub-voltage, a second second reference sub-voltage, ..., a second nth reference sub-voltage. The first sampling voltage is used to characterize the battery voltage, and the first reference voltage > the second first reference sub-voltage > the second second reference sub-voltage > ... > the second nth reference sub-voltage. The first reference voltage corresponds to the first threshold voltage, and the second nth reference sub-voltage corresponds to the second threshold voltage. The first over-discharge protection unit is used to compare the magnitude of the first sampling voltage with the first reference voltage, and the n over-discharge protection sub-units are used to compare the magnitude of the first sampling voltage with the corresponding reference sub-voltage.

[0012] Specifically, when the first sampling voltage is less than the first reference voltage and greater than or equal to the second first reference sub-voltage, the main control unit controls the duty cycle of the main switch unit to be D1; when the first sampling voltage is less than the second first reference sub-voltage and greater than or equal to the second second reference sub-voltage, the main control unit controls the duty cycle of the main switch unit to be D2, ...; when the first sampling voltage is less than the second (n-2) reference sub-voltage and greater than or equal to the second (n-1) reference sub-voltage, the main control unit controls the duty cycle of the main switch unit to be D(n-1); when the first sampling voltage is less than the second (n-1) reference sub-voltage and greater than or equal to the second n reference sub-voltage, the main control unit controls the duty cycle of the main switch unit to be Dn; and when the first sampling voltage is less than the second n reference sub-voltage, the main control unit controls the main switch unit to be normally open, where 1 > D1 > D2 > ... > Dn > 0.

[0013] Optionally, the over-discharge protection module includes a first over-discharge protection unit and n over-discharge protection sub-units, where n is an integer greater than or equal to 2. The input terminal of the first over-discharge protection unit is connected to a first sampling voltage and a first reference voltage. The input terminals of the n over-discharge protection sub-units are respectively connected to a second first sampling sub-voltage, a second second sampling sub-voltage, ..., a second nth sampling sub-voltage, and a first reference voltage. The first sampling voltage, the second first sampling sub-voltage, the second second sampling voltage, ..., the second nth sampling sub-voltage are all used to characterize the battery voltage. The first sampling voltage < the second first sampling sub-voltage < the second second sampling voltage < ... < the second nth sampling sub-voltage. The first over-discharge protection unit is used to compare the magnitude of the first sampling voltage with the first reference voltage, and the n over-discharge protection sub-units are used to compare the magnitude of the first reference voltage with the corresponding sampling sub-voltage.

[0014] Wherein, when the first reference voltage is greater than the first sampling sub-voltage and less than or equal to the second sampling sub-voltage, the main control unit controls the duty cycle of the main switch unit to be D1; when the first reference voltage is greater than the second sampling sub-voltage and less than or equal to the second sampling sub-voltage, the main control unit controls the duty cycle of the main switch unit to be D2, ...; when the first reference voltage is greater than the second (n-2) sampling sub-voltage and less than or equal to the second (n-1) sampling sub-voltage, the main control unit controls the duty cycle of the main switch unit to be D(n-1); when the first reference voltage is greater than the second (n-1) sampling sub-voltage and less than or equal to the nth sampling sub-voltage, the main control unit controls the duty cycle of the main switch unit to be Dn; when the first reference voltage is greater than the nth sampling sub-voltage, the main control unit controls the main switch unit to be normally open, wherein 1 > D1 > D2 > ... > Dn > 0.

[0015] Optionally, the battery protection unit further includes an overcurrent protection module, whose first input terminal is connected to a third sampling voltage, whose second input terminal is connected to a third current threshold, and whose output terminal is connected to the main control unit. When the third sampling voltage is greater than or equal to the third current threshold and lasts for a third delay, the main control unit controls the main switch unit to disconnect and cut off. The third sampling voltage is used to characterize the current flowing through the main switch unit.

[0016] Among them, the third delay duration decreases step by step as the duty cycle of the main switch unit decreases.

[0017] Optionally, the battery protection circuit further includes a battery voltage sampling unit, which is connected to the positive terminal and the negative terminal of the battery. The battery voltage sampling unit is used to sample the battery voltage to obtain a first sampling voltage. The over-discharge protection module is connected to the first sampling voltage. The over-discharge protection module is also connected to a first reference voltage and a second reference voltage, wherein the second reference voltage is less than the first reference voltage.

[0018] Specifically, when the over-discharge protection module determines that the first sampling voltage is greater than or equal to the first reference voltage, the main control unit controls the main switch unit to turn on; when the over-discharge protection module determines that the first sampling voltage is less than the first reference voltage but greater than or equal to the second reference voltage, the main control unit controls the main switch unit to turn on intermittently; and when the over-discharge protection module determines that the first sampling voltage is less than the second reference voltage, the main control unit controls the main switch unit to turn off.

[0019] Optionally, the battery protection circuit further includes a battery voltage sampling unit, which is connected to the positive terminal and the negative terminal of the battery. The battery voltage sampling unit is used to sample the battery voltage to obtain a first sampling voltage and a second sampling voltage. The first sampling voltage and the second sampling voltage are both used to characterize the same battery voltage. The first sampling voltage is less than the second sampling voltage. The over-discharge protection module is connected to the first sampling voltage and the second sampling voltage. The over-discharge protection module is also connected to a first reference voltage.

[0020] Specifically, when the over-discharge protection module determines that the first sampling voltage is greater than or equal to the first reference voltage, the main control unit controls the main switch unit to turn on. When the over-discharge protection module determines that the first sampling voltage is less than the first reference voltage and the second sampling voltage is greater than or equal to the first reference voltage, the main control unit controls the main switch unit to turn on intermittently. When the second sampling voltage is less than the first reference voltage, the main control unit controls the main switch unit to turn off.

[0021] Optionally, the battery protection circuit further includes a boost unit connected in series with the system circuit. The first end of the boost unit is connected to the positive terminal of the battery, and the second end of the boost unit is connected to the system circuit. The boost unit is used to boost the voltage of the battery when it is low. The boost unit is connected to the main control unit to control whether the boost unit performs the boost.

[0022] Optionally, the control terminal of the boost unit is connected to the main control unit, and the battery protection circuit further includes a voltage judgment unit, the first input terminal of which is connected to the battery voltage, and its output terminal is connected to the main control unit;

[0023] Specifically, when the battery voltage is greater than or equal to a preset fifth threshold voltage, the main control unit controls the boost unit to enable it to save energy; when the battery voltage is less than the fifth threshold voltage, the main control unit controls the boost unit to enable it to boost the battery voltage.

[0024] The fifth threshold voltage is between the first threshold voltage and the second threshold voltage.

[0025] Optionally, the battery protection circuit is located on the same chip; or,

[0026] The battery protection circuit, excluding the main switch unit, is located on the first chip, while the main switch unit is located on the second chip.

[0027] A second aspect of this application provides a battery assembly, including:

[0028] Battery;

[0029] The battery protection circuit described above is connected to the battery.

[0030] A third aspect of this application provides an electronic device, comprising:

[0031] The system circuit includes a main load and an auxiliary load connected in parallel;

[0032] The aforementioned battery protection circuit or the aforementioned battery assembly.

[0033] Optionally, the auxiliary load includes a remote positioning module.

[0034] In this embodiment, when the battery voltage is between the first and second threshold voltages, the main switch unit is intermittently turned on, and the auxiliary and main loads are intermittently powered. When the battery voltage is below the second threshold voltage, the main control unit stops powering both the main and auxiliary loads. This design reduces system power consumption, as the battery voltage takes longer to drop from the first to the second threshold voltage. During this longer period, the auxiliary load can respond to user location tracking, facilitating location information and reducing user anxiety, thus improving user experience and safety, especially for parents locating their children via electronic devices. Furthermore, the intermittent power supply to the main and auxiliary loads within this voltage range reduces the likelihood of the electronic device not charging, minimizing overall battery damage. Additionally, this embodiment requires minimal modification to the battery protection circuit, reducing costs. When the battery voltage is below the second threshold voltage, allowing the battery to continue discharging into the system circuit would cause significant damage. Therefore, discharging into the system circuit is prohibited at this point. Thus, the design of this application balances user experience, safety, cost reduction, and minimizing battery damage. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of this application 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 application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1a This is a circuit block diagram of the electronic device according to the first embodiment of this application;

[0037] Figure 1b This is a circuit block diagram of an electronic device according to another embodiment of this application;

[0038] Figure 2 This is a circuit block diagram of the battery protection circuit according to the first embodiment of this application;

[0039] Figure 3 This is a circuit block diagram of a battery protection circuit according to another embodiment of this application;

[0040] Figure 4This is a circuit block diagram of the battery protection circuit including the boost unit according to the first embodiment of this application;

[0041] Figure 5 yes Figure 4 Detailed circuit module diagram;

[0042] Figure 6 This is a circuit block diagram of the battery protection circuit according to the second embodiment of this application;

[0043] Figure 7 This is a detailed circuit block diagram of another battery protection circuit according to the second embodiment of this application. Detailed Implementation

[0044] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0045] The terms "comprising" and "having," and any variations thereof, appearing in this application specification, claims, and drawings, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or modules is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or devices. Furthermore, the terms "first," "second," and "third," etc., are used to distinguish different objects and are not used to describe a specific order. Connections in this application include direct connections and indirect connections. An indirect connection refers to the presence of other electronic components, pins, etc., between the two connected components. The XX pin mentioned in this application may or may not be an actual pin, such as simply a pin of a component or a pin of a wire. The mention of "and / or including" in this application includes three cases, such as A and / or B, including A, B, and A and B.

[0046] First Embodiment

[0047] This application provides an electronic device, such as a smartwatch, mobile phone, tablet computer, or other consumer electronics. Please see [link to relevant documentation]. Figure 1a The electronic device includes a battery 100, a battery protection circuit 200, and a system circuit 300. The system circuit 300 is electrically connected to the battery 100 via the battery protection circuit 200, and the battery 100 is used to supply power to the system circuit 300.

[0048] In this embodiment, the system circuit 300 includes a main load 310 and an auxiliary load 320. The main load 310 is the primary load required for the operation of the electronic device. For example, the main load 310 includes a processor, a display module, an audio processing module, a camera processing module, and a memory. The auxiliary load 320 includes a remote positioning module, which includes Global Navigation Satellite System (GNSS) communication. The GNSS system may include at least one of the Global Positioning System (GPS), GLONASS, BeiDou, and Galileo. During normal operation, the current required by the main load 310 is much greater than that required by the auxiliary load 320, meaning that the power consumption of the main load 310 is much greater than that of the auxiliary load 320. For example, during normal operation, the ratio of the power consumption of the main load 310 to that of the auxiliary load 320 is greater than or equal to 5, such as a ratio of 5, 6, 7, 8, 9, 10, 20, 30, 40, 50, or 100.

[0049] In this embodiment, the battery protection circuit 200 is electrically connected to the positive and negative terminals of the battery 100, the system circuit 300 is electrically connected to the battery protection circuit 200, the battery 100 supplies power to the battery protection circuit 200, and the battery protection circuit 200 protects the battery 100, for example, when the battery 100 is overcharged, over-discharged, overcharged, or over-discharged. In this embodiment, the number of batteries 100 is one or more, preferably one. When there are multiple batteries 100, they can be connected in parallel, in series, or in a combination of series and parallel connections. The battery 100 is preferably a lithium battery 100, and the capacity of the battery 100 is, for example, 1000mAh-15000mAh, such as 1000mAh, 2000mAh, 3000mAh, 4000mAh, 5000mAh, 6000mAh, 7000mAh, 8000mAh, 9000mAh, 10000mAh, 11000mAh, 12000mAh, 13000mAh, 14000mAh, 15000mAh, etc.

[0050] Please continue reading Figure 1a In this embodiment, the battery protection circuit 200 includes a power supply terminal VDD, a power ground terminal GND, a battery protection unit, a main control unit 230, and a main switch unit M0.

[0051] In this embodiment, the power supply terminal VDD and the power ground terminal GND are used to connect to the positive and negative terminals of the battery 100, so that the battery 100 can supply power to the battery protection circuit 200. At the same time, the battery 100 forms a loop through the battery protection circuit 200 and the system circuit 300 to supply power to the system circuit 300.

[0052] In this embodiment, the first terminal of the main switch unit M0 is connected to the positive terminal of the battery 100 via the power supply terminal VDD, and the second terminal of the main switch unit M0 is connected to the first terminal of the main load 310 and the first terminal of the auxiliary load 320 via the system terminal VM. The second terminals of the main load 310 and the auxiliary load 320 are both connected to the negative terminal of the battery 100. Figure 1a However, this application is not limited to this; for other embodiments of this application, please refer to [link / reference needed]. Figure 1b The first terminal of the main load 310 and the first terminal of the auxiliary load 320 are both connected to the positive terminal of the battery 100. The second terminals of the main load 310 and the auxiliary load 320 are both connected to the first terminal of the main switch unit M0 via the system terminal VM. The second terminal of the main switch unit M0 is connected to the negative terminal of the battery 100 via the power ground terminal GND. That is, the positions of the main switch unit M0 and the main load 310 and auxiliary load 320 are interchanged. Thus, the main switch unit M0 can control whether the battery 100 supplies power to the main load 310 and the auxiliary load 320.

[0053] In this embodiment, the control terminal of the main switch unit M0 is connected to the main control unit 230, which controls the main switch unit M0 to turn on or off. In this embodiment, when the main switch unit M0 is on, the battery 100 supplies power to the main load 310 and the auxiliary load 320, both of which operate, and the electronic device functions normally. When the main switch unit M0 is off, the battery 100 stops supplying power to the main load 310 and the auxiliary load 320, and both the main load 310 and the auxiliary load 320 cease operation; at this time, the electronic device does not operate.

[0054] To prevent damage to battery 100 due to excessively low battery voltage, the battery protection circuit 200 in this embodiment incorporates over-discharge protection. The battery protection unit includes an over-discharge protection module 400, whose input is connected to the battery voltage (the current voltage of battery 100), and whose output is connected to the main control unit 230. In this embodiment, the over-discharge protection module 400 compares the battery voltage with a threshold voltage to determine if the battery voltage is too low. Specifically, the over-discharge protection module 400 compares the battery voltage with preset first and second threshold voltages for subsequent processing, wherein the first threshold voltage is greater than the second threshold voltage. In this embodiment, for ease of description, the magnitudes of the first and second threshold voltages are relative to the battery voltage.

[0055] In this embodiment, when the over-discharge protection module 400 determines that the battery voltage is greater than or equal to the first threshold voltage, the over-discharge protection module 400 outputs a normal discharge signal to the main control unit 230. The main control unit 230 controls the main switch unit M0 to conduct normally, that is, to be constantly conducting, so that the battery 100 normally supplies power to the main load 310 and the auxiliary load 320, and the main load 310 and the auxiliary load 320 work normally.

[0056] To ensure the electronic device can still be located even when the battery voltage is low, and to protect the battery 100, in this embodiment, when the over-discharge protection module 400 determines that the battery voltage is less than the first threshold voltage and greater than or equal to the second threshold voltage, the over-discharge protection module 400 outputs a first over-discharge protection signal to the main control unit 230. Compared with the prior art, in this embodiment, the main control unit 230 does not control the main switch unit M0 to be completely turned off. The main control unit 230 controls the main switch unit M0 to be turned on intermittently, for example, controlling the duty cycle of the main switch unit M0 to be constant at 90%, 85%, 80%, 70%, 60%, 50%, 40%, 30%, etc., so that when the main switch unit M0 is turned on, the battery 100 normally supplies power to the main load 310 and the auxiliary load 320, and the auxiliary load 320 works normally, so the electronic device can be located normally. When the switch unit M0 is turned off, the battery 100 stops supplying power to the main load 310 and the auxiliary load 320, thereby saving energy. When the over-discharge protection module 400 determines that the battery voltage is lower than the second threshold voltage, it considers the battery voltage to be very low and requires further action. At this time, the over-discharge protection module outputs a second over-discharge protection signal to the main control unit 230. The main control unit 230 controls the main switch unit M0 to remain open (normally open). In this case, the battery 100 does not supply power to the main load 310 or the auxiliary load 320. In this embodiment, the second threshold voltage is lower than the first threshold voltage. For example, the first threshold voltage is 2.9V, 3V, 3.1V, etc., and the second threshold voltage is 2V, 2.1V, 2.2V, etc. In this embodiment, the main control unit 230 controls the main switch unit M0 to be intermittently turned on, with a duty cycle of, for example, 90%-30%, such as 90%, 80%, 70%, 60%, 50%, 40%, 30%.

[0057] In this embodiment, when the battery voltage is between the first threshold voltage and the second threshold voltage, the main switch unit M0 is intermittently turned on, and the auxiliary load 320 and the main load 310 are intermittently powered. When the battery voltage is less than the second threshold voltage, the main control unit 230 controls the main load 310 and the auxiliary load 320 to be de-powered. With this configuration, when the battery voltage is between the first and second threshold voltages, the main switch unit M0 is intermittently turned on, thus the main load 310 and the auxiliary load 320 are intermittently powered by the battery. This design helps reduce the power consumption of the system circuit 300, as it takes a longer time for the battery voltage to drop from the first threshold voltage to the second threshold voltage. During this longer time, the auxiliary load 320, while powered, can respond to the user's location, facilitating the acquisition of the user's location information, thereby reducing user anxiety, greatly improving the user experience, and enhancing user safety. It is especially beneficial for parents to locate their children using electronic devices. Furthermore, because the main load 310 and auxiliary load 320 are intermittently powered within this voltage range, the time required for the battery voltage to drop to the second threshold voltage is relatively long, for example, exceeding 5 days. During this range, the probability of the electronic device not being charged is low, thus minimizing overall damage to the battery 100. Additionally, the design of this embodiment requires minimal modification to the battery protection circuit, which helps reduce costs. When the battery voltage is below the second threshold voltage, allowing the battery 100 to continue discharging into the system circuit 300 would cause significant damage to the battery 100; therefore, discharging into the system circuit 300 by the battery 100 is prohibited at this time. Thus, through the design of this application, user experience, safety, cost reduction, and reduced damage to the battery 100 can be balanced.

[0058] In the actual design of the battery protection circuit 200, the battery voltage is generally not obtained directly. In actual design, the comparison between the battery voltage and the threshold voltage is generally carried out using the following two methods, which are described below:

[0059] 1. Please see Figure 2(This embodiment is described using this as an example.) The battery protection circuit 200 includes a battery voltage sampling unit 210. One end of the battery voltage sampling unit 210 is connected to the power supply terminal VDD, and the other end is connected to the power ground terminal GND. With this configuration, a first sampling voltage can be detected. The first sampling voltage characterizes the battery voltage; that is, the first sampling voltage corresponds to the battery voltage, and the two are positively linearly correlated. Specifically, the battery voltage sampling unit 210 includes a first resistor R1 and a second resistor R2, which are connected in series. The first resistor R1 is connected to the power supply terminal VDD, and the second resistor R2 is connected to the power ground terminal GND. The voltage at the point where the second resistor R2 is connected to the first resistor R1 is the first sampling voltage, which is then transmitted to the over-discharge protection module 400. Only one sampling voltage needs to be designed here, making the sampling implementation simple and straightforward.

[0060] Here, the over-discharge protection module 400 includes a first over-discharge protection unit 410 and a second over-discharge protection unit 420. The input terminals of the first over-discharge protection unit 410 are respectively connected to a first sampling voltage and a preset first reference voltage Vref1, and its output terminal is connected to the main control unit 230. The input terminals of the second over-discharge protection unit 420 are respectively connected to the first sampling voltage and a preset second reference voltage Vref2, and its output terminal is connected to the main control unit 230. The first reference voltage Vref1 corresponds to a first threshold voltage, and the second reference voltage Vref2 corresponds to a second threshold voltage. The first reference voltage Vref1 is greater than the second reference voltage Vref2. In this embodiment, the first over-discharge protection unit 410 includes a first voltage comparator, and the second over-discharge protection unit 420 includes a second voltage comparator. When the first sampling voltage is greater than or equal to the first reference voltage Vref1, both the first over-discharge protection unit 410 and the second over-discharge protection unit 420 output normal signals to the main control unit 230, meaning the two normal signals constitute a normal discharge signal. When the first sampling voltage is less than the first reference voltage Vref1 and greater than or equal to the second reference voltage Vref2, the first over-discharge protection unit 410 outputs an over-discharge signal to the main control unit 230, and the second over-discharge protection unit 420 outputs a normal signal to the main control unit 230, meaning the over-discharge signal output by the first over-discharge protection unit 410 and the normal signal output by the second over-discharge protection unit 420 together constitute the first over-discharge protection signal. When the first sampling voltage is less than the second reference voltage Vref2, both the first over-discharge protection unit 410 and the second over-discharge protection unit 420 output over-discharge signals to the main control unit 230, meaning the over-discharge signal output by the first over-discharge protection unit 410 and the over-discharge signal output by the second over-discharge protection unit 420 together constitute the second over-discharge protection signal.

[0061] 2. Please see Figure 3The battery protection circuit 200 includes a battery voltage sampling unit 210. One end of the battery voltage sampling unit 210 is connected to the power supply terminal VDD, and the other end is connected to the power supply ground terminal GND. This configuration allows for the detection of a first sampling voltage and a second sampling voltage. These two voltages characterize the same battery voltage; that is, both the first and second sampling voltages correspond to the battery voltage and are positively linearly correlated with it. Specifically, the battery voltage sampling unit 210 includes a first resistor R1, a second resistor R2, and a third resistor R3, connected in series. The first resistor R1 is connected to the power supply ground terminal GND, and the third resistor R3 is connected to the power supply terminal VDD. The voltage at the point where the second resistor R2 is connected to the first resistor R1 is the first sampling voltage, and the voltage at the point where the third resistor R3 is connected to the second resistor R2 is the second sampling voltage. Both the first and second sampling voltages are transmitted to the over-discharge protection module 400. Here, for the same battery voltage, the second sampling voltage is greater than the first sampling voltage.

[0062] Here, the over-discharge protection module 400 includes a first over-discharge protection unit 410 and a second over-discharge protection unit 420. The input terminals of the first over-discharge protection unit 410 are respectively connected to a first sampling voltage and a preset first reference voltage Vref1, and its output terminal is connected to the main control unit 230. The input terminals of the second over-discharge protection unit 420 are respectively connected to a second sampling voltage and the first reference voltage Vref1, and its output terminal is connected to the main control unit 230. The comparison between the first sampling voltage and the first reference voltage Vref1 corresponds to the comparison between the battery voltage and a first threshold voltage, and the comparison between the second sampling voltage and the first reference voltage Vref1 corresponds to the comparison between the battery voltage and a second threshold voltage. In this embodiment, the first over-discharge protection unit 410 includes a first voltage comparator, and the second over-discharge protection unit 420 includes a second voltage comparator. When the first sampling voltage is greater than or equal to the first reference voltage Vref1, both the first over-discharge protection unit 410 and the second over-discharge protection unit 420 output normal signals to the main control unit 230, meaning the two normal signals constitute a normal discharge signal. When the first sampling voltage is less than the first reference voltage Vref1 and the second reference voltage Vref2 is greater than or equal to the first reference voltage Vref1, the first over-discharge protection unit 410 outputs an over-discharge signal to the main control unit 230, and the second over-discharge protection unit 420 outputs a normal signal to the main control unit 230, meaning the over-discharge signal output by the first over-discharge protection unit 410 and the normal signal output by the second over-discharge protection unit 420 together constitute the first over-discharge protection signal. When the second sampling voltage is less than the first reference voltage Vref1, both the first over-discharge protection unit 410 and the second over-discharge protection unit 420 output over-discharge signals to the main control unit 230, meaning the over-discharge signal output by the first over-discharge protection unit 410 and the over-discharge signal output by the second over-discharge protection unit 420 together constitute the second over-discharge protection signal. Only a reference voltage needs to be designed here, and the design of the reference voltage is relatively simple.

[0063] In addition, in other embodiments of this application, a first sampling voltage, a second sampling voltage, a first reference voltage Vref1, and a second reference voltage Vref2 can be designed. The first sampling voltage is compared with the first reference voltage Vref1, which corresponds to the comparison between the battery voltage and the first threshold voltage. The second sampling voltage is compared with the second reference voltage Vref2, which corresponds to the comparison between the battery voltage and the second threshold voltage. The principle of comparison is similar to that described in 1 and 2 above, which is easy for those skilled in the art to understand, and will not be repeated here.

[0064] Generally speaking, as the battery voltage decreases, the main load 310 and auxiliary load 320 require a certain voltage to operate. In particular, a decrease in battery voltage may prevent the auxiliary load 320 from operating, leading to ineffective positioning when the battery voltage drops to a certain level. To improve this issue, please refer to [reference needed]. Figure 1a and Figure 4 In this embodiment, the battery protection circuit 200 further includes a boost unit 240. One end of the boost unit 240 is connected to the positive terminal of the battery 100 via the main switching unit M0, and the other end of the boost unit 240 is connected to one end of the system circuit 300. The other end of the system circuit 300 is connected to the negative terminal of the battery 100. With this configuration, when the battery voltage is low, the boost unit 240 boosts the voltage, increasing the voltage output to the auxiliary load 320 and the main load 310, thereby enabling the auxiliary load 320 to operate normally. In this embodiment, the boost unit 240 is, for example, a charge pump (…). Figure 5 (This will be used as an example for illustration), boost voltage, etc., which will not be elaborated on here.

[0065] To save power, please refer to [link / reference]. Figure 1a , Figure 4 and Figure 5 In this embodiment, the boost unit 240 is not always operational. To achieve this, the battery protection circuit 200 further includes a voltage judgment unit 250. The first input terminal of the voltage judgment unit 250 is used to input the battery voltage, its second input terminal is used to input a preset fifth threshold voltage, and its output terminal is connected to the main control unit 230. The main control unit 230 is also connected to the enable terminal of the boost unit 240. When the battery voltage is greater than or equal to the fifth threshold voltage, the main control unit 230 controls the boost unit 240 to enable. At this time, the boost unit 240 does not boost the battery voltage; the battery voltage is directly supplied to the auxiliary load 320, which can then function normally. When the battery voltage is less than the fifth threshold voltage, the main control unit 230 controls the boost unit 240 to enable, thereby boosting the battery voltage before supplying it to the auxiliary load 320. In this embodiment, the boost voltage boosted by the boost unit 240 is, for example, 1.5 times, 2 times, 2.5 times, or 3 times the battery voltage. This embodiment combines the voltage judgment unit 250 with the boost unit 240, which improves the flexibility of the boost unit 240 and further saves power. In this embodiment, the fifth threshold voltage is located between the first threshold voltage and the second threshold voltage, for example, the fifth threshold voltage is 2.5V, 2.4V, etc. In this embodiment, the voltage judgment unit 250 includes a voltage comparator. In this embodiment, the boost unit 240 is located inside the battery protection circuit 200, and the control of the boost unit 240 is relatively flexible. To compare the battery voltage with the fifth threshold voltage, the figure shows a design that compares the first sampling voltage with the fifth reference voltage Vref5.

[0066] Figure 5The diagram illustrates a detailed view of a charge pump boost unit 240. In the diagram, the boost unit 240 includes a fifth switch K5, a sixth switch K6, a seventh switch K7, and a first capacitor C1. The specific connections of these components are shown in the diagram and will not be described further here. In this embodiment, when the main control unit 230 controls the boost unit 240 to be enabled, the main control unit 230 keeps the fifth switch K5 and the seventh switch K7 on and keeps the sixth switch K6 off. At this time, the battery voltage directly supplies power to the system circuit 300. When the main control unit 230 controls the boost unit 240 to be enabled, the main control unit 230 controls the boost unit 240 at certain intervals. One interval includes a first time period and a second time period. During the first time period, the main control unit controls the fifth switch K5 and the seventh switch K7 to be on and keeps the sixth switch K6 off. During the second time period, the main control unit controls the fifth switch K5 and the seventh switch K7 to be off and keeps the sixth switch K6 on. This achieves voltage boosting, ensuring that the voltage output to the system circuit 300 is greater than the battery voltage. The specific boost principle is a conventional technology in this field and will not be elaborated here.

[0067] Please refer to the above. Figures 1a-5 In this embodiment, one end of the main switch unit M0 is connected to the positive terminal of the battery 100 via the power supply terminal VDD or the power ground terminal GND. Figure 1a ) or negative electrode ( Figure 1bThe main switch unit M0 is connected to the main load 310 and the auxiliary load 320 via the system terminal VM. The control terminal of the main switch unit M0 is connected to the main control unit 230. The main control unit 230 controls the main switch unit M0 to turn on or off, thereby controlling the battery 100 to supply power to or stop supplying power to the main load 310 and the auxiliary load 320. In this embodiment, the main switch unit M0 includes a charging switch and a discharging switch, which are connected in series. Both the charging switch and the discharging switch are MOSFETs or transistors, etc. The control terminals of the charging switch and the discharging switch are electrically connected to the main control unit 230, so that the main control unit 230 can control the charging switch and the discharging switch to turn on or off respectively. When the main control unit 230 controls the battery 100 to stop supplying power to the system circuit 300, the main control unit 230 controls the discharging switch to turn off. However, this application is not limited to this. In other embodiments of this application, the main switching unit M0 includes a first switching transistor, and the battery protection circuit 200 includes a substrate switching control unit. The first switching transistor is a MOSFET, and its control terminal is electrically connected to the main control unit 230. The substrate switching control unit is also electrically connected to the main control unit 230. The substrate switching control unit is used to correctly bias the substrate of the first switching transistor. Furthermore, in other embodiments of this application, the main switching unit M0 can also be implemented in other ways, such as including only one switching transistor. In this embodiment, the main switching unit M0 is used to control the battery 100 to supply power to the main load 310 and the auxiliary load 320. Specifically, a circuit is formed between the battery 100, the main switching unit M0 of the battery protection circuit 200, the main load 310, and the auxiliary load 320 to supply power to the main load 310 and the auxiliary load 320.

[0068] In this embodiment, the battery protection circuit 200 is located on the same integrated circuit chip. In other embodiments of this application, the battery protection circuit 200, except for the main switch unit M0, is located on the first integrated circuit chip, and the main switch unit M0 is located on the second integrated circuit chip; the two chips are packaged together.

[0069] In this embodiment, when the battery voltage is between the first threshold voltage and the second threshold voltage, the main control unit 230 controls the main switch unit M0 to be continuously turned on. This process can improve the standby time of the auxiliary load 320. However, further improving the standby time of the auxiliary load 320 is a continuous effort. In order to further improve the standby time of the auxiliary load 320 and improve the user experience, this application provides a second embodiment.

[0070] Second Embodiment

[0071] Please see Figure 6 , Figure 6 This is a partial circuit block diagram of the battery protection circuit 200 according to the second embodiment of this application. This embodiment is similar to the first embodiment. Therefore, the parts not described in this embodiment can be referred to the first embodiment. The main difference between this embodiment and the first embodiment is that the duty cycle of the main switch unit M0 decreases step by step as the battery voltage decreases.

[0072] To further reduce power consumption, improve standby time, and minimize damage to the battery 100, in this embodiment, the duty cycle of the main switching unit M0 decreases gradually as the battery voltage decreases, for example, from 90% to 30%. Specifically, please refer to [reference needed]. Figure 1a and Figure 6 In this embodiment, the second over-discharge protection unit 420 includes n over-discharge protection sub-units, where n is an integer greater than or equal to 2. The n over-discharge protection sub-units are the second first over-discharge protection sub-unit 421, the second second over-discharge protection sub-unit 422, ..., the second nth over-discharge protection sub-unit 42n. Correspondingly, n reference sub-voltages are also set, which are the second first reference sub-voltage Vref21, the second second reference sub-voltage Vref22, ..., the second nth reference sub-voltage Vref2n, where the second first reference sub-voltage Vref21 > the second second reference voltage Vref22 > ... > the second nth reference voltage Vref2n, and the second nth reference voltage Vref2n is the second reference voltage Vref2. In this embodiment, the first input terminal of the second over-discharge protection subunit 421, the first input terminal of the second over-discharge protection subunit 422, ..., the first input terminal of the second n over-discharge protection subunit 42n are all connected to the first sampling voltage. The second input terminal of the second over-discharge protection subunit 421 is connected to the second first reference sub-voltage Vref21, the second input terminal of the second second over-discharge protection subunit 422 is connected to the second second reference sub-voltage Vref22, ..., the second input terminal of the second n over-discharge protection subunit 42n is connected to the second n reference sub-voltage Vref2n. Thus, the first reference voltage Vref1 and the second reference voltage Vref2 are divided into n segments by n over-discharge protection subunits and n reference sub-voltages. The n segments correspond to different duty cycles, and the duty cycle becomes smaller and smaller as the first sampling voltage decreases. Correspondingly, the n duty cycles are D1, D2, ..., Dn, and 1 > D1 ≥ D2 ≥ ... ≥ Dn > 0, and D1 > Dn.

[0073] Please continue reading Figure 1a and Figure 6In this embodiment, when the first sampling voltage is less than the first reference voltage Vref1 and greater than or equal to the second reference sub-voltage Vref21, the first over-discharge protection unit 410 outputs an over-discharge signal to the main control unit 230, and the second over-discharge protection sub-units 421 to 42n all output normal signals to the main control unit 230. At this time, the main control unit 230 receives the first over-discharge protection signal and controls the duty cycle of the main switching unit M0 to be D1; when the first sampling voltage is less than the second reference sub-voltage Vref21 and greater than or equal to the second reference sub-voltage Vref22, the first over-discharge protection unit 410 outputs an over-discharge signal to the main control unit 230. Over-discharge protection unit 410 and the second over-discharge protection subunit 421 both output over-discharge signals to the main control unit 230, while other over-discharge protection subunits output normal signals to the main control unit 230. At this time, the main control unit 230 receives the first and second over-discharge protection signals and controls the duty cycle of the main switch unit M0 to D2;...; When the first sampling voltage is less than the second (n-2) reference sub-voltage and greater than or equal to the second (n-1) reference sub-voltage, the first over-discharge protection unit 410, the second over-discharge protection subunit 421, the second over-discharge protection subunit 422,..., and the second (n-2) over-discharge protection subunit all output over-discharge signals. The signal is sent to the main control unit 230. The second (n-1) over-discharge protection subunit and the second n over-discharge protection subunit 42n both output normal signals to the main control unit 230. At this time, the main control unit 230 receives the first (n-1) over-discharge protection signal and controls the duty cycle of the main switch unit M0 to D(n-1). When the first sampled voltage is less than the second (n-1) reference sub-voltage and greater than or equal to the second n reference sub-voltage Vref2n, the second first over-discharge protection subunit 421, the second second over-discharge protection subunit 422, ..., the second (n-1) over-discharge protection subunit all output over-discharge signals to the main control unit 230. The second n over-discharge protection subunit 42n outputs a normal signal to the main control unit 230. At this time, the main control unit 230 receives the first n over-discharge protection signal and controls the duty cycle of the main switch unit M0 to Dn. When the first sampling voltage is less than the second n reference voltage Vref2n, the first over-discharge protection unit 410, the second first over-discharge protection subunit 421, the second second over-discharge protection subunit 422, ..., the second n over-discharge protection subunit 42n all output over-discharge signals to the main control unit 230. At this time, the main control unit 230 receives the second over-discharge protection signal and controls the main switch unit M0 to disconnect.

[0074] Preferably, the duty cycle of the main switch unit M0 is D1 > D2 > ... > Dn. This setting further reduces power consumption, increases the standby time of the auxiliary load 320 and the main load 310, reduces damage to the battery 100, and facilitates convenient positioning when needed. However, this application is not limited to this. In other embodiments of this application, D1 ≥ D2 ≥ ... ≥ Dk > D(k+1) ≥ ... ≥ Dn, where k is an integer greater than 1 and less than n, and D1 > Dn, for example, D1 is 90% and Dn is 30%.

[0075] Additionally, in other embodiments of this application, please refer to [reference needed]. Figure 1a and Figure 7 The second over-discharge protection unit 420 includes n over-discharge protection sub-units, where n is an integer greater than or equal to 2. The n over-discharge protection sub-units are the second first over-discharge protection sub-unit 421, the second second over-discharge protection sub-unit 422, ..., the second nth over-discharge protection sub-unit 42n. Correspondingly, the third resistor R3 of the battery voltage sampling unit 210 includes a third first sub-resistor R31, a third second sub-resistor R32, ..., a third nth sub-resistor R3n. The first resistor R1, the second resistor R2, the third first sub-resistor R31, the third second sub-resistor R32, ..., the third nth sub-resistor R3n are connected in series. One end of the first resistor R1 is connected to the power ground terminal GND, and one end of the third nth sub-resistor R3n is connected to the power supply terminal VDD. The lower end of the second resistor R2... The voltage is the first sampling voltage. The voltage at the lower end of the third sub-resistor R31 is the second sampling sub-voltage. The voltage at the lower end of the third sub-resistor R32 is the second sampling sub-voltage, ..., the voltage at the lower end of the third n sub-resistor R3n is the second n sampling sub-voltage. For the same battery voltage, the first sampling voltage < the second sampling sub-voltage < the second sampling sub-voltage < ... < the second n sampling sub-voltage. The second sampling sub-voltage is sent to the second over-discharge protection sub-unit 421, the second sampling sub-voltage is sent to the second over-discharge protection sub-unit 422, ..., the second n sampling sub-voltage is sent to the second n over-discharge protection sub-unit 42n. Here, all over-discharge protection sub-units share the same reference voltage, namely the first reference voltage Vref1, which helps to reduce complexity.

[0076] Here, when the first reference voltage Vref1 is greater than the first sampling sub-voltage and less than or equal to the second sampling sub-voltage, the main control unit 230 controls the duty cycle of the main switch unit M0 to D1; when the first reference voltage Vref1 is greater than the second sampling sub-voltage and less than or equal to the second sampling sub-voltage, the main control unit 230 controls the duty cycle of the main switch unit M0 to D2, ..., when the first reference voltage Vref1 is greater than the second (n-2) sampling sub-voltage and less than or equal to the second (n-1) sampling sub-voltage, the main control unit 230 controls the duty cycle of the main switch unit M0 to D(n-1); when the first reference voltage Vref1 is greater than the second (n-1) sampling sub-voltage and less than or equal to the nth sampling sub-voltage, the main control unit 230 controls the duty cycle of the main switch unit M0 to Dn; when the first reference voltage Vref1 is greater than the nth sampling sub-voltage, the main control unit 230 controls the main switch unit M0 to be normally open. Thus, the first threshold voltage and the second threshold voltage are divided into n segments by n over-discharge protection sub-units and n sampling sub-voltages. The n segments correspond to different duty cycles, and the duty cycle becomes smaller and smaller as the battery voltage decreases. Correspondingly, the n duty cycles satisfy 1>D1≥D2≥...≥Dn>0, and D1>Dn. Preferably, 1>D1>D2>...>Dn>0.

[0077] Please continue to refer to the above. Figure 1a and Figure 6 This embodiment also provides discharge overcurrent protection. Specifically, the battery protection circuit 200 further includes an overcurrent protection module 220. The overcurrent protection module 220 is used for conventional discharge overcurrent protection. The first input terminal of the overcurrent protection module 220 is connected to a third sampling voltage, its second input terminal is connected to a preset third current threshold Vref3, and its output terminal is connected to the main control unit 230. In this embodiment, the third sampling voltage is used to characterize the current flowing through the main switching unit M0, that is, to characterize the sum of the currents flowing through the main load 310 and the auxiliary load 320. In this embodiment, the third sampling voltage is the voltage on the main switching unit M0, and the third current threshold Vref3 is used for conventional overcurrent protection. In this embodiment, the overcurrent protection module 220 includes a voltage comparator and a delay unit. The delay unit has a preset third delay duration. When the overcurrent protection module 220 determines that the third sampling voltage is greater than or equal to the third current threshold Vref3 and continues for the third delay duration, the overcurrent protection module 220 outputs an overcurrent protection signal to the main control unit 230, and the main control unit 230 controls the main switching unit M0 to remain open. During the overcurrent protection judgment process, when the third sampled voltage is less than the third current threshold Vref3, the timer of the delay unit will be reset to zero. When the third sampled voltage is greater than or equal to the third current threshold Vref3 again, the delay duration will start counting from 0.

[0078] In this embodiment, the third delay duration is fixed. However, when the battery voltage is between the first threshold voltage and the second threshold voltage, as the battery voltage decreases, the duty cycle of the main switch unit M0 controlled by the main control unit 230 decreases step by step, meaning the duty cycle becomes increasingly lower. Consequently, the conduction time of the main switch unit M0 within one cycle becomes increasingly shorter. This presents a problem: the conduction time of the main switch unit M0 may be less than the third delay duration. Consequently, even if an overcurrent fault occurs in the system circuit 300, the duration for which the third sampled voltage is greater than or equal to the third current threshold Vref will not exceed the third delay duration. Therefore, the overcurrent protection module 220 may never output an overcurrent protection signal to the main control unit 230, leading to overcurrent protection failure. To improve this problem, in this embodiment, the third delay duration decreases step by step as the duty cycle of the main switch unit M0 decreases. By setting it in this way, it can be ensured that the conduction time of the main switch unit M0 within one cycle is greater than the corrected third delay duration.

[0079] To achieve a gradual decrease in the third delay duration as the duty cycle of the main switch unit M0 decreases, in this embodiment, the delay unit is connected to the main control unit 230. When the main control unit 230 controls the duty cycle of the main switch unit M0 to be D1, D2, ..., Dn, the third delay duration of the delay unit is corrected to: third delay duration * corresponding duty cycle. That is, when the duty cycle of the main switch unit M0 is controlled to be D1, the delay duration of the delay unit is corrected to: third delay duration * D1; when the duty cycle of the main switch unit M0 is controlled to be D2, the delay duration of the delay unit is corrected to: third delay duration * D2; ...; when the duty cycle of the main switch unit M0 is controlled to be Dn, the delay duration of the delay unit is corrected to: third delay duration * Dn. This application is not limited to this. In other embodiments of this application, the delay unit is connected to the main control unit 230. When the main control unit 230 controls the duty cycle of the main switch unit M0 to be D1, D2, ..., Dn, the third delay duration of the delay unit is modified to: third delay duration - j * fixed duration, where j is the subscript of D1, D2, ..., Dn, that is, j is one of 1, 2, 3, ..., n. The fixed duration is preset, that is, when the duty cycle of the main switch unit M0 is controlled to be D1, the delay duration of the delay unit is modified to: third delay duration - 1 * fixed duration; when the duty cycle of the main switch unit M0 is controlled to be D2, the delay duration of the delay unit is modified to: third delay duration - 2 * fixed duration.

[0080] When the duty cycle of the main switch unit M0 is Dn, the delay duration of the delay unit is modified to: third delay duration - n * fixed duration. This setting ensures that the conduction duration of the main switch unit M0 is greater than the delay duration within one cycle. Furthermore, those skilled in the art can also achieve a gradual decrease in the third delay duration as the duty cycle of the main switch unit M0 decreases step by step using other methods; these will not be illustrated in detail in this embodiment.

[0081] In this embodiment, as the battery voltage decreases step by step, the duty cycle of the main switch unit M0 decreases step by step. In this case, when the first sampling voltage is synchronously less than the fifth reference voltage Vref5, the boost unit 240 is only enabled when the main switch unit M0 is turned on (on time). When the main switch unit M0 is turned off (off time), the boost unit 240 is enabled. That is, the boost unit 240 needs to match whether the main switch unit M0 is turned on or off, which can accurately control the boosting and further reduce the power consumption of the boost unit 240. There will be no situation where the main switch unit M0 is turned off but the boost unit 240 is enabled, which can further reduce power consumption.

[0082] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is merely an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit. Furthermore, the specific names of the functional units and modules are only for easy differentiation and are not intended to limit the scope of protection of this application. The specific working process of the units and modules in the above system can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0083] It should be understood that "a plurality of" as used herein refers to two or more. Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the application disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this application are indicated by the following claims.

[0084] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus embodiments, since they are basically similar to the method embodiments, the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments.

[0085] The above-disclosed embodiments are merely preferred embodiments of this application and should not be construed as limiting the scope of this application. Therefore, any equivalent variations made in accordance with the claims of this application shall still fall within the scope of this application.

Claims

1. A battery protection circuit, characterized in that, include: The system includes a main control unit and a main switch unit, wherein the main control unit is connected to the control terminal of the main switch unit, the main switch unit is used to connect in series with the system circuit, and the main switch unit is used to control whether the battery supplies power to the system circuit. The system circuit includes a main load and an auxiliary load connected in parallel. The over-discharge protection module has its input terminal connected to the battery voltage and its output terminal connected to the main control unit. Specifically, when the over-discharge protection module determines that the battery voltage is greater than or equal to a preset first threshold voltage, the main control unit controls the main switch unit to conduct normally; when the over-discharge protection module determines that the battery voltage is less than the first threshold voltage but greater than or equal to a preset second threshold voltage, the main control unit controls the main switch unit to conduct intermittently; when the over-discharge protection module determines that the battery voltage is less than the second threshold voltage, the main control unit controls the main switch unit to disconnect, wherein the second threshold voltage is less than the first threshold voltage.

2. The battery protection circuit according to claim 1, characterized in that, When the battery voltage is less than the first threshold voltage and greater than or equal to the second threshold voltage, the duty cycle of the main switch unit decreases step by step as the battery voltage decreases.

3. The battery protection circuit according to claim 2, characterized in that, The over-discharge protection module includes a first over-discharge protection unit and n over-discharge protection sub-units, where n is an integer greater than or equal to 2. The input terminal of the first over-discharge protection unit is connected to a first sampling voltage and a first reference voltage. The input terminals of the n over-discharge protection sub-units are respectively connected to a first sampling voltage, a second first reference sub-voltage, a second second reference sub-voltage, ..., a second nth reference sub-voltage. The first sampling voltage is used to characterize the battery voltage, and the first reference voltage > the second first reference sub-voltage > the second second reference sub-voltage > ... > the second nth reference sub-voltage. The first reference voltage corresponds to the first threshold voltage, and the second nth reference sub-voltage corresponds to the second threshold voltage. The first over-discharge protection unit is used to compare the magnitude of the first sampling voltage with the first reference voltage, and the n over-discharge protection sub-units are used to compare the magnitude of the first sampling voltage with the corresponding reference sub-voltage. Specifically, when the first sampling voltage is less than the first reference voltage and greater than or equal to the second first reference sub-voltage, the main control unit controls the duty cycle of the main switch unit to be D1; when the first sampling voltage is less than the second first reference sub-voltage and greater than or equal to the second second reference sub-voltage, the main control unit controls the duty cycle of the main switch unit to be D2, ...; when the first sampling voltage is less than the second (n-2) reference sub-voltage and greater than or equal to the second (n-1) reference sub-voltage, the main control unit controls the duty cycle of the main switch unit to be D(n-1); when the first sampling voltage is less than the second (n-1) reference sub-voltage and greater than or equal to the second n reference sub-voltage, the main control unit controls the duty cycle of the main switch unit to be Dn; and when the first sampling voltage is less than the second n reference sub-voltage, the main control unit controls the main switch unit to be normally open, where 1 > D1 > D2 > ... > Dn > 0.

4. The battery protection circuit according to claim 2, characterized in that, The over-discharge protection module includes a first over-discharge protection unit and n over-discharge protection sub-units, where n is an integer greater than or equal to 2. The input terminal of the first over-discharge protection unit is connected to a first sampling voltage and a first reference voltage. The input terminals of the n over-discharge protection sub-units are respectively connected to a second first sampling sub-voltage, a second second sampling sub-voltage, ..., a second nth sampling sub-voltage, and a first reference voltage. The first sampling voltage, the second first sampling sub-voltage, the second second sampling voltage, ..., the second nth sampling sub-voltage are all used to characterize the battery voltage. The first sampling voltage < the second first sampling sub-voltage < the second second sampling voltage < ... < the second nth sampling voltage. The first over-discharge protection unit is used to compare the magnitude of the first sampling voltage with the first reference voltage, and the n over-discharge protection sub-units are used to compare the magnitude of the first reference voltage with the corresponding sampling sub-voltage. Wherein, when the first reference voltage is greater than the first sampling sub-voltage and less than or equal to the second sampling sub-voltage, the main control unit controls the duty cycle of the main switch unit to be D1; when the first reference voltage is greater than the second sampling sub-voltage and less than or equal to the second sampling sub-voltage, the main control unit controls the duty cycle of the main switch unit to be D2, ...; when the first reference voltage is greater than the second (n-2) sampling sub-voltage and less than or equal to the second (n-1) sampling sub-voltage, the main control unit controls the duty cycle of the main switch unit to be D(n-1); when the first reference voltage is greater than the second (n-1) sampling sub-voltage and less than or equal to the nth sampling sub-voltage, the main control unit controls the duty cycle of the main switch unit to be Dn; when the first reference voltage is greater than the nth sampling sub-voltage, the main control unit controls the main switch unit to be normally open, wherein 1 > D1 > D2 > ... > Dn > 0.

5. The battery protection circuit according to claim 2, characterized in that, The battery protection unit also includes an overcurrent protection module, whose first input terminal is connected to a third sampling voltage, whose second input terminal is connected to a third current threshold, and whose output terminal is connected to the main control unit. When the third sampling voltage is greater than or equal to the third current threshold and lasts for a third delay, the main control unit controls the main switch unit to open and close. The third sampling voltage is used to characterize the current flowing through the main switch unit. Among them, the third delay duration decreases step by step as the duty cycle of the main switch unit decreases.

6. The battery protection circuit according to claim 1, characterized in that, The battery protection circuit further includes a battery voltage sampling unit, which is connected to the positive terminal and the negative terminal of the battery. The battery voltage sampling unit is used to sample the battery voltage to obtain a first sampling voltage. The over-discharge protection module is connected to the first sampling voltage. The over-discharge protection module is also connected to a first reference voltage and a second reference voltage, wherein the second reference voltage is less than the first reference voltage. Specifically, when the over-discharge protection module determines that the first sampling voltage is greater than or equal to the first reference voltage, the main control unit controls the main switch unit to turn on; when the over-discharge protection module determines that the first sampling voltage is less than the first reference voltage but greater than or equal to the second reference voltage, the main control unit controls the main switch unit to turn on intermittently; and when the over-discharge protection module determines that the first sampling voltage is less than the second reference voltage, the main control unit controls the main switch unit to turn off.

7. The battery protection circuit according to claim 1, characterized in that, The battery protection circuit further includes a battery voltage sampling unit, which is connected to the positive and negative terminals of the battery. The battery voltage sampling unit is used to sample the battery voltage to obtain a first sampling voltage and a second sampling voltage. The first sampling voltage and the second sampling voltage are used to characterize the same battery voltage. The first sampling voltage is less than the second sampling voltage. The over-discharge protection module is connected to the first sampling voltage and the second sampling voltage. The over-discharge protection module is also connected to a first reference voltage. Specifically, when the over-discharge protection module determines that the first sampling voltage is greater than or equal to the first reference voltage, the main control unit controls the main switch unit to turn on. When the over-discharge protection module determines that the first sampling voltage is less than the first reference voltage and the second sampling voltage is greater than or equal to the first reference voltage, the main control unit controls the main switch unit to turn on intermittently. When the second sampling voltage is less than the first reference voltage, the main control unit controls the main switch unit to turn off.

8. The battery protection circuit according to any one of claims 1-7, characterized in that, The battery protection circuit also includes a boost unit, which is connected in series with the system circuit. The first end of the boost unit is connected to the positive terminal of the battery, and the second end of the boost unit is connected to the system circuit. The boost unit is used to boost the voltage of the battery when it is low. The boost unit is connected to the main control unit to control whether the boost unit performs the boost.

9. The battery protection circuit according to claim 8, characterized in that, The control terminal of the boost unit is connected to the main control unit. The battery protection circuit also includes a voltage judgment unit. The first input terminal of the voltage judgment unit is connected to the battery voltage, and its output terminal is connected to the main control unit. Specifically, when the battery voltage is greater than or equal to a preset fifth threshold voltage, the main control unit controls the boost unit to enable it to save energy; when the battery voltage is less than the fifth threshold voltage, the main control unit controls the boost unit to enable it to boost the battery voltage. The fifth threshold voltage is between the first threshold voltage and the second threshold voltage.

10. The battery protection circuit according to any one of claims 1-7, characterized in that, The battery protection circuit is located on the same chip; or... The battery protection circuit, excluding the main switch unit, is located on the first chip, while the main switch unit is located on the second chip.

11. A battery assembly, characterized in that, include: Battery; The battery protection circuit as described in any one of claims 1-10, wherein the battery protection circuit is connected to the battery.

12. An electronic device, characterized in that, include: The system circuit includes a main load and an auxiliary load connected in parallel; The battery protection circuit as described in any one of claims 1-10 or the battery assembly as described in claim 11.

13. The electronic device according to claim 12, characterized in that, The auxiliary load includes a remote positioning module.

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