Energy-saving battery protection circuit, battery assembly and electronic device

Abstract

The application provides an energy-saving battery protection circuit, comprising: a power supply positive terminal, a power supply negative terminal, a main control unit, a main switch unit; a current detection unit, which is used to obtain current sampling information, the current sampling information being used to represent information of a current flowing through the main switch unit, and the current detection unit being further used to process the current sampling information to obtain second current information; a first communication terminal, which is connected with the current detection unit to obtain the second current information, and is further connected with a system circuit to deliver the second current information to the system circuit; and a third communication terminal, which is used to be connected with the system circuit, and is used to control whether at least part of the current detection unit works according to a signal of the system circuit. The application 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 an energy-saving battery protection circuit, battery assembly, and electronic device. Background Technology

[0002] Battery modules are widely used in electronic devices such as mobile phones, tablets, and Bluetooth headsets. 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 supply cables. Generally, a battery module includes a battery and a battery protection circuit electrically connected to it. This circuit protects against abnormal conditions during battery charging or discharging.

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

[0004] Related technologies also propose transmitting various information detected by the battery protection circuit to the system circuit, such as the battery current, for processing. For example, the system circuit's processor can process this information to obtain information such as the battery's current state. However, the battery protection circuit consumes power from information acquisition and processing to transmission to the system circuit, increasing its power consumption. Moreover, the battery's capacity is relatively low, thus reducing the standby time of electronic devices and hindering their usability. Utility Model Content

[0005] The technical problem to be solved by the embodiments of this application is to provide an energy-saving battery protection circuit, battery component, and electronic device, addressing the shortcomings of the prior art. This reduces the power consumption of the battery protection circuit.

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

[0007] The system includes a power supply terminal, a power ground terminal, a main control unit, and a main switch unit. The power supply terminal and the power ground terminal are used to connect to the battery. 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 to control whether the line between the battery and the system circuit is conductive.

[0008] A current detection unit is used to obtain current sampling information, which is used to characterize the current flowing through the main switching unit. The current detection unit is also used to process the current sampling information to obtain second current information.

[0009] A first communication terminal is connected to the current detection unit to obtain second current information. The first communication terminal is also connected to the system circuit to transmit the second current information to the system circuit.

[0010] The third communication terminal is used to connect to the system circuit, and the third communication terminal is used to control whether at least some units of the current detection unit work according to the signal of the system circuit.

[0011] Optionally, when the third communication terminal receives the second signal sent by the system circuit, the current detection unit is in a working state, and then the first communication terminal outputs the second current information to the system circuit; when the third communication terminal receives the first signal sent by the system circuit, at least some units of the current detection unit are controlled to switch to a non-working state, wherein the second signal is used to indicate that the system circuit needs to obtain the second current information, and the first signal is used to indicate that the system circuit does not need to obtain the second current information.

[0012] Optionally, the time it takes for the third communication terminal to receive the second signal per unit time is less than the time it takes to receive the first signal; or,

[0013] The ratio of the time it takes for the third communication terminal to receive the second signal to the time it takes to receive the first signal per unit time is less than or equal to 1:5.

[0014] Optionally, the battery protection circuit further includes a battery protection unit connected to the main control unit. When the battery protection unit determines that the battery charging or discharging is abnormal, it outputs a protection signal to the main control unit, and the main control unit controls the main switch unit to disconnect and cut off.

[0015] The battery protection circuit further includes an enable control unit, which is connected to the third communication terminal and the battery protection unit. When the enable control unit receives a first signal or a protection signal, the enable control unit controls at least some units of the current detection unit to be in a non-operating state.

[0016] Optionally, the protection signal includes a charging protection signal and a discharging protection signal;

[0017] When the enabling control unit receives a charging protection signal, it controls at least a portion of the current detection unit to be in an inactive state during battery charging; or...

[0018] When the enable control unit receives a discharge protection signal, it controls at least some units of the current detection unit to be in a non-operating state during battery discharge.

[0019] Optionally, the protection signal includes a charging protection signal and a discharging protection signal; the main switching unit includes a current sampling tube, which is used to control whether charging or discharging is performed; and the current detection unit includes a first mirror tube, which is mirrored with the current sampling tube.

[0020] The battery protection circuit also includes an enable control unit, which is connected to the battery protection unit and the third communication terminal. When the enable control unit receives a charging protection signal or a discharging protection signal, the enable control unit is also used to control whether at least some units of the current detection unit work according to the current sampling tube.

[0021] Optionally, the current detection unit includes a current sampling unit and a processing unit. The current sampling unit is connected in series with the system circuit and is used to output current sampling information. The processing unit is connected to the current sampling unit, the first communication terminal, and the third communication terminal. The processing unit is used to convert the current sampling information into second current information.

[0022] The enable terminal of the processing unit is connected to the third communication terminal to control whether the processing unit works through the system circuit.

[0023] Optionally, the current detection unit includes a current sampling unit and a processing unit; the main switching unit includes a current sampling tube, which is connected in series with the system circuit; the current sampling unit includes a first mirror tube, which forms a current mirror with the current sampling tube to obtain current sampling information.

[0024] The first image transistor is connected to the first end of the current sampling transistor, the control end of the first image transistor is connected to the control end of the current sampling transistor, and the second end of the first image transistor is used to output current sampling information.

[0025] The current sampling unit further includes a second operational amplifier and a matching transistor. The two input terminals of the second operational amplifier are respectively connected to the second terminal of the first image transistor and the second terminal of the current sampling transistor. The second terminal of the first image transistor is also connected to the first terminal of the matching transistor. The second terminal of the matching transistor is connected to the processing unit. The control terminal of the matching transistor is connected to the output terminal of the second operational amplifier. The processing unit is used to convert the current sampling information into second current information.

[0026] The enable terminal of the second operational amplifier is connected to the third communication terminal so that the current detection unit is in a non-operating state when the second operational amplifier is not working.

[0027] Optionally, the processing unit includes a fourth switch, a second mirror transistor, and a switching resistor, wherein the fourth switch is connected in series with the matching transistor, the second mirror transistor and the fourth switch form a current mirror, the switching resistor is connected in series with the second mirror transistor, and the second current information is the voltage across the switching resistor;

[0028] It also includes a fifth switch, the control terminal of which is connected to the third communication terminal. The fifth switch is connected to the control terminal of the second mirror tube or connected in series with the second mirror tube. When the third communication terminal is used to control the current detection unit to be in a non-working state according to the signal of the system circuit, the fifth switch is used to control the second mirror tube to disconnect or to control the branch where the second mirror tube is located to disconnect.

[0029] Optionally, the switching resistor is a peripheral device of the chip where the remaining part of the processing unit is located.

[0030] Optionally, the current detection unit includes a current sampling unit, the current sampling unit includes a sampling resistor, the sampling resistor is connected in series with the main switching unit, and the current sampling information is the voltage across the sampling resistor; or,

[0031] The current detection unit includes a current sampling unit, which in turn includes a main switching unit. The current sampling information is the voltage across the main switching unit; or...

[0032] The battery protection circuit is located on the same chip.

[0033] A second aspect of this application provides a battery assembly, characterized in that it includes:

[0034] Battery;

[0035] The battery protection circuit described above is connected to the battery.

[0036] A third aspect of this application provides an electronic device, comprising:

[0037] The system circuit includes a second communication terminal and a fourth communication terminal;

[0038] The aforementioned battery protection circuit or the aforementioned battery assembly;

[0039] The system circuit is connected to the battery via the main switch unit of the battery protection circuit;

[0040] The second communication terminal is connected to the first communication terminal, and the fourth communication terminal is connected to the third communication terminal. The fourth communication terminal is used to output a first signal or a second signal to control whether at least some units of the current detection unit are working.

[0041] The battery protection circuit of this embodiment includes a current detection unit, a first communication terminal, and a third communication terminal. The current detection unit obtains current sampling information, which characterizes the current flowing through the main switching unit. The current detection unit also processes the current sampling information to obtain second current information. The first communication terminal transmits the second current information to the system circuit. The third communication terminal controls whether at least some units of the current detection unit operate according to signals from the system circuit. Since the system circuit can control at least some units of the current detection unit to be in an inactive state when the second current information is not needed, this configuration reduces the power consumption of the battery protection circuit, increases the battery's operating time, and enhances the competitiveness of the battery protection circuit. Attached Figure Description

[0042] 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.

[0043] Figure 1a This is a circuit block diagram of the electronic device according to the first embodiment of this application;

[0044] Figure 1b This is a circuit block diagram of an electronic device according to another embodiment of this application;

[0045] Figure 2 This is a circuit block diagram of the battery protection circuit according to the first embodiment of this application;

[0046] Figure 3 This is a circuit block diagram of the battery protection circuit according to the second embodiment of this application;

[0047] Figure 4 This is a circuit block diagram of a battery protection circuit according to another embodiment of this application;

[0048] Figure 5 This is a circuit block diagram of a battery protection circuit according to another embodiment of this application. Detailed Implementation

[0049] 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.

[0050] 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.

[0051] First Embodiment

[0052] This application provides an electronic device, such as a mobile phone, tablet computer, Bluetooth headset, or other consumer electronics. Please refer to [link to relevant documentation]. Figure 1a The electronic device includes a battery 110, a battery protection circuit 200, and a system circuit 300. The system circuit 300 is, for example, a load or a charger. In this embodiment, the system circuit 300 is used as a load for explanation. The system circuit 300 includes a processor, etc. The system circuit 300 is electrically connected to the battery 110 via the battery protection circuit 200. The battery 110 is used to supply power to the system circuit 300 or to be charged by the system circuit 300.

[0053] In this embodiment, the battery protection circuit 200 is electrically connected to the positive and negative terminals of the battery 110, and the system circuit 300 is electrically connected to the battery protection circuit 200. The battery 110 supplies power to the battery protection circuit 200, and the battery protection circuit 200 protects the battery 110, for example, when the battery 110 is overcharged, over-discharged, overcurrent during charging, or overcurrent during discharging. Since how the battery protection circuit 200 protects the battery 110 from overcharge, over-discharge, overcurrent during charging, and overcurrent during discharging is a common technical means in the art, it will not be described in detail here. In this embodiment, the number of batteries 110 is one or more, preferably one. When there are multiple batteries 110, they can be connected in parallel, in series, or in a combination of series and parallel connections. The batteries 110 are preferably lithium batteries, and their capacities are, for example, 1000mAh-15000mAh, such as 1000mAh, 2000mAh, 3000mAh, 4000mAh, 5000mAh, 6000mAh, 7000mAh, 8000mAh, 9000mAh, 10000mAh, 11000mAh, 12000mAh, 13000mAh, 14000mAh, and 15000mAh. In this embodiment, a first resistor R1 and a first capacitor C1 are also provided between the battery 110 and the battery protection circuit 200. The first resistor R1 and the first capacitor C1 are used for filtering. In other embodiments of this application, other circuits or electronic components may be provided between the battery 110 and the battery protection circuit 200. Additionally, in other embodiments of this application, the first resistor R1 and the first capacitor C1 may not be provided.

[0054] 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 220, a main control unit 230, and a main switch unit 240.

[0055] 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 110, so that the battery 110 can supply power to the battery protection circuit 200. At the same time, the battery 110 forms a loop through the battery protection circuit 200 and the system circuit 300.

[0056] In this embodiment, the battery protection unit 220 is used to control the battery 110 to stop charging and discharging when an abnormality in charging or discharging is detected during the charging and discharging process of the battery 110, thereby protecting the battery 110. In this embodiment, the battery protection circuit 200 protects the battery 110 from overcharging, over-discharging, and overcurrent during charging / discharging, preventing permanent damage to the battery 110. In this embodiment, the battery protection unit 220 includes a voltage protection unit (not shown in the figure) and a current protection unit 221. In other embodiments of this application, the battery protection unit 220 includes a current protection unit 221. In this embodiment, the battery protection unit 220 is connected to the main control unit 230. When the battery protection unit 220 detects an abnormality in charging or discharging of the battery 110, the battery protection unit 220 outputs a corresponding protection signal to the main control unit 230, and the main control unit 230 controls the main switch unit 240 to disconnect and cut off.

[0057] The voltage protection unit includes an overcharge protection unit and an over-discharge protection unit. The overcharge protection unit is used to protect the battery 110 when it detects that the battery 110 voltage is too high during the charging process, such as stopping the charging of the battery 110, to prevent damage to the battery 110 or safety problems.

[0058] The over-discharge protection unit is used to protect the battery 110 when it detects that the battery 110 voltage is too low during the discharge process. For example, it controls the battery 110 to only discharge to a minimum level. Generally, it stops supplying power to the system circuit 300 to prevent the battery 110 from being over-discharged and causing permanent damage to the battery 110.

[0059] The current protection unit 221 is used to protect the battery 110 when excessive discharge current or excessive charging current is detected during the discharge or charging process of the battery 110. For example, the battery 110 may stop discharging or stop charging, so as to prevent the excessive discharge current or charging current from causing permanent damage to the battery 110 or causing safety problems.

[0060] In this embodiment, one end of the main switch unit 240 is connected to the negative terminal of the battery 110. Figure 1a ) or positive electrode ( Figure 1bThe main switch unit 240 is connected to the system circuit 300 via the system terminal VM. The control terminal of the main switch unit 240 is connected to the main control unit 230, which controls the main switch unit 240 to turn on or off, thereby controlling the battery 110 to supply power to or stop supplying power to the system circuit 300. In this embodiment, the main switch unit 240 includes a charging switch 241 and a discharging switch 242, which are connected in series. Both the charging switch 241 and the discharging switch 242 are MOSFETs. The control terminals of the charging switch 241 and the discharging switch 242 are electrically connected to the main control unit 230, allowing the main control unit 230 to control the charging switch 241 and the discharging switch 242 to turn on and off respectively. However, this application is not limited to this. In other embodiments of this application, the main switch unit 240 includes a main switch transistor 243, and the battery protection circuit 200 includes a substrate switching control unit 244 (see [link to application]). Figure 5 The main switch 243 is a MOSFET, and its control terminal is electrically connected to the main control unit 230. The substrate switching control unit 244 is also electrically connected to the main control unit 230. The substrate switching control unit 244 is used to correctly bias the substrate of the main switch 243. In other embodiments of this application, the main switch unit 240 can also be implemented in other ways, such as including only one switch. In this embodiment, the main switch unit 240 is used to control the battery 110 to supply power to the system circuit 300. Specifically, a loop is formed between the battery 110, the main switch unit 240 of the battery protection circuit 200, and the system circuit 300 to supply power to the system circuit 300. In other embodiments of this application, the main switch unit 240 is used to control whether the system circuit 300 charges the battery 110.

[0061] In this embodiment, the battery protection circuit 200 further includes a current detection unit 210. The current detection unit 210 is used to sample and obtain current sampling information, which represents the current flowing through the main switch unit 240, that is, the output current of the battery 110 or the charging current of the battery 110. The current detection unit 210 is also used to process the current sampling information and output it to the system circuit 300. In this embodiment, the current detection unit 210 is also connected to the current protection unit 221. The current sampling information is output to the current protection unit 221. The current protection unit 221 receives the current sampling information and compares it with a preset current protection threshold to determine whether to output an overcurrent protection signal. If the comparison result is abnormal (the current sampling information is greater than the current protection threshold and lasts for a preset time), the current protection unit 221 outputs an overcurrent protection signal. If the comparison result is not abnormal, the current protection unit 221 outputs a normal signal. When the main control unit 230 receives an overcurrent protection signal, the main control unit 230 controls the main switch unit 240 to disconnect and cut off, so as to stop charging or stop discharging, and correspondingly controls the charging switch 241 to disconnect and cut off or controls the discharging switch 242 to disconnect and cut off.

[0062] Please refer to the above. Figure 1a and Figure 2 In this embodiment, the current detection unit 210 includes a current sampling unit 211, which includes a sampling resistor Rs. The sampling resistor Rs is connected in series with the main switch unit 240. The voltage across the sampling resistor Rs represents the current sampling information and can represent the current flowing through the main switch unit 240. In one implementation, the first end of the sampling resistor Rs is connected to the main switch unit 240, and the second end of the sampling resistor Rs is connected to the negative terminal of the battery 110. Figure 1a ) or the positive terminal of battery 110 ( Figure 1b The sampling resistor Rs is connected in series with the main switch unit 240, so the voltage at the first end of the sampling resistor Rs is the current sampling information. At this time, the first end of the sampling resistor Rs is also connected to the current protection unit 221 to output the current sampling information to the current protection unit. In another implementation, the sampling resistor Rs can be located in other positions, as long as it is connected in series with the main switch unit 240. In this case, the voltage across the sampling resistor Rs is the current sampling information, and the current sampling information is equal to the voltage difference across the sampling resistor Rs. In this embodiment, the sampling resistor Rs can be a precision resistor or a parasitic resistor; this embodiment does not impose any restrictions. Furthermore, in this embodiment, since the sampling resistor Rs is located in the main circuit, the power consumption consumed by the sampling resistor Rs is not part of the power consumption of the battery protection circuit.

[0063] Since the current sampling information may be small or large, it may exceed the range of the signal received by the system circuit, such as the range of the processor of the system circuit. In order to avoid this situation, the current detection unit 210 also includes a processing unit 212. The processing unit 212 is used to receive the current sampling information. In the figure, the processing unit 212 is connected to both ends of the sampling resistor. After processing the current sampling information, the processing unit 212 obtains the second current information. The second current information is used to output to the system circuit, such as the processor of the system circuit.

[0064] In this embodiment, the processing unit 212 is, for example, an amplification unit or a reduction unit. This embodiment uses the processing unit 212 as an amplification unit as an example. The amplification unit can also reduce errors caused by interference with the current sampling information during transmission, such as signal errors caused by interference between terminals of the battery protection circuit 200 and the system circuit 300, thus improving anti-interference capability. In this embodiment, the amplification unit amplifies the current sampling information to obtain second current information, which is then transmitted to the system circuit 300. In this embodiment, the ratio of the current sampling information to the second current information is less than or equal to 1:50, for example, 1:50, 1:100, 1:500, 1:1000, 1:10000, etc. Since the second current information is much larger than the current sampling information, even minor environmental or transmission interference has limited impact on the second current information, thereby improving the anti-interference capability of signal transmission. Similarly, the amplified current sampling information is within the detection range of the system circuit. Furthermore, in other embodiments of this application, when the processing unit 212 is a reduction unit, the primary consideration is that the second current information must be within the range of the system circuit.

[0065] Please continue to refer to the above. Figure 1a and Figure 2 In this embodiment, the amplification unit includes a first operational amplifier 0A1. The first input terminal of the first operational amplifier 0A1 is connected to the first terminal of the sampling resistor Rs, and the second input terminal of the first operational amplifier 0A1 is connected to the second terminal of the sampling resistor Rs. The output terminal of the first operational amplifier 0A1 is used to output second current information, which is then output to the system circuit 300. In this embodiment, the first operational amplifier 0A1 amplifies the current sampling information to obtain the second current information. The amplification factor of the first operational amplifier 0A1 is, for example, 100 times, 500 times, 1000 times, 2000 times, 5000 times, 10000 times, etc., and the ratio of the second current information to the current sampling information is, for example, greater than or equal to 50.

[0066] In order to transmit the second current information to the system circuit 300, in this embodiment, the battery protection circuit 200 is also connected to the system circuit 300, for example, to the processor of the system circuit 300. The battery protection circuit 200 outputs the second current information to the processor. Based on the second current information and the obtained voltage of the battery 110, the processor evaluates the state of the battery 110, for example, evaluates the remaining charge (SOC) of the battery 110, and then controls the charging and discharging processes of the battery 110. In this embodiment, the battery protection circuit 200 includes a first communication terminal CS0, and the system circuit 300 includes a second communication terminal CS1. The first communication terminal CS0 and the second communication terminal CS1 are electrically connected, and the second current information is transmitted through the first communication terminal.

[0067] CS0 and the second communication terminal CS1 transmit data to the system circuit 300.

[0068] Generally, the battery protection circuit 200 itself has very high power consumption requirements (overall power consumption is several μA). In this embodiment, due to the addition of the processing unit 212, the use of the processing unit 212 increases the power consumption of the battery protection circuit 200, leading to increased power consumption of the battery 110, reduced battery 110 usage time, and reduced competitiveness of the battery protection circuit 200. To improve this problem, reduce the power consumption of the battery protection circuit 200, and improve its competitiveness, in this embodiment, at least some units of the current detection unit 210 are not constantly operating. In this embodiment, the current sampling unit 211 is constantly operating. The current sampling unit 211 is located in the main circuit, and the power consumption of the current sampling unit 211 is not part of the power consumption of the battery protection circuit 200. However, the processing unit 212 is not constantly operating, that is, the processing unit 212 is not operating for part of the time, thereby reducing the power consumption of the battery protection circuit 200.

[0069] To prevent at least some units of the current detection unit 210 from being continuously operational, specifically to prevent the processing unit 212 from being continuously operational, in this embodiment, the battery protection circuit 200 further includes a third communication terminal CSEN0. Correspondingly, the system circuit 300 includes a fourth communication terminal CSEN1, which is connected to the third communication terminal CSEN0. In this embodiment, the signal from the third communication terminal CSEN0 is used to control whether the processing unit 212 is operational, specifically through the enable terminal of the processing unit 212. When the system circuit 300 communicates with the fourth communication terminal CSEN1 and the third communication terminal CSEN0, the signal from the third communication terminal CSEN0 is used to control whether the processing unit 212 is operational.

[0070] When the CSEN0 control processing unit 212 is not working, for example, when the system circuit 300 outputs the first signal, the processing unit 212 is deactivated and in a non-working state, and the voltage of the first communication terminal CS0 is 0. When the system circuit 300 controls the processing unit 212 to work through the fourth communication terminal CSEN1 and the third communication terminal CSEN0, for example, when the system circuit 300 outputs the second signal, the processing unit 212 is enabled and in a working state, and the first communication terminal CS0 outputs the second current information. Thus, by controlling whether the processing unit 212 is enabled or not through the system circuit 300, the power consumption of the processing unit 212 can be controlled. In this embodiment, when the system circuit 300 is working normally and needs to obtain the current flowing through the main switch unit 240, the system circuit 300 outputs a second signal, which controls the processing unit 212 to switch to a working state through the fourth communication terminal CSEN1 and the third communication terminal CSEN0. After the processing unit 212 starts working, the first communication terminal CS0 outputs the second current information, and the system circuit 300 receives the second current information through the second communication terminal CS1. Thus, the system circuit 300 obtains the current flowing through the main switch unit 240. The system circuit 300 does not need to detect the current flowing through the main switch unit 240 itself, which helps to reduce costs. When the system circuit 300 receives the current flowing through the main switch unit 240, the system circuit 300 outputs a first signal, which controls the processing unit 212 to be in a non-working state through the fourth communication terminal CSEN1 and the third communication terminal CSEN0. At this time, the processing unit 212 is de-enabled, thereby reducing the power consumption of the battery protection circuit 200. In this embodiment, the processing unit 212 is deactivated most of the time. The system circuit 300 only controls the processing unit 212 to be enabled when the system circuit 300 needs to obtain the current flowing through the main switch unit 240, after which the processing unit 212 is activated.

[0071] To minimize the power consumption of the battery protection circuit 200, in this embodiment, the time for the third communication terminal CSEN0 to receive the second signal per unit time is less than the time it receives the first signal. Therefore, the processing unit 212 is in an operating state for less time than it is in an inactive state. Generally, the ratio of the time for the third communication terminal CSEN0 to receive the second signal to the time it receives the first signal per unit time is less than or equal to 1:5, for example, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, 1:20, 1:30, 1:50, 1:100, etc. Preferably, the ratio is less than or equal to 1:10. This setting can greatly reduce the power consumption of the battery protection circuit 200 while also meeting the requirements of the system circuit 300, thus enhancing the competitiveness of the battery protection circuit 200.

[0072] In other embodiments of this application, the sampling resistor Rs may not be provided. In this case, the current sampling unit 211 includes a main switch unit 240. The power consumption of the main switch unit 240 is not part of the power consumption of the battery protection circuit 200. That is, the main switch unit 240 is shared and has two functions: one is to turn the main circuit on or off, and the other is to obtain current sampling information. The voltage on the main switch unit 240 is the current sampling information, for example, the voltage of the system terminal VM is the current sampling information. Compared with obtaining current sampling information through the sampling resistor Rs, this method is lower in cost and simpler. However, the accuracy of the current sampling information obtained by this method is reduced because the on-resistance of the main switch unit 240 will change with various conditions, such as temperature and battery voltage.

[0073] In this embodiment, the components of the battery protection circuit 200, except for the main switch unit 240 and the sampling resistor Rs, are located on the same integrated circuit chip. That is, the main switch unit 240 and the sampling resistor Rs are external. The main switch unit 240 is located on another integrated circuit chip, and the sampling resistor Rs is an external component.

[0074] Generally speaking, the sampling resistor Rs is a high-precision resistor, which is costly, resulting in a higher cost for the battery protection circuit 200. Furthermore, the external sampling resistor Rs increases the number of external components. Also, when the battery protection circuit 200 is fully integrated, the sampling resistor Rs solution cannot be used. To reduce cost, maintain accuracy, reduce the number of external components, and allow for the use of a fully integrated battery protection circuit 200, this application provides a second embodiment.

[0075] Second Embodiment

[0076] Please see Figure 3 , Figure 3 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 sampling resistor Rs is not included.

[0077] Please refer to the above. Figure 1a and Figure 3In this embodiment, the main switching unit 240 includes a charging switch 241 and a discharging switch 242, which are connected in series. The charging switch 241 and the discharging switch 242 are transistors, such as MOSFETs or bipolar transistors. In this embodiment, the power consumption of the current sampling unit 211 belongs to the power consumption of the battery protection circuit 200. The current sampling unit 211 includes a first mirror transistor MK1, which forms a current mirror with either the charging switch 241 or the discharging switch 242. Thus, the current flowing through the first mirror transistor MK1 can characterize the current flowing through the main switching unit 240. In this embodiment, the first mirror transistor MK1 forms a current mirror with the discharging switch 242. Here, the switch in the main switching unit 240 that forms a current mirror with the first mirror transistor MK1 is called a current sampling transistor, that is, the discharging switch 242 is a current sampling transistor. The first mirror transistor MK1 and the discharging switch 242 are of the same type and have the same device structure, for example, both are NMOS transistors or both are PMOS transistors, and they are manufactured using the same process. In the illustration, it is illustrated that both are NMOS transistors. In this embodiment, the first terminal of the discharge switch 242 is connected to the power ground terminal GND, the second terminal of the discharge switch 242 is connected to the charging switch 241, and the control terminal of the discharge switch 242 is connected to the main control unit 230. The first terminal of the first image transistor MK1 is connected to the first terminal of the discharge switch 242, the second terminal of the first image transistor MK1 is used to output current sampling information, and the control terminal of the first image transistor MK1 is connected to the control terminal of the discharge switch 242. Therefore, the potentials of the first terminal of the first image transistor MK1 and the first terminal of the discharge switch 242 are equal, and the potentials of the control terminals of the first image transistor MK1 and the discharge switch 242 are also equal. Thus, the current flowing through the first image transistor MK1 and the current flowing through the discharge switch 242 are approximately equal to the ratio of the number of MOSFETs between them. In other embodiments of this application, the first image transistor MK1 and the charging switch 241 form a current mirror, that is, the charging switch 241 is a current sampling transistor.

[0078] To ensure that the first image transistor MK1 and the second terminal of the discharge switch 242 operate at the same operating point, and to achieve precise matching between the first image transistor MK1 and the discharge switch 242, the current flowing through the first image transistor MK1 and the current flowing through the discharge switch 242 are equal to the width-to-length ratio of their channels. For example, the ratio of the current flowing through the discharge switch 242 to the current flowing through the first image transistor MK1 is greater than or equal to 100:1, such as 100:1, 500:1, 1000:1, 5000:1, 10000:1, etc. In this embodiment, the current sampling unit 211 further includes a second operational amplifier 0A2 and a matching transistor PK1. The first input terminal of the second operational amplifier 0A2 is connected to the second terminal of the discharge switch 242, and the second input terminal of the second operational amplifier 0A2 is connected to the second terminal of the first image transistor MK1. The second input terminal of the first image transistor MK1 is also connected to the first terminal of the matching transistor PK1. The second terminal of the matching transistor PK1 is used to output current sampling information; that is, the matching transistor PK1 and the first image transistor MK1 are connected in series. The control terminal of the matching transistor PK1 is connected to the output terminal of the second operational amplifier 0A2. With this configuration, the second operational amplifier 0A2 can adjust the output current of the matching transistor PK1, ensuring that the potential of the second terminal of the first image transistor MK1 is equal to the potential of the second terminal of the discharge switch 242. This ensures that the current flowing through the first image transistor MK1 and the current flowing through the discharge switch 242 are precisely equal to the width-to-length ratio of their channels. Furthermore, since the first image transistor MK1 and the matching transistor PK1 are connected in series, the current flowing through the first image transistor MK1 is equal to the current flowing through the matching transistor PK1. In this embodiment, the current sampling signal is the current.

[0079] In this embodiment, the processing unit 212 includes a fourth switch K4, a second mirror transistor MK2, and a switching resistor Rz. The fourth switch K4 and the second mirror transistor MK2 form a current mirror. The second mirror transistor MK2 and the fourth switch K4 are of the same type and have the same device structure. The current ratio between the two is equal to the width-to-length ratio of their channels. For example, the ratio of the current flowing through the second mirror transistor MK2 to the current flowing through the fourth switch K4 is not limited, such as 1:1, 2:1, 5:1, 1:2, 1:5, etc., preferably 1:1. In this embodiment, the fourth switch K4 is connected in series with the matching transistor PK1. Specifically, the first terminal of the fourth switch K4 is connected to the second terminal of the matching transistor PK1, the second terminal of the fourth switch K4 is connected to the power supply terminal VDD, and the control terminal of the fourth switch K4 is connected to its first terminal. Simultaneously, the second terminal of the second image transistor MK2 is connected to the second terminal of the fourth switch K4, the control terminal of the second image transistor MK2 is connected to the control terminal of the fourth switch K4, the first terminal of the second image transistor MK2 is connected to the first communication terminal CS0, the first communication terminal CS0 is connected to the first terminal of the conversion resistor Rz, and the second terminal of the conversion resistor Rz is connected to the power supply ground terminal GND. In this embodiment, the current sampling information is converted into second current information through the fourth switch K4, the second image transistor MK2, and the conversion resistor Rz. The current sampling information is current, and the second current information is voltage, specifically the voltage relative to the power supply ground terminal. This second current information is used to output to the system circuit 300. In this embodiment, the fourth switch K4 and the second image transistor MK2 are, for example, MOSFETs or transistors. In the illustration, both the fourth switch K4 and the second image transistor MK2 are PMOS transistors.

[0080] In this embodiment, the current flowing through the main switching unit 240 is detected using a current mirror method to obtain current sampling information. This current sampling information is proportional to the current flowing through the current sampling tube, which is also proportional to the current in the system circuit 300. Furthermore, the current sampling information is independent of the on-resistance of the current sampling tube. Therefore, when the on-resistance changes due to external environmental changes or variations in electrical parameters, the current sampling information remains unchanged. This allows the current sampling information to accurately reflect the magnitude of the current in the system circuit 300. Because the current sampling information is highly accurate, it is then converted into second current information, which is also very accurate. This facilitates accurate assessment of the battery 110's state by the system circuit 300, and the current detection method is low-cost.

[0081] Additionally, in other embodiments of this application, please refer to [reference needed]. Figure 1b and Figure 4When the first terminal of the discharge switch 242 is connected to the power supply terminal VDD, the first terminal of the first image transistor MK1 is connected to the first terminal of the discharge switch 242, the second terminal of the first image transistor MK1 is connected to one end of the matching transistor PK, the other end of the matching transistor PK is connected to one end of the conversion resistor Rz, and the other end of the conversion resistor Rz is connected to the power supply ground terminal, thereby converting the voltage relative to the power supply ground terminal GND, that is, obtaining the second current information, which is then output to the system circuit. Here, the processing unit 212 includes the conversion resistor Rz.

[0082] Furthermore, the main switch unit 240 is not limited to including the discharge switch 242 and the charging switch 241. For other embodiments of this application, please refer to [reference needed]. Figure 1a and Figure 5 The main switching unit 240 includes a main switching transistor 243, and the battery protection circuit 200 includes a substrate switching control unit 244. The first terminal of the main switching transistor 243 is connected to the power ground terminal GND (this is used as an example in the figure) or the power supply terminal VDD. The second terminal of the main switching transistor 243 is connected to the system circuit 300 via the system terminal VM. The control terminal of the main switching transistor 243 is connected to the main control unit 230. The substrate of the main switching transistor 243 is connected to the substrate switching control unit 244. The substrate switching control unit 244 is used to control the substrate of the main switching transistor 243 to switch to its first terminal or second terminal. In this embodiment, the first image transistor MK1 and the main switch transistor 243 are of the same type. The first end of the first image transistor MK1 is connected to the first end of the main switch transistor 243, the control end of the first image transistor MK1 is connected to the control end of the main switch transistor 243, the second end of the first image transistor MK1 is connected to the first end of the matching transistor PK1, and the substrate of the first image transistor MK1 is connected to the substrate of the main switch transistor 243. That is, the substrate of the first image transistor MK1 is also switchable, changing with the substrate of the main switch transistor 243. Furthermore, when the substrate of the main switch transistor 243 is controlled to be connected to its first end, the substrate of the first image transistor MK1 is also connected to the first end of the main switch transistor 243; when the substrate of the main switch transistor 243 is controlled to be connected to its second end, the substrate of the first image transistor MK1 is also connected to the second end of the main switch transistor 243. In other words, here, the first image transistor MK1 and the main switch transistor 243 form a current mirror, and the current sampling transistor is the main switch transistor 243. In this embodiment, the main switch 243 is a MOS transistor, for example, an NMOS transistor in the figure.

[0083] In this embodiment, both the current sampling unit 211 and the processing unit 212 require electrical energy. To reduce power consumption, please refer to [reference needed]. Figure 1a , Figures 3-5In this embodiment, the current detection unit 210 is not always operational. Specifically, the battery protection circuit 200 also includes a third communication terminal CSEN0, and correspondingly, the system circuit 300 includes a fourth communication terminal CSEN1, which is connected to the third communication terminal CSEN0. In this embodiment, the signal from the third communication terminal CSEN0 is used to control whether the current detection unit 210 is operational, specifically controlling whether the second operational amplifier 0A2 is operational. When the second operational amplifier 0A2 is not operational, its power consumption is 0. When the second operational amplifier 0A2 is operating normally, it consumes power normally. Moreover, when the second operational amplifier 0A2 is not operational, the matching transistor PK1 will be disconnected, resulting in a theoretical current flowing through the fourth switch K4 of 0. Consequently, the entire current sampling unit 211 and the entire processing unit 212 will not operate, meaning the entire current detection unit 210 is not operational. In addition, when the second operational amplifier 0A2 is not working, the fourth switch K4 may actually have a certain leakage current. Due to the mirror, there will be current in the branch where the second mirror transistor MK2 is located. This leakage current will be transmitted to the system circuit 300 through the first communication terminal CS0, causing the system circuit 300 to receive an incorrect signal.

[0084] To reduce leakage current and further reduce power consumption, and to prevent the system circuitry from receiving incorrect signals, please refer to [link to relevant documentation]. Figure 3 The processing unit 212 also includes a fifth switch K5. The first terminal of the fifth switch K5 is connected to the power supply terminal VDD, and the second terminal of the fifth switch K5 is connected to the control terminal of the second image transistor MK2. The control terminal of the fifth switch K5 is controlled by the third communication terminal CSEN0 signal. When the third communication terminal CSEN0 controls the current detection unit 210 to not work, the fifth switch K5 is turned on, thus the second image transistor MK2 is turned off. When the third communication terminal CSEN0 controls the current detection unit 210 to work, the fifth switch K5 is turned off, and the voltage at the control terminal of the second image transistor MK2 is the same as the voltage at the first terminal of the fourth switch. In this embodiment, the fifth switch K5 can be a MOS transistor or a transistor; in the figure, it is a PMOS transistor. Additionally, in other embodiments of this application, the fifth switch K5 can also be connected in series in the branch where the second image transistor MK2 is located, for example in… Figure 3 , Figure 5 The fifth switch K5 is connected in series between the second mirror transistor MK2 and the first communication terminal CS0. In this case, when the third communication terminal CSEN0 controls the current detection unit 210 to not work, the fifth switch K5 is disconnected and cut off, and the branch where the second mirror transistor MK2 is located is disconnected and cut off. When the third communication terminal CSEN0 controls the current detection unit 210 to work, the fifth switch K5 is turned on and conducts.

[0085] In this embodiment, when the battery protection unit 220 outputs a protection signal, for example, when the current protection unit 221 or the voltage protection unit protects the battery 110, the main switch unit 240 is disconnected and the power supply to the system circuit 300 is cut off. At this time, the current on the main switch unit 240 is 0, and there is no need to perform current detection. In order to further reduce power consumption, the current detection unit 210 is controlled not to work at this time. This is beneficial to reduce power consumption and also to prevent current detection errors (for example, in the case of charging switch 241 and discharging switch 242). When the current protection unit 221 does not protect the battery 110, whether the current detection unit 210 works is controlled by the first communication terminal CS0 signal.

[0086] Preferably, in this embodiment, the battery protection circuit 200 further includes an enable control unit 262, which is connected to the third communication terminal CSEN0 and the output terminals (current protection unit 221 and voltage protection unit) of the battery protection unit 220. When the battery protection unit 220 performs charging protection or discharging protection on the battery 110 (the battery protection unit 220 outputs a charging protection signal or a discharging protection signal), the main control unit controls the charging switch to open or close the discharging switch accordingly. At the same time, the enable control unit 262 knows from the battery protection unit whether it is charging protection or discharging protection. The enable control unit controls whether the current detection unit 210 stops working according to the charging and discharging state of the battery. Specifically, when the battery is in discharge protection mode, if the battery is not in a charging state, the enable control unit controls the current detection unit 210 to stop working; if the battery is in a charging state, the enable control unit 262 does not control the current detection unit 210 to stop working. Conversely, when the battery is in charge protection mode, if the battery is not in a discharging state, the enable control unit controls the current detection unit 210 to stop working; if the battery is in a discharging state, the enable control unit 262 does not control the current detection unit 210 to stop working. In this embodiment, the enable control unit knows whether the battery is charging or discharging based on the sign of the current sampling information. Furthermore, in other embodiments of this application, the enable control unit can also know whether the battery is charging or discharging through the main control unit. In this embodiment, the enable control unit 262 is implemented using logic gates such as AND gates, OR gates, and NOT gates.

[0087] In addition, in other embodiments of this application, it can also be implemented in other ways. For example, when the current sampling tube is a charging switch 241, if the enable control unit 262 receives a charging protection signal (e.g., charging overcurrent protection, overcharge protection, etc.), the enable control unit 262 controls the current detection unit 210 to be in a non-working state. If the enable control unit 262 receives a discharge protection signal (e.g., discharge overcurrent protection, over-discharge protection, etc.), the enable control unit 262 does not control the current detection unit 210 to be in a non-working state. At this time, it is controlled by the signal of the third communication terminal CSEN0. When the current sampling tube is a discharge switch 242, if the enable control unit 262 receives a discharge protection signal, the enable control unit 262 controls the current detection unit 210 to be in a non-working state. If the enable control unit 262 receives a charging protection signal, the enable control unit does not control the current detection unit 210 to be in a non-working state. At this time, it is controlled by the signal of the third communication terminal CSEN0. When the battery protection unit 220 does not protect the battery 110 (outputs a normal signal), the enable control unit 262 controls whether the current detection unit 210 is in working state according to the signal of the third communication terminal CSEN0.

[0088] In this embodiment, the battery protection circuit 200 is fabricated on the same semiconductor substrate, i.e., on the same chip. At this time, the power supply terminal VDD is the power supply pin, and the power ground terminal GND is the power ground pin. However, this application is not limited to this. In other embodiments of this application, the components of the battery protection circuit 200, except for the main switch unit 240 and the first image transistor MK1, are located on the first integrated circuit chip, while the main switch unit 240 and the first image transistor MK1 are located on the second integrated circuit chip. That is, the first integrated circuit chip is fabricated on one semiconductor substrate, and the second integrated circuit chip is fabricated on another semiconductor substrate. Here, the first integrated circuit chip and the second integrated circuit chip are packaged into a single product. In this embodiment, the second communication terminal CS1 and the fourth communication terminal CSEN1 can be terminals of the processor. However, this application is not limited to this. In other embodiments of this application, the second communication terminal CS1 and the fourth communication terminal CSEN1 can also be terminals of other units of the system circuit 300. Furthermore, in this embodiment, the conversion resistor Rz itself does not require high precision and has a low cost. In other embodiments of this application, the conversion resistor Rz can be external, that is, as a peripheral device of the chip. In this case, by adjusting the resistance value of the conversion resistor Rz, the magnitude of the second current information can be further adjusted so that the output information is within the detection range of the system circuit 300.

[0089] In this embodiment, the current information required by the current protection unit 221 is conventional technology in the field. For example, the current protection unit 221 is connected to the system VM to obtain information on the current flowing through the main switch. The current protection unit 221 needs to obtain the current information flowing through the main switch unit 240 in real time. Therefore, in this embodiment, the current protection unit 221 cannot use the current sampling information or the second current information, which will not be described in detail here.

[0090] 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 212, 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.

[0091] 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.

[0092] 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.

[0093] 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. An energy-saving battery protection circuit, characterized in that, include: The system includes a power supply terminal, a power ground terminal, a main control unit, and a main switch unit. The power supply terminal and the power ground terminal are used to connect to the battery. 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 to control whether the line between the battery and the system circuit is conductive. A current detection unit is used to obtain current sampling information, which is used to characterize the current flowing through the main switching unit. The current detection unit is also used to process the current sampling information to obtain second current information. A first communication terminal is connected to the current detection unit to obtain second current information. The first communication terminal is also connected to the system circuit to transmit the second current information to the system circuit. The third communication terminal is used to connect to the system circuit, and the third communication terminal is used to control whether at least some units of the current detection unit work according to the signal of the system circuit.

2. The battery protection circuit according to claim 1, characterized in that, When the third communication terminal receives the second signal sent by the system circuit, the current detection unit is in working state, and then the first communication terminal outputs the second current information to the system circuit. When the third communication terminal receives the first signal sent by the system circuit, at least some units of the current detection unit are controlled to switch to a non-operating state, wherein the second signal is used to indicate that the system circuit needs to obtain the second current information, and the first signal is used to indicate that the system circuit does not need to obtain the second current information.

3. The battery protection circuit according to claim 2, characterized in that, The time it takes for the third communication terminal to receive the second signal per unit time is less than the time it takes to receive the first signal; or, The ratio of the time it takes for the third communication terminal to receive the second signal to the time it takes to receive the first signal per unit time is less than or equal to 1:

5.

4. The battery protection circuit according to claim 1, characterized in that, The battery protection circuit also includes a battery protection unit, which is connected to the main control unit. When the battery protection unit determines that the battery charging or discharging is abnormal, it outputs a protection signal to the main control unit, and the main control unit controls the main switch unit to disconnect and cut off. The battery protection circuit further includes an enable control unit, which is connected to the third communication terminal and the battery protection unit. When the enable control unit receives a first signal or a protection signal, the enable control unit controls at least some units of the current detection unit to be in a non-operating state.

5. The battery protection circuit of claim 4, wherein, The protection signals include charging protection signals and discharging protection signals; When the enabling control unit receives a charging protection signal, it controls at least a portion of the current detection unit to be in an inactive state during battery charging; or... When the enable control unit receives a discharge protection signal, it controls at least some units of the current detection unit to be in a non-operating state during battery discharge.

6. The battery protection circuit of claim 4, wherein, The protection signals include charging protection signals and discharging protection signals. The main switching unit includes a current sampling tube, which is used to control whether charging or discharging occurs. The current detection unit includes a first mirror tube, which is mirrored with the current sampling tube. The battery protection circuit also includes an enable control unit, which is connected to the battery protection unit and the third communication terminal. When the enable control unit receives a charging protection signal or a discharging protection signal, the enable control unit is also used to control whether at least some units of the current detection unit work according to the current sampling tube.

7. The battery protection circuit according to any one of claims 1 to 5, wherein The current detection unit includes a current sampling unit and a processing unit. The current sampling unit is connected in series with the system circuit and is used to output current sampling information. The processing unit is connected to the current sampling unit, the first communication terminal and the third communication terminal. The processing unit is used to convert the current sampling information into second current information. The enable terminal of the processing unit is connected to the third communication terminal to control whether the processing unit works through the system circuit.

8. The battery protection circuit according to any one of claims 1 to 6, wherein The current detection unit includes a current sampling unit and a processing unit. The main switching unit includes a current sampling tube, which is connected in series with the system circuit. The current sampling unit includes a first mirror tube, which forms a current mirror with the current sampling tube to obtain current sampling information. The first image transistor is connected to the first end of the current sampling transistor, the control end of the first image transistor is connected to the control end of the current sampling transistor, and the second end of the first image transistor is used to output current sampling information. The current sampling unit further includes a second operational amplifier and a matching transistor. The two input terminals of the second operational amplifier are respectively connected to the second terminal of the first image transistor and the second terminal of the current sampling transistor. The second terminal of the first image transistor is also connected to the first terminal of the matching transistor. The second terminal of the matching transistor is connected to the processing unit. The control terminal of the matching transistor is connected to the output terminal of the second operational amplifier. The processing unit is used to convert the current sampling information into second current information. The enable terminal of the second operational amplifier is connected to the third communication terminal so that the current detection unit is in a non-operating state when the second operational amplifier is not working.

9. The battery protection circuit of claim 8, wherein, The processing unit includes a fourth switch, a second mirror transistor, and a switching resistor. The fourth switch is connected in series with the matching transistor, the second mirror transistor and the fourth switch form a current mirror, the switching resistor is connected in series with the second mirror transistor, and the second current information is the voltage across the switching resistor. It also includes a fifth switch, the control terminal of which is connected to the third communication terminal. The fifth switch is connected to the control terminal of the second mirror tube or connected in series with the second mirror tube. When the third communication terminal is used to control the current detection unit to be in a non-working state according to the signal of the system circuit, the fifth switch is used to control the second mirror tube to disconnect or to control the branch where the second mirror tube is located to disconnect.

10. The battery protection circuit of claim 9, wherein, The switching resistor is an external component of the chip where the remaining part of the processing unit is located.

11. The battery protection circuit according to any one of claims 1-6, characterized in that, The current detection unit includes a current sampling unit, which includes a sampling resistor connected in series with the main switching unit. The current sampling information is the voltage across the sampling resistor; or... The current detection unit includes a current sampling unit, which in turn includes a main switching unit. The current sampling information is the voltage across the main switching unit; or... The battery protection circuit is located on the same chip.

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

13. An electronic device, comprising: include: The system circuit includes a second communication terminal and a fourth communication terminal; The battery protection circuit as described in any one of claims 1-11 or the battery assembly as described in claim 12; wherein The system circuit is connected to the battery via the main switch unit of the battery protection circuit; The second communication terminal is connected to the first communication terminal, and the fourth communication terminal is connected to the third communication terminal. The fourth communication terminal is used to output a first signal or a second signal to control whether at least some units of the current detection unit are working.

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