WO2023169065A1

WO2023169065A1 - Charging and discharging protection apparatus for battery pack, battery pack and electronic device

Info

Publication number: WO2023169065A1
Application number: PCT/CN2022/144198
Authority: WO
Inventors: 李雪
Original assignee: Oppo广东移动通信有限公司
Priority date: 2022-03-07
Filing date: 2022-12-30
Publication date: 2023-09-14
Also published as: CN114640155A

Abstract

A charging and discharging protection apparatus for a battery pack, a battery pack and an electronic device. The battery pack comprises a plurality of charging and discharging branches (100) in parallel connection, and each charging and discharging branch (100) comprises a battery cell (Bat). The charging and discharging protection apparatus (200) comprises: protection switches (210) provided corresponding to each charging and discharging branch (100), the protection switches (210) each being configured to control a battery cell (Bat) to charge during forward conduction, and to control the battery cell (Bat) to discharge during reverse conduction; and protection chips (220) provided corresponding to each protection switch (210), the protection chips (220) each being configured to control the forward conduction or the reverse conduction of a protection switch (210), and to adjust the charging or discharging current of a corresponding charging and discharging branch (100) by controlling the conduction resistance of the protection switch (210).

Description

Charge and discharge protection devices for battery packs, battery packs and electronic equipment

Cross-references to related applications

This disclosure claims priority to the Chinese patent application with application number 202210217375.8, titled "Charge and Discharge Protection Device for Battery Packs, Battery Packs and Electronic Equipment" submitted on March 7, 2022, the entire content of which is incorporated herein by reference. Public.

Technical field

The present disclosure relates to the technical field of battery charging and discharging, and in particular, to a charging and discharging protection device for a battery pack, a battery pack and electronic equipment.

Background technique

In the design of lithium battery packs for mobile phones, a battery protection board or BMS (Battery Management System) must be used. The protection IC (Integrated Circuit Chip) is generally controlled by back-to-back MOS (field effect transistor) tubes. By switching on and off, the charge and discharge protection of the battery cells in the battery pack can be realized to avoid improper use of the battery cells, which may cause short circuit of the battery cells, accelerated aging due to over-discharge, or bulging of the battery pack due to overcharge.

At present, some protection ICs not only integrate charge and discharge protection functions, but also integrate reset functions. As shown in Figure 1, in the parallel battery charging architecture, one of the protection ICs also reserves a control signal line AP_CTRL1/AP_CTRL2. When one of the batteries reaches the full charge condition, the AP end pulls up the corresponding AP_CTRL1/AP_CTRL2. Control the corresponding protection IC to reset. At this time, the path between the battery core and the charging management chip is cut off, and the battery core cannot be charged or discharged.

In a parallel battery cell architecture, if the impedances from the charge management chip to each battery cell are not equal or the battery cell capacity is greatly different, when one of the battery cells is fully charged in advance due to large current shunt or small battery cell capacity, although the protection IC can be controlled through Reset to stop the charging and discharging of the battery core, so that all the current output by the charging management chip is input to the under-full battery core for charging, but this will have the following problems: (1) the battery core cannot be fully charged simultaneously; (2) for high-voltage In the power charging scheme, the battery cells that have reached the fast full charge condition first will have their power reduced and enter the normal low-power charging. This will cause the battery cells that have not reached the fast full charge condition to be charged by the normal charge. If all the battery cells reach the Under full charge conditions, the overall charging time will be extended because the battery cell that reaches the fast full charge condition first returns to fast charging; (3) When the battery cell current difference is too large, the battery cell with large shunt may exceed the battery cell magnification. If the user Unplugging the adapter during charging will cause the battery cell voltage deviation to be too large. If the user continues to use it, the battery cells with low voltage will trigger the system shutdown first, causing the battery cells with high voltage to lose capacity.

In related technologies, current limiting ICs are added to adjust the current in the charging and discharging paths of the battery cells. As shown in Figure 2, adding a current limiting IC between the charging management chip and the battery pack can control the charging and discharging of each battery cell separately. The impedance of the LOADSWITCH (electronic load) of the path is used to adjust the shunt size of each cell to achieve the purpose of solving the above problems. However, this method will not only increase the circuit volume and cost, but also generate additional heat.

public content

The present disclosure aims to solve one of the technical problems in the related art, at least to a certain extent. To this end, the first purpose of the present disclosure is to propose a charge and discharge protection device for a battery pack, which integrates the current limiting and charge and discharge protection functions by multiplexing the protection switch, which can not only realize the charge and discharge protection of the battery core, but also In addition, the path current of the battery core can be indirectly controlled by controlling the on-resistance of the protection switch to limit the path current. This can effectively avoid excessive differences in the path current of the battery core without increasing the circuit volume, cost, heat, etc. This may lead to problems such as the inability of batteries to be fully charged simultaneously.

The second object of the present disclosure is to provide a battery pack.

The third object of the present disclosure is to provide an electronic device.

In order to achieve the above object, the first embodiment of the present disclosure proposes a charge and discharge protection device for a battery pack. The battery includes a plurality of charge and discharge branches connected in parallel. Each charge and discharge branch includes a battery core. The charge and discharge protection device It includes: a protection switch set corresponding to each charging and discharging branch. The protection switch is configured to control the battery core to charge when conducting forward and to control the battery core to discharge when conducting reverse conducting. A protection chip corresponding to each protection switch is configured to protect the battery. The chip is configured to control the forward conduction or reverse conduction of the protection switch, and adjust the charge and discharge current of the corresponding charge and discharge branch by controlling the conduction resistance of the protection switch.

According to the charge and discharge protection device of the battery pack according to the embodiment of the present disclosure, the current limiting and charge and discharge protection functions are integrated by multiplexing the protection switch, which can not only realize the charge and discharge protection of the battery core, but also control the conduction of the protection switch. The pass impedance indirectly controls the path current of the battery core and realizes the current limit of the path current. This can effectively avoid the failure of the battery core to be fully charged simultaneously due to the excessive difference in the path current of the battery core without increasing the circuit volume, cost and heat. Waiting questions.

According to one embodiment of the present disclosure, the protection chip is further configured to adjust the charging current of the corresponding charging and discharging branches when the protection switch is forward-conducted, so that the cells of the multiple charging and discharging branches reach full conditions at the same time.

According to one embodiment of the present disclosure, the protection chip is further configured to maintain balance in the battery cells of the multiple charge and discharge branches by adjusting the discharge current of the corresponding charge and discharge branch when the protection switch is reversely conductive.

According to an embodiment of the present disclosure, when the battery pack is charging, the on-resistance of the protection switch is adjusted in proportion to the charging current of the corresponding charging and discharging branch, and is adjusted in proportion to the battery capacity of the corresponding charging and discharging branch.

According to an embodiment of the present disclosure, when the battery pack is discharging, the on-resistance of the protection switch is adjusted inversely proportionally to the battery capacity of the corresponding charging and discharging branch.

According to one embodiment of the present disclosure, the protection chip communicates with the application processor to receive the impedance adjustment instruction issued by the application processor according to the charge and discharge current of the charge and discharge branch and/or the battery capacity.

According to an embodiment of the present disclosure, the protection switch adopts a back-to-back MOS tube design.

According to an embodiment of the present disclosure, the back-to-back MOS transistor includes a first MOS transistor and a second MOS transistor. The source of the first MOS transistor is connected to the negative terminal of the cell in the charge and discharge branch, and the drain of the first MOS transistor is connected to the negative terminal of the battery cell in the charge and discharge branch. The drain of the second MOS transistor is connected, the source of the second MOS transistor is connected to the negative electrode of the battery pack, the gate of the first MOS transistor and the gate of the second MOS transistor are respectively connected to the first drive output terminal and the second drive output terminal of the protection chip. The drive output terminals are connected accordingly.

In order to achieve the above object, a second embodiment of the present disclosure provides a battery pack, including the aforementioned battery pack charge and discharge protection device.

According to the battery pack according to the embodiment of the present disclosure, the aforementioned charge and discharge protection device is used to integrate the current limiting and charge and discharge protection functions by multiplexing the protection switch, which can not only realize the charge and discharge protection of the battery core, but also control the protection The on-resistance of the switch indirectly controls the path current of the cell to limit the path current, thereby effectively avoiding failure of the cell due to excessive differences in cell path current without increasing circuit volume, cost, heat, etc. Issues such as synchronization and full charging.

In order to achieve the above object, a third embodiment of the present disclosure provides an electronic device, including the aforementioned charge and discharge protection device of a battery pack.

According to the electronic equipment of the embodiment of the present disclosure, the aforementioned charge and discharge protection device is used to integrate the current limiting and charge and discharge protection functions by multiplexing the protection switch, which can not only realize the charge and discharge protection of the battery core, but also control the protection The on-resistance of the switch indirectly controls the path current of the cell to limit the path current, thereby effectively avoiding failure of the cell due to excessive differences in cell path current without increasing circuit volume, cost, heat, etc. Issues such as synchronization and full charging.

Additional aspects and advantages of the disclosure will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the disclosure.

Description of the drawings

Figure 1 shows a parallel cell charging architecture in related technologies;

Figure 2 shows another parallel cell charging architecture in related technology;

Figure 3 is a schematic structural diagram of a charge and discharge protection device for a battery pack according to an embodiment of the present disclosure;

Figure 4 is a circuit schematic diagram of a charge and discharge protection device for a battery pack according to an embodiment of the present disclosure.

Detailed ways

Embodiments of the present disclosure are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present disclosure and are not to be construed as limitations of the present disclosure.

The charge and discharge protection device, battery pack and electronic equipment of the battery pack proposed by the embodiments of the present disclosure will be described below with reference to the accompanying drawings.

Figure 3 is a schematic structural diagram of a charge and discharge protection device for a battery pack according to an embodiment of the present disclosure.

Referring to FIG. 3 , the battery pack includes a plurality of charge and discharge branches 100 connected in parallel, and each charge and discharge branch 100 includes a battery cell Bat. That is to say, the present disclosure is mainly applied in parallel cell architecture.

The charge and discharge protection device 200 includes: a protection switch 210 provided corresponding to each charge and discharge branch 100. The protection switch 210 is configured to control the battery cell Bat to charge when the forward conduction is conducted, and to control the battery cell Bat to discharge when the reverse conduction is conducted; correspondingly Each protection switch 210 is provided with a protection chip 220. The protection chip 220 is configured to control the forward conduction or reverse conduction of the protection switch 210, and adjust the charge and discharge of the corresponding charge and discharge branch 100 by controlling the conduction resistance of the protection switch 210. current.

Specifically, when the battery pack needs to be charged, the positive and negative poles P+ and P- of the battery pack are connected to the positive and negative poles of the external DC power supply. At the same time, each protection chip 220 controls the corresponding protection switch 210 to conduct forward based on the charging command. , so that the external DC power supply charges each battery cell Bat. During the charging process, when the battery cell Bat is overcharged or the charging and discharging branch 100 where it is located suffers from short circuit or overcurrent or other abnormal conditions, the protection chip 220 corresponding to the battery cell Bat will control the corresponding protection switch 210 to open. Realize the charging protection of the battery cell Bat; when the charging current of the charge and discharge branch 100 where a certain battery cell Bat is located is too different from the charging current of the charge and discharge branch 100 of other battery cells Bat, the corresponding battery cell Bat The protection chip 220 will control the on-resistance of the corresponding protection switch 210 based on the current limiting requirement to adjust the charging current of the charging and discharging branch 100 where the battery cell Bat is located to avoid the problem that the battery cells cannot be fully charged simultaneously due to excessive current differences. question.

When the battery pack needs to be discharged, the positive and negative electrodes P+ and P- of the battery pack are connected to the positive and negative power supply terminals of the external load. At the same time, each protection chip 220 controls the corresponding protection switch 210 to conduct reverse conduction based on the discharge command, so that each battery The core Bat supplies power to the external load. During the power supply process, when the battery cell Bat is over-discharged or the charging and discharging branch 100 where it is located suffers from short circuit or overcurrent or other abnormal conditions, the protection chip 220 corresponding to the battery cell Bat will control the corresponding protection switch 210 to open. Realize the discharge protection of the battery cell Bat; when the discharge current of the charge and discharge branch 100 where a certain battery cell Bat is located and the discharge current of the charge and discharge branch 100 of other battery cells Bat are too different, the corresponding battery cell Bat The protection chip 220 will control the on-resistance of the corresponding protection switch 210 based on the current limiting requirement to adjust the discharge current of the charging and discharging branch 100 where the battery cell Bat is located to avoid capacity loss of some battery cells due to excessive current differences. question.

In the above embodiment, the current limiting and charge and discharge protection functions are integrated by multiplexing the protection switch, which not only realizes the charge and discharge protection of the battery core, but also indirectly controls the path current of the battery core by controlling the conduction resistance of the protection switch. , effectively avoiding problems such as the inability to fully charge the cells simultaneously due to excessive current differences in the cell paths, while not increasing circuit volume, cost, or additional heat.

In some embodiments, the protection chip 220 is also configured to adjust the charging current of the corresponding charging and discharging branches 100 when the protection switch 210 is forward-conducted, so that the battery cells Bat of the multiple charging and discharging branches 100 are fully charged at the same time. condition.

Furthermore, when the battery pack is being charged, the on-resistance of the protection switch 200 is adjusted in proportion to the charging current of the corresponding charging and discharging branch 100, and is adjusted in proportion to the battery capacity of the corresponding charging and discharging branch 100.

Specifically, as shown in Figure 3, when the battery pack needs to be charged, each protection chip 220 controls the forward conduction of the corresponding protection switch 210 based on the charging command, and at the same time controls the conduction resistance of the protection switch 210. In the initial state, each The on-resistance of the protection switch 210 is basically the same, so that the external DC power supply starts charging each battery cell Bat.

During the charging process, the charging current of each charging and discharging branch 100 and the power of each battery cell Bat are obtained and judged. If the difference between the charging currents of any two charging and discharging branches 100 is within the preset current range, and the difference in the electric power of any two battery cells Bat is within the preset electric power range, then the protection switch 210 of each protection switch 210 is maintained. The conduction resistance remains unchanged; if the charging current of a certain charging and discharging branch 100 is too large (or too small), it may be because the impedance of the charging and discharging branch 100 is too small (or too large), causing the shunt to be too large ( or too small), at this time, the protection chip 220 corresponding to the charge and discharge branch 100 increases (or decreases) the on-resistance of the corresponding protection switch 210 to reduce (or increase) the charge and discharge branch 100 The charging current is such that the difference between the charging current of the other charging and discharging branches 100 is within the preset current range; if the power of a certain battery cell Bat is too high (or too low), it means that the battery cell Bat has an advance ( or lag) is fully charged. At this time, the protection chip 220 corresponding to the battery cell Bat increases (or decreases) the on-resistance of the corresponding protection switch 210 to reduce (or increase) the charge location of the battery cell Bat. The charging current of the discharging branch 100 makes the difference between the electric power of this battery cell Bat and the electric power of other battery cells Bat fall within the preset electric power range. Repeatedly adjusting in this way until charging is completed can make the cells Bat of multiple charging and discharging branches 100 reach full conditions at the same time.

Therefore, during the charging process, based on the charging current of the charging and discharging branches and the power of the battery cells, by adjusting the on-resistance of the protection switch, the battery cells of multiple charging and discharging branches can reach full conditions at the same time.

In some embodiments, the protection chip 220 is further configured to balance the battery cells of the multiple charging and discharging branches 100 by adjusting the discharge current of the corresponding charging and discharging branches 100 when the protection switch 210 is reversely conductive.

Furthermore, when the battery pack is discharging, the on-resistance of the protection switch 210 is adjusted inversely proportionally to the battery capacity of the corresponding charging and discharging branch 100 .

Specifically, as shown in Figure 3, when the battery pack needs to be discharged, each protection chip 220 controls the reverse conduction of the corresponding protection switch 210 based on the discharge command, and at the same time controls the conduction resistance of the protection switch 210. In the initial state, each The on-resistance of the protection switch 210 is basically the same, so that each battery cell Bat starts to supply power to the external load.

During the discharge process, the power of each battery cell Bat is obtained and judged. If the difference between the electric power of any two battery cells Bat is within the preset electric power range, the on-resistance of each protection switch 210 is kept unchanged; if the electric power of a certain battery cell Bat is too high (or too low), It means that the discharge of the battery cell Bat is too slow (or too fast). At this time, the protection chip 220 corresponding to the battery cell Bat adjusts the conduction resistance of the corresponding protection switch 210 to increase (or decrease). The discharge current of the charging and discharging branch 100 where the battery cell Bat is located increases (reduces) the discharge speed of the battery cell Bat, so that the difference between the power of the battery cell Bat and the power of other battery cells Bat is within the preset power range. . Such repeated adjustments can keep the battery cells in the multiple charging and discharging branches 100 balanced until the discharge is completed.

Therefore, during the discharge process, based on the power of the battery core, by adjusting the on-resistance of the protection switch, the battery power of multiple charging and discharging branches can be balanced to avoid the loss of battery power.

In some embodiments, the protection chip 220 communicates with the application processor to receive the impedance adjustment instructions issued by the application processor according to the charging and discharging current of the charging and discharging branch 100 and/or the battery capacity.

Specifically, during the charging process of the battery pack, each protection chip 220 can obtain the charging current of each charge and discharge branch 100 and the power of each battery cell Bat, and send them to the application processor, and the application processor will control each charge and discharge branch. The charging current of the circuit 100 and the power of each battery cell Bat are judged, and an impedance adjustment instruction is generated and sent to the protection chip 220 that needs impedance adjustment, so that the protection chip 220 adjusts the conduction resistance of the corresponding protection switch 210 according to the impedance adjustment instruction. The details can be as mentioned above and will not be described again here.

During the discharge process of the battery pack, each protection chip 220 can obtain the power of each battery cell Bat and send it to the application processor. The application processor will judge the power of each battery cell Bat and generate an impedance adjustment instruction to send to the impedance required. The protection chip 220 is adjusted so that the protection chip 220 adjusts the on-resistance of the corresponding protection switch 210 according to the impedance adjustment instruction. The details are as described above and will not be described again here.

As a result, the charge and discharge control of the battery pack can be realized through the application processor.

In some embodiments, the protection switch 210 adopts a back-to-back MOS transistor design.

Optionally, as shown in Figure 4, the back-to-back MOS tubes include: a first MOS tube M1 and a second MOS tube M2. The source of the first MOS tube M1 is connected to the negative terminal of the battery cell Bat in the charge and discharge branch 100. The drain of the first MOS transistor M1 is connected to the drain of the second MOS transistor M2, the source of the second MOS transistor M2 is connected to the negative electrode P- of the battery pack, and the gate of the first MOS transistor M1 is connected to the gate of the second MOS transistor M2. The gates are respectively connected to the first driving output terminal DO and the second driving output terminal CO of the protection chip 220 . Among them, the first MOS transistor M1 and the second MOS transistor M2 both have body diodes.

It should be noted that based on the on-resistance-gate-source voltage characteristics of the MOS tube, it can be known that the on-resistance is inversely proportional to the gate-source voltage, that is, the higher the gate-source voltage, the higher the on-resistance. Therefore, by controlling the gate voltage of the MOS tube, the on-resistance of the MOS tube can be indirectly controlled, thereby controlling the charge and discharge current of the charge and discharge branch.

Specifically, referring to FIG. 4 , the protection chip 220 can communicate with the application processor through an I2C communication interface (including a clock interface SCL and a bidirectional data transmission interface SDA).

When the battery pack needs to be charged, the application processor sends a charging command to each protection chip 220 through the I2C communication interface. Based on the charging command, each protection chip 220 controls the corresponding second MOS transistor M2 to be turned on, and controls the first MOS transistor M1 to be turned off. On, due to the action of the body diode of the first MOS transistor M1, the protection switch 210 is forward-conducting at this time, and the protection chip 220 controls the gate voltage of the second MOS transistor M2 to control the conduction resistance of the second MOS transistor M2. Initially In this state, the conduction resistance of each second MOS transistor M2 is basically the same.

During the charging process, each protection chip 220 detects the charging current of the corresponding charging and discharging branch 100 through the current detection port Isense, and obtains the power of the corresponding battery cell Bat by reading the voltage of the power supply terminal VDD, and sends it to the application processor. The application processor determines the charging current of each charging and discharging branch 100 and the power of each battery cell Bat. If the difference in charging current of any two charging and discharging branches 100 is within the preset current range, and any two If the difference in the battery capacity of the battery cell Bat is within the preset power range, the application processor will not process it.

If the charging current of a certain charging and discharging branch 100 is too large (or too small), it means that the impedance of the charging and discharging branch 100 is too small (or too large), causing the shunt to be too large (or too small). When the application processor generates an impedance adjustment instruction corresponding to the charge and discharge branch 100 and sends it to the corresponding protection chip 220, the protection chip 220 decreases (or increases) the gate voltage of the corresponding second MOS transistor M2 based on the impedance adjustment instruction. , to increase (or decrease) the on-resistance of the corresponding second MOS transistor M2 to reduce (or increase) the charging current of the charging and discharging branch 100 to make it consistent with the charging of other charging and discharging branches 100 The difference in current is within the preset current range.

If the power of a certain battery cell Bat is too high (or too low), it means that the battery cell Bat has the possibility of being filled early (or lagging). At this time, the application processor generates the impedance adjustment command corresponding to the battery cell Bat and sends it. To the corresponding protection chip 220, the protection chip 220 decreases (or increases) the gate voltage of the corresponding second MOS transistor M2 based on the impedance adjustment instruction to increase (or decrease) the gate voltage of the corresponding second MOS transistor M2. The impedance is passed to reduce (or increase) the charging current of the charging and discharging branch 100 where the battery cell Bat is located, so that the difference between the power of the battery cell Bat and the power of other battery cells Bat is within the preset power range. Repeatedly adjusting as above can make the battery cells Bat of multiple charging and discharging branches 100 reach full conditions at the same time.

Considering that the capacity of each battery cell Bat is not completely consistent, even after current limiting processing, some battery cells Bat may still be fully charged in advance. At this time, the corresponding second MOS transistor M2 can be controlled to turn off, and the first MOS transistor can be controlled. When M1 is turned on, it stops charging the battery cell Bat that has been fully charged in advance, but retains the discharge capability of the battery cell Bat in order to achieve voltage balance.

During the charging process, each protection chip 220 also performs short-circuit protection, overcharge current protection, etc. based on the obtained charging current of the corresponding charge and discharge branch 100, and at the same time performs overcharge voltage protection based on the obtained power of the battery cell Bat.

When the battery pack needs to be discharged, the application processor sends a discharge command to each protection chip 220 through the I2C communication interface. Based on the discharge command, each protection chip 220 controls the corresponding first MOS transistor M1 to be turned on, and controls the second MOS transistor M2 to be turned off. On, due to the action of the body diode of the second MOS transistor M2, the protection switch 210 conducts in the reverse direction at this time. At the same time, the protection chip 220 controls the gate voltage of the first MOS transistor M1 to control the conduction resistance of the first MOS transistor M1. Initially In this state, the conduction resistance of each first MOS transistor M1 is basically the same.

During the discharging process, each protection chip 220 obtains the power of the corresponding battery cell Bat by reading the voltage of the power supply terminal VDD, and sends it to the application processor. The application processor determines the power of each battery cell Bat. If the difference in power between any two battery cells Bat is within the preset power range, the application processor does not process it.

If the power of a certain battery cell Bat is too high (or too low), it means that the battery cell Bat is discharging too slowly (or too fast). At this time, the application processor generates the impedance adjustment command corresponding to the battery cell Bat and sends it to the corresponding The protection chip 220 of the protection chip 220 increases (or decreases) the gate voltage of the first MOS transistor M1 based on the impedance adjustment instruction to decrease (or increase) the on-resistance of the first MOS transistor M1 to increase the (or reduce) the discharge current of the charging and discharging branch 100 where the battery cell Bat is located, and increase (reduce) the discharge speed of the battery cell Bat, so that the difference between the power of the battery cell Bat and the power of other battery cells Bat is at Within the preset battery range. Repeatedly adjusting as above can keep the battery cells in the multiple charging and discharging branches 100 balanced.

During the discharge process, each protection chip 220 also performs short-circuit protection, over-discharge current protection, etc. based on the obtained discharge current of the corresponding charge and discharge branch 100, and at the same time performs over-discharge voltage protection based on the obtained power of the battery cell Bat.

In addition, when an abnormal situation such as a crash occurs in the protection chip 220, it can also be forced to reset through the reset port RESET.

In the above embodiment, by integrating the current limiting function on the protection chip and reusing the protection switch, not only the charging and discharging protection of the battery core can be realized, but also the synchronous full charging of the battery core can be realized, effectively avoiding the problem of battery failure caused by the battery core. Excessive difference in channel current leads to problems such as the inability of the cells to be fully charged simultaneously. At the same time, it can save costs and motherboard layout area.

In summary, according to the charge and discharge protection device according to the embodiment of the present disclosure, the current limiting and charge and discharge protection functions are integrated by multiplexing the protection switch, which can not only protect the battery core, but also control the protection switch. The on-resistance is used to indirectly control the path current to achieve current limiting in the battery path, thus avoiding problems such as the inability to fully charge the battery simultaneously due to excessive current differences in the battery path. At the same time, there is no additional hardware circuit, which reduces hardware cost, volume and Fever issues, etc.

In some embodiments, embodiments of the present disclosure also provide a battery pack including the above charge and discharge protection device.

According to the battery pack in the embodiment of the present disclosure, the aforementioned charge and discharge protection device is used to integrate the current limiting and charge and discharge protection functions by multiplexing the protection switch, which not only realizes the charge and discharge protection of the battery core, but also can The on-resistance of the protection switch indirectly controls the path current of the battery core and realizes the current limit of the path current. This can effectively prevent the battery core from being damaged due to excessive difference in the path current of the battery core without increasing the circuit volume, cost, heat, etc. Problems such as being unable to synchronize full charging, etc.

In some embodiments, embodiments of the present disclosure also provide an electronic device, which includes the above-mentioned battery pack.

In the description of this specification, reference to the terms "one embodiment," "some embodiments," "an example," "specific examples," or "some examples" or the like means that specific features are described in connection with the embodiment or example. , structures, materials, or features are included in at least one embodiment or example of the present disclosure. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

In addition, the terms “first” and “second” are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of indicated technical features. Therefore, features defined as "first" and "second" may explicitly or implicitly include at least one of these features. In the description of the present disclosure, "plurality" means at least two, such as two, three, etc., unless otherwise expressly and specifically limited.

In this disclosure, unless otherwise explicitly stated and limited, the terms "installation", "connection", "connection", "fixing" and other terms should be understood in a broad sense. For example, it can be a fixed connection or a detachable connection. , or integrated into one; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be an internal connection between two elements or an interactive relationship between two elements, unless otherwise specified restrictions. For those of ordinary skill in the art, the specific meanings of the above terms in this disclosure can be understood according to specific circumstances.

Although the embodiments of the present disclosure have been shown and described above, it can be understood that the above-mentioned embodiments are illustrative and should not be construed as limitations of the present disclosure. Those of ordinary skill in the art can make modifications to the above-mentioned embodiments within the scope of the present disclosure. The embodiments are subject to changes, modifications, substitutions and variations.

Claims

A charge and discharge protection device for a battery pack. The battery pack includes a plurality of charge and discharge branches connected in parallel. Each of the charge and discharge branches includes a battery core. The charge and discharge protection device includes:

A protection switch is provided corresponding to each of the charging and discharging branches, and the protection switch is configured to control the battery core to charge when the forward conduction is conducted, and to control the battery core to discharge when the reverse conduction is conducted;

A protection chip is provided corresponding to each of the protection switches. The protection chip is configured to control the forward conduction or reverse conduction of the protection switch, and adjust the corresponding charge and discharge branch by controlling the conduction resistance of the protection switch. charge and discharge current.
The charge and discharge protection device of the battery pack according to claim 1, wherein the protection chip is further configured to adjust the charging current of the corresponding charge and discharge branch when the protection switch is forward-conducting, so that the plurality of all The cells of the above charging and discharging branches reach the full condition at the same time.
The charge and discharge protection device of the battery pack according to claim 1, wherein the protection chip is further configured to adjust the discharge current of the corresponding charge and discharge branch when the protection switch is reversely conductive, so that the plurality of all The battery cells in the above charging and discharging branches are kept balanced.
The charge and discharge protection device of the battery pack according to any one of claims 1 to 3, wherein when the battery pack is charging, the conduction resistance of the protection switch is proportional to the charging current of the corresponding charge and discharge branch. Adjust, and adjust in proportion to the battery power of the corresponding charge and discharge branch.
The charge and discharge protection device of the battery pack according to any one of claims 1 to 3, wherein when the battery pack is discharging, the conduction resistance of the protection switch follows the battery capacity of the corresponding charge and discharge branch. Inverse proportional adjustment.
The charge and discharge protection device of the battery pack according to any one of claims 1 to 3, wherein the protection chip communicates with the application processor to receive the charging information of the application processor according to the charge and discharge branch. Impedance adjustment instructions issued by discharge current and/or cell power.
The charge and discharge protection device of the battery pack according to any one of claims 1 to 3, wherein the protection switch adopts a back-to-back MOS tube design.
The charge and discharge protection device of the battery pack according to claim 7, wherein the back-to-back MOS tubes include a first MOS tube and a second MOS tube, and the source of the first MOS tube is connected to the charge and discharge branch. The negative terminal of the battery core, the drain of the first MOS tube is connected to the drain of the second MOS tube, the source of the second MOS tube is connected to the negative terminal of the battery pack, the first MOS The gate electrode of the tube and the gate electrode of the second MOS tube are respectively connected to the first driving output terminal and the second driving output terminal of the protection chip.
A battery pack including the charge and discharge protection device of the battery pack according to any one of claims 1 to 8.
Electronic equipment, including the charge and discharge protection device of the battery pack according to any one of claims 1-8.