Battery pack protection chip, circuit and system

Abstract

The application discloses a battery pack protection chip, which comprises a maximum voltage judging module, a circuit protection detecting module, a circuit protection judging module, a delay module and a driving module; the maximum voltage judging module is used for judging the maximum voltage according to the voltage detected by the multi-stage battery voltage detecting end of the battery pack protection chip and outputting a judging signal; and the circuit protection detecting module is used for outputting a first detecting signal, a second detecting signal and a third detecting signal according to the voltage detected by the multi-stage battery voltage detecting end. The application provides a chip for a battery pack protection circuit, the voltage of the battery after being connected to the circuit is judged through the setting of the maximum voltage judging module and the circuit protection judging module, the protection is not triggered before the battery pack is completely connected to the circuit, the false triggering of the disconnection protection caused by the connection of a specific battery is avoided, the arbitrary order connection of elements to the chip provided by the application is realized, and no peripheral resistance needs to be arranged in the protection circuit, so that the cost is effectively reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electronics, in particular to a battery pack protection chip, a battery pack protection circuit and a battery pack protection system. BACKGROUND

[0002] The basic function of the multi-section battery chip protection system is overcharge protection and disconnection protection. However, in the related art, when the battery pack and the battery protection system circuit board are assembled, the connection sequence of each single battery and the protection system circuit board cannot be fixed. In order to avoid triggering the fuse during assembly, a specific sequence needs to be followed during assembly. In order to achieve the intended technical purpose, two peripheral resistors need to be added in addition to the protection chip. SUMMARY

[0003] The present application provides a battery pack protection chip, a battery pack protection circuit and a battery pack protection system.

[0004] The battery pack protection chip of the present application comprises a maximum voltage judgment module, a circuit protection detection module, a circuit protection judgment module, a delay module and a driving module.

[0005] The maximum voltage judgment module is used to judge the maximum voltage according to the voltage detected by the multi-stage battery voltage detection end of the battery pack protection chip and output a judgment signal. The multi-stage battery voltage detection end is connected to the multiple batteries in the battery pack from the negative electrode to the positive electrode in turn. The multi-stage battery voltage detection end is connected in turn in a predetermined sequence to detect the voltage of the corresponding connected battery in the battery pack.

[0006] The circuit protection detection module is used to output a first detection signal, a second detection signal and a third detection signal according to the voltage detected by the multi-stage battery voltage detection end.

[0007] The circuit protection judgment module is used to output a first control signal and a second control signal according to the judgment signal and the first detection signal.

[0008] The delay module is used to output a delay signal according to the first control signal and the second detection signal.

[0009] The driving module is used to output a driving signal according to the third detection signal, the second control signal and the delay signal, so as to realize the overcharge protection and disconnection protection of the battery pack.

[0010] Therefore, the application provides a chip for a battery pack protection circuit, which judges the voltage of the battery after being connected to the circuit through the highest voltage judging module and the circuit protection judging module, and does not trigger protection before the battery pack is completely connected to the circuit, thereby avoiding the false triggering of the line break protection caused by the connection of a specific battery, and realizing the arbitrary sequence connection of elements. In addition, the chip provided by the application does not need to additionally set a peripheral resistance element in the protection circuit, thereby effectively reducing the cost.

[0011] In some embodiments, the highest voltage judging module comprises a voltage drop unit and a judging unit, the voltage drop unit is connected to multiple levels of the battery voltage detection end and the first power supply end of the battery pack protection chip, and the judging unit is connected to multiple levels of the battery voltage detection end and the first power supply end.

[0012] In some embodiments, the voltage drop unit comprises multiple diodes corresponding to multiple levels of the battery voltage detection end, the negative poles of the multiple diodes are connected to the first power supply end, and the positive poles of the multiple diodes are connected to the corresponding battery voltage detection end.

[0013] In some embodiments, the chip comprises a power supply voltage module, the power supply voltage module is connected to the first power supply end of the battery pack protection chip, and the power supply voltage module is used to supply power to the circuit in the battery pack protection chip.

[0014] In some embodiments, the second power supply end of the chip is used to connect the negative pole of the battery pack.

[0015] The application also provides a battery pack protection circuit, which comprises:

[0016] The battery pack protection chip as described above;

[0017] A protection sub-circuit, which is connected to the driving signal end of the battery pack protection chip and the positive voltage end and the negative voltage end of the battery pack protection circuit, and is used to disconnect the connection between the battery pack and the positive voltage end according to the driving signal output by the driving signal end.

[0018] In some embodiments, the protection sub-circuit comprises a three-terminal fuse and a switching element, the switching element is connected to the driving signal end, the negative voltage end, the second power supply end of the battery pack protection chip and the first end of the three-terminal fuse, the second end of the three-terminal fuse is connected to the positive voltage end, and the third end of the three-terminal fuse is connected to the first power supply end of the battery pack protection chip.

[0019] In some embodiments, the switch element comprises a transistor, a gate of the transistor is connected to the driving signal end, a first pole of the transistor is connected to the negative voltage end and the second power supply end, and a second pole of the transistor is connected to the first end of the three-terminal fuse.

[0020] The application also provides a battery protection system, comprising:

[0021] A battery pack comprising a plurality of batteries;

[0022] A battery protection circuit as described above.

[0023] In some embodiments, the battery pack comprises a plurality of switches, and the plurality of switches are respectively connected to a plurality of battery voltage detection ends and the second power supply end of the battery protection chip.

[0024] Additional aspects and advantages of the embodiments of the application will be in part apparent and in part pointed out hereinafter. BRIEF DESCRIPTION OF DRAWINGS

[0025] The above and / or additional aspects and advantages of the application will become apparent and be readily appreciated from the following description, including the drawings, in which:

[0026] Figure 1 is a module schematic diagram of the battery protection chip provided by the application;

[0027] Figure 2 is a module schematic diagram of the battery protection chip in the prior art;

[0028] Figure 3 is a structure schematic diagram of the highest voltage judgment module in the battery protection chip provided by the application;

[0029] Figure 4 is a partial circuit structure schematic diagram of the circuit protection judgment module in the battery protection chip provided by the application;

[0030] Figure 5 is a structure schematic diagram of the battery protection system provided by the application. DETAILED DESCRIPTION

[0031] The embodiments of the technical solutions of the application will be described in detail below with reference to the drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the application, and therefore only serve as examples, and cannot limit the protection scope of the application.

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of this application; the use of the terms "including," "comprising," or "having" and variations thereof herein is intended to be broad and encompass the terms "consisting of" and "consisting essentially of" and variations thereof. Unless otherwise required by context, singular terms shall include pluralities and vice versa. Unless otherwise required by context, the use herein of the singular is also to be construed as a use of the plural and vice versa.

[0033] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise explicitly specified.

[0034] Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearance of the phrase in various places in the specification does not necessarily all refer to the same embodiment, nor is it necessarily independent or alternative embodiments to each other. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0035] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the three cases of A alone, A and B together, and B alone. In addition, the character " / " in this paper generally represents that the front and rear associated objects are a "or" relationship.

[0036] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two), and similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0037] In the description of the embodiments of the present application, unless otherwise explicitly specified and limited, the technical terms "mounting", "connecting", "connecting", "fixing" and the like should be broadly understood, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanical connection, or it can be electrical connection; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0038] Please refer to Figure 1The application provides a battery pack protection chip, which comprises a maximum voltage judging module, a circuit protection detecting module, a circuit protection judging module, a delay module and a driving module.

[0039] The maximum voltage judging module is used for judging the maximum voltage according to the voltage detected by the multi-stage battery voltage detecting end of the battery pack protection chip and outputting a judging signal.

[0040] The circuit protection detecting module is used for outputting a first detecting signal, a second detecting signal and a third detecting signal according to the voltage detected by the multi-stage battery voltage detecting end.

[0041] The circuit protection judging module is used for outputting a first control signal and a second control signal according to the judging signal and the first detecting signal.

[0042] The delay module is used for outputting a delay signal according to the first control signal and the second detecting signal.

[0043] The driving module is used for outputting a driving signal according to the third detecting signal, the second control signal and the delay signal, so as to realize the overcharge protection and the disconnection protection of the battery pack.

[0044] Specifically, the battery pack protection chip is a core integrated circuit for realizing the protection of the battery pack, and is mainly used for judging the current state of the battery pack and executing the protection action according to the judging result. Figure 2 As shown in the prior art, the chip modular structure specifically comprises a power supply system module, a circuit protection detecting module, a delay module and a driving module. The power supply system module is directly connected with an external power supply and directly leads the input signal to the delay module. The circuit protection detecting module directly detects the voltage of each battery, obtains the second detecting signal and the third detecting signal through logical calculation, and inputs the second detecting signal and the third detecting signal to the delay module and the driving module respectively. The delay module receives the input signal and the second detecting signal, determines a delay signal processed through delay, and inputs the delay signal to the driving module. The third detecting signal and the delay signal are logically calculated to obtain a driving signal, and the output pin is driven to realize the protection function under the control of the driving signal. However, the above technical scheme has the technical problems that the jump-off protection may be triggered at any time, the peripheral elements need to be added, and the installation sequence has rigid requirements.

[0045] Therefore, the application is improved on the basis of the above technical scheme, as shown in Figure 1As shown in the above scheme, the highest voltage judgment module is improved on the basis of the power supply system module, and is mainly used for controlling the voltage drop generated at both ends of the battery pack to avoid the occurrence of the line break protection when the assembly is not completed. In addition, the highest voltage judgment module is also used for judging whether the voltage at the input pin of the chip is the highest voltage of the chip, and generating and transmitting a judgment signal. The circuit protection detection module adds an output of a first detection signal on the basis of the above scheme, and the first detection signal is mainly used for cooperating with the circuit protection judgment module of the newly added chip. The circuit protection judgment module is a new module newly added to the battery pack protection chip, and mainly performs signal judgment on whether the line break protection is triggered. The circuit protection judgment module mainly performs logical operation on the judgment signal and the first detection signal related to the line break protection generated by the circuit protection detection module, obtains two groups of control signals, and inputs a second control signal to the driving module and a first control signal to the delay module. After receiving the first control signal and the second detection signal, the delay module uses logical operation to delay the signals to obtain a delay signal and input the delay signal to the driving module. The driving module determines the final driving signal according to the received first control signal, delay signal and third detection signal, and controls the high and low levels of the driving signal end according to the driving signal to control the elements outside the chip to complete the protection action.

[0046] In some embodiments, as shown in Figure 3 The highest voltage judgment module includes a voltage drop unit and a judgment unit. The voltage drop unit is connected to the multi-stage battery voltage detection end and the first power supply end of the battery pack protection chip. The judgment unit is connected to the multi-stage battery voltage detection end and the first power supply end. The first power supply end is used for connecting the positive electrode of the battery pack.

[0047] Specifically, the functions of the highest voltage judgment module are implemented by two parallel units. The voltage drop unit and the judgment unit are connected in parallel between the multi-stage battery voltage detection end and the first power supply end VCC. The voltage drop unit is mainly responsible for controlling the voltage drop generated at both ends of each battery of the battery pack when the battery is connected to the chip to avoid triggering the line break protection during assembly. The judgment unit judges whether the input voltage of the voltage detection end is the highest voltage of the chip according to the voltage size, so as to monitor and execute the line break protection after the assembly is completed. The multi-stage battery voltage detection end corresponds to the pins VC1, VC2, VCn-1 and VCn in the chip, and is respectively connected to the positive electrodes of the corresponding batteries V1, V2, Vn-1 and Vn. The first power supply end VCC is generally connected to the positive electrode of the battery pack.

[0048] In some embodiments, as shown in Figure 3 The voltage drop unit includes a plurality of diodes corresponding to the multi-stage battery voltage detection end. The negative electrodes of the plurality of diodes are connected to the first power supply end, and the positive electrodes of the plurality of diodes are respectively connected to the corresponding battery voltage detection ends.

[0049] Specifically, the method for the voltage drop unit to generate voltage drop when the battery pack connection chip is implemented is that for each battery in the battery pack, a diode is led out from the positive electrode and connected to the first power supply end of the chip. The negative electrode of each diode is connected to the first power supply end, and the positive electrode is connected to the positive electrode of the corresponding battery. For example, battery V1 corresponds to diode D1, battery V2 corresponds to diode D2, and battery Vn corresponds to diode Dn. In this way, n batteries correspond to n parallel diodes, forming an n-diode array. Therefore, the voltage value at the first voltage end must be lower than the sum of the voltages connected to the VCn pins in the chip, and the voltage difference at each pin is equal to the on-voltage drop of the diode connected to the pin. Therefore, the voltage at the first power supply end, i.e., the VCC pin, must not be the highest voltage of the chip in this case, so the open circuit protection will not be triggered, ensuring that the open circuit protection will not be triggered during assembly.

[0050] In addition, the determination unit determines the determination signal according to whether the voltage at the first power supply end VCC is the highest and the connection state of each battery to determine whether to trigger the open circuit protection. In some examples, not all batteries in the battery pack are connected during assembly, which will be identified as a situation that triggers the open circuit protection. However, since the voltage at the first power supply end must be lower than the voltage of the connected battery, the open circuit protection determination module can determine that the open circuit detection is not effective according to the logical operation, thereby avoiding the false triggering of the open circuit protection during assembly.

[0051] In some embodiments, the chip includes a power supply voltage module connected to the first power supply end of the battery pack protection chip, and the power supply voltage module is used to supply power to the circuit in the battery pack protection chip.

[0052] Specifically, although the first power supply end VCC is connected to the functional unit in the highest voltage determination module, the output voltage appears in the form of a signal, and the power supply problem of the chip has not been substantially solved. Therefore, a power supply voltage module connected to the first power supply end VCC is separately provided to receive external power supply and supply power to other elements in the chip that are not directly connected to the battery pack and elements connected to the battery pack but have additional power demand, ensuring the normal operation of the chip in the circuit. In some examples, as shown in Figure 4 As shown, the circuit protection determination module is powered by the power supply system module, and the highest voltage determination module is also powered by the power supply system module.

[0053] In some embodiments, the second power supply end of the chip is used to connect the negative electrode of the battery pack.

[0054] Specifically, in order to constitute a complete circuit to make the whole circuit produce effects, it is necessary to determine the negative connection point of the battery pack. In some examples, the second power supply end of the chip, i.e. the VSS end, is connected to the negative pole of the battery pack. Generally, in order to ensure the safety of the circuit, the second power supply end VSS is generally grounded, thus also ensuring the convenience of calculation and monitoring of the potential of each point in the circuit.

[0055] As shown in Figure 5 The application also provides a battery pack protection circuit, comprising:

[0056] The battery pack protection chip as described in the above embodiments;

[0057] A protection sub-circuit connected to the driving signal end of the battery pack protection chip, the positive voltage end and the negative voltage end of the battery pack protection circuit, the protection sub-circuit being configured to disconnect the battery pack from the positive voltage end according to the driving signal output by the driving signal end.

[0058] Specifically, the protection sub-circuit is a sub-circuit in the battery pack protection circuit for implementing disconnection protection, which mainly realizes disconnection protection of the battery pack by forming a group of elements for disconnection through controlled action according to the driving signal finally output by the battery pack protection chip, such as air switches, electronic fuses and the like. The positive voltage end P+ and the negative voltage end P- are the external load ends of the whole battery pack protection circuit.

[0059] In some embodiments, the protection sub-circuit comprises a three-terminal fuse and a switching element, the switching element being connected to the driving signal end, the negative voltage end, the second power supply end of the battery pack protection chip and the first end of the three-terminal fuse, the second end of the three-terminal fuse being connected to the positive voltage end, and the third end of the three-terminal fuse being connected to the first power supply end of the battery pack protection chip.

[0060] Specifically, in some examples, a three-terminal fuse is selected as the core functional component of the protection sub-circuit, and a switching element serves as the working switch of the protection sub-circuit to control the working state of the three-terminal fuse in the circuit. For the three-terminal fuse, the second end and the third end are connected to the fuse, and the first end is connected to the heating element in the three-terminal fuse. When the switching element is turned on and the driving signal end of the battery pack protection chip outputs a high level, the current drives the heating element to heat and melt the fuse of the second end and / or the third end, thus opening the circuit and realizing disconnection protection. At the same time, the three-terminal fuse is also directly connected to the positive pole of the battery pack and the positive voltage end P+ of the circuit load, so that the three-terminal fuse can still melt the protection circuit when the load is short-circuited.

[0061] In some embodiments, the switching element comprises a transistor, the gate of the transistor being connected to the driving signal end, the first pole of the transistor being connected to the negative voltage end and the second power supply end, and the second pole of the transistor being connected to the first end of the three-terminal fuse.

[0062] Specifically, the switch element is a transistor, in some examples, a MOS tube NM1, the source of the MOS tube NM1 is connected to the negative voltage end P- and the second power supply end VSS, the gate is connected to the driving output end CO, and the drain is connected to the first end of the three-terminal fuse. When the MOS tube NM1 is turned on, the first end of the three-terminal fuse is directly connected to the driving output end CO, at which time the protection sub-circuit normally works; when the MOS tube NM1 is turned off, the protection sub-circuit is in an open circuit state, but the fuse between the second end and the third end of the three-terminal fuse is still connected between the battery pack and the load, and can provide fuse protection for the circuit load.

[0063] The application also provides a battery pack protection system, comprising:

[0064] a battery pack comprising a plurality of batteries;

[0065] a battery pack protection circuit as described above.

[0066] In some embodiments, the battery pack comprises a plurality of switches, and the plurality of switches are respectively connected to the plurality of battery voltage detection ends and the second power supply end of the battery pack protection chip.

[0067] Specifically, as shown in Figure 5 the internal circuit of the battery pack comprises a plurality of switches S0, S1, …, Sn-1, Sn, etc., and each switch controls the on-off of a branch. In some examples, when only S0 and S1 are closed, only one battery V1 in the battery pack is connected to the protection circuit, the second power supply end VSS of the chip is connected to the VC1 pin, Sn is disconnected at this time, and the first power supply end VCC is not normally connected. At this time, the voltage at the first power supply end VCC in the battery pack protection chip is the voltage at VC1 minus the on-voltage drop of the diode D1, that is, the voltage at the first power supply end VCC is not the highest voltage of the chip, at which time the disconnection protection is not triggered. The process of closing S2-Sn-1 is still the same, and the voltage at the first power supply end VCC is always not the highest voltage of the chip, and the disconnection protection is not triggered. Until Sn is closed, the entire battery pack is completely connected to the protection circuit, at which time the voltage at the first power supply end VCC is the highest voltage of the chip, and the disconnection protection mechanism normally operates. When the condition triggering the disconnection protection is detected, the disconnection protection mechanism is triggered, the three-terminal fuse is blown, the circuit is opened, and the disconnection protection is completed.

[0068] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than limit them. Although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that the technical solutions recorded in the foregoing embodiments can be modified, or some or all of the technical features can be replaced equivalently. Such modifications or replacements do not change the essence of the corresponding technical solutions, which should be covered in the scope of the claims and the specification of the present application. In particular, the technical features mentioned in each embodiment can be combined in any manner as long as there is no structural conflict. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery pack protection chip, characterized by, The chip comprises a highest voltage judging module, a circuit protection detecting module, a circuit protection judging module, a delay module and a driving module. The highest voltage judging module is configured to judge the highest voltage according to the voltage detected by the multi-stage battery voltage detecting terminals of the battery pack protection chip and output a judging signal. The circuit protection detecting module is configured to output a first detecting signal, a second detecting signal and a third detecting signal according to the voltage detected by the multi-stage battery voltage detecting terminals. The circuit protection judging module is configured to output a first control signal and a second control signal according to the judging signal and the first detecting signal. The delay module is configured to output a delay signal according to the first control signal and the second detecting signal. The driving module is configured to output a driving signal according to the third detecting signal, the second control signal and the delay signal, so as to realize the overcharge protection and disconnection protection of the battery pack.

2. The chip according to claim 1, characterized in that, The highest voltage judging module comprises a voltage drop unit and a judging unit.

3. The chip of claim 2, wherein, The voltage drop unit comprises a plurality of diodes corresponding to the multi-stage battery voltage detecting terminals.

4. The chip of claim 1, wherein The chip comprises a power supply voltage module.

5. The chip of claim 1, wherein The second power supply terminal of the chip is configured to connect the negative electrode of the battery pack.

6. A battery pack protection circuit, characterized by, The circuit comprises: The battery pack protection chip of any one of claims 1-5; The protection sub-circuit is configured to disconnect the connection between the battery pack and the positive voltage terminal according to the driving signal output by the driving signal terminal.

7. The circuit of claim 6, wherein, The protection sub-circuit comprises a three-terminal fuse and a switching element.

8. The circuit of claim 7, wherein, The switching element comprises a transistor.

9. A battery pack protection system, characterized by, The battery pack comprises a plurality of batteries. ​ The battery pack protection circuit according to any one of claims 6-8.

10. The system of claim 9, wherein, The battery pack comprises a plurality of switches, and the plurality of switches are connected with the plurality of battery voltage detection terminals and the second power supply terminal of the battery pack protection chip respectively.

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