Battery protection circuit and battery

Abstract

The utility model relates to the technical field of lithium batteries, in particular to a battery protection circuit and a battery, and the battery protection circuit comprises a protection judgment sub-circuit, a temperature detection sub-circuit, an AND gate sub-circuit and a battery protection sub-circuit, wherein the protection judgment sub-circuit, the temperature detection sub-circuit and the battery protection sub-circuit are all connected with the AND gate sub-circuit, and the temperature detection sub-circuit is used for detecting the temperature of a battery body so as to judge whether the temperature is within a set temperature range; and the AND protection judgment sub-circuit controls the battery protection sub-circuit through the AND gate sub-circuit, so that the effect that the battery is forbidden to work when the temperature exceeds a set temperature range is achieved, and the problem that the battery is lack of a temperature protection function is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of lithium batteries, in particular to a battery protection circuit and a battery. Background Art

[0002] There are some technologies in the prior art that can protect the charging and discharging of batteries, but these applications all require the design of a separate circuit to collect the temperature of the battery, and then form a feedback signal to control the working state of the battery, which results in a very complex structure of the battery charging and discharging temperature protection circuit, and the detection sensitivity is also low, which is not conducive to the efficient utilization and sustainable development of energy, nor is it conducive to the integrated design of the circuit. For example, the Chinese patent application number is "CN202111054297.6", and the patent document named "A battery temperature protection circuit based on NTC" discloses the use of NTC thermistors to detect temperature, and the use of operational amplifiers and control MOS tubes to achieve over-temperature control, thereby achieving battery temperature protection, but this solution does not retain the original overvoltage and overcurrent protection circuit design, there are safety hazards, there is no communication function, and data cannot be collected in real time. Therefore, there is an urgent need for a solution to the above problems. Utility Model Content

[0003] The utility model provides a battery protection circuit and a battery, so as to solve the potential safety hazard and communication inconvenience problems existing in the solution of realizing temperature detection through an NTC thermistor.

[0004] To solve the above technical problems, the first aspect of the utility model provides a battery protection circuit, comprising a protection determination subcircuit, a temperature detection subcircuit, an AND gate subcircuit and a battery protection subcircuit; wherein the protection determination subcircuit and the temperature detection subcircuit are respectively connected to the input end of the AND gate subcircuit, and the output end of the AND gate subcircuit is connected to the battery protection subcircuit.

[0005] Further, the battery protection subcircuit includes a first field effect transistor and a second field effect transistor; the AND gate subcircuit includes a first AND gate unit and a second AND gate unit; wherein the input end of the first AND gate unit is respectively connected to the first output end of the protection determination subcircuit and the output end of the temperature detection subcircuit, and the output end of the first AND gate unit is connected to the gate of the first field effect transistor; the input end of the second AND gate unit is respectively connected to the second output end of the protection determination subcircuit and the output end of the temperature detection subcircuit, and the output end of the second AND gate unit is connected to the gate of the second field effect transistor; the drain of the first field effect transistor is connected to the drain of the second field effect transistor; the source of the first field effect transistor is connected to the signal input end of the protection determination subcircuit; and the source of the second field effect transistor is connected to the ground voltage end of the temperature detection subcircuit.

[0006] Furthermore, the battery protection circuit further includes a first resistor, and the protection determination subcircuit is connected in series with the first resistor.

[0007] Furthermore, the battery protection circuit also includes a first capacitor, and the protection determination subcircuit is connected in parallel with the first capacitor.

[0008] Furthermore, the battery protection circuit further includes a second capacitor and a third capacitor, and the second capacitor and the third capacitor are connected in series and then connected in parallel with the battery protection sub-circuit.

[0009] Furthermore, the battery protection circuit also includes a second resistor, and the detection connection end of the protection determination subcircuit is connected to the source of the second field effect transistor via the second resistor.

[0010] Furthermore, the battery protection circuit further includes a fourth capacitor and a fifth capacitor, one end of the fourth capacitor and the fifth capacitor connected in series is connected to the input voltage end of the protection determination subcircuit, and the other end is grounded.

[0011] Furthermore, an input voltage terminal of the temperature detection subcircuit is connected to the fourth capacitor.

[0012] A second aspect of the utility model provides a battery, which includes a power source and the battery protection circuit described in the first aspect.

[0013] The utility model provides a battery protection circuit and a battery, wherein the battery protection circuit comprises a protection determination subcircuit, a temperature detection subcircuit, an AND gate subcircuit and a battery protection subcircuit; wherein the protection determination subcircuit, the temperature detection subcircuit and the battery protection subcircuit are all connected to the AND gate subcircuit, and the temperature detection subcircuit of the utility model is used to detect the temperature of the battery body to determine whether it is within a set temperature range, and control the battery protection subcircuit through the AND gate subcircuit with the protection determination subcircuit, so as to achieve the effect of prohibiting the battery from working when the set temperature range is exceeded, and the temperature detection subcircuit can be used to modify the working temperature range of the protection board according to the actual application scenario, thereby overcoming the defect that the temperature can only be redesigned when the temperature cannot be met, retaining the battery protection subcircuit, avoiding the safety hazard caused by too low or too high temperature, and making the circuit have both temperature protection and electrical performance protection functions. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a structural diagram of a battery protection circuit 10 provided in an embodiment of the utility model;

[0015] Figure 2 It is a specific connection diagram of the battery 100 provided in the embodiment of the utility model;

[0016] Figure 3It is a structural diagram of a battery 100 provided in an embodiment of the present utility model. DETAILED DESCRIPTION

[0017] The following is a detailed explanation of the implementation mode of the present invention in conjunction with the accompanying drawings. The embodiments are provided for illustrative purposes only and cannot be understood as limitations on the present invention. The accompanying drawings are provided for reference and illustration only and do not constitute limitations on the scope of patent protection of the present invention, because many changes can be made to the present invention without departing from the spirit and scope of the present invention.

[0018] In the description of the present invention, it should be understood that the terms "upper", "lower", "left", "right", "top", "middle", "bottom", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0019] refer to Figure 1-Figure 2 In a first aspect, the utility model provides a battery protection circuit 10, such as Figure 1 As shown, it includes a protection determination subcircuit 1, a temperature detection subcircuit 2, an AND gate subcircuit 3 and a battery protection subcircuit 4; wherein the protection determination subcircuit 1 and the temperature detection subcircuit 2 are respectively connected to the input end of the AND gate subcircuit 3, and the output end of the AND gate subcircuit 3 is connected to the battery protection subcircuit 4. Specifically, the utility model uses the temperature detection subcircuit 2 to detect the temperature of the battery to determine whether it is within the set temperature range, and the protection determination subcircuit 1 controls the battery protection subcircuit 4 through the AND gate subcircuit 3, so as to achieve the effect of prohibiting the battery from working when the set temperature range is exceeded, and the temperature detection subcircuit 2 can modify the working temperature range of the protection board according to the actual application scenario, overcoming the defect that the temperature can only be redesigned when the temperature cannot be met, retaining the battery protection subcircuit 4, avoiding the safety hazards caused by too low or too high temperature, so that the circuit has both temperature protection and electrical performance protection functions.

[0020] In one embodiment, the battery protection subcircuit 4 includes a first field effect transistor and a second field effect transistor; the AND gate subcircuit 3 includes a first AND gate unit and a second AND gate unit; the specific connection relationship between the subcircuits is as follows: Figure 2 As shown, in Figure 2 In the figure, CELL is the power supply 20, U1 is the protection determination subcircuit 1, U2 is the temperature detection subcircuit 2, J1 is the interface (connector), Q1 is the battery protection subcircuit 4, and U3 and U4 form an AND gate subcircuit 3; wherein,

[0021] The input end of the first AND gate unit is respectively connected to the first output end DO of the protection determination subcircuit 1 and the output end TOUT of the temperature detection subcircuit 2, and the output end of the first AND gate unit is connected to the gate of the first field effect transistor; the input end of the second AND gate unit is respectively connected to the second output end CO of the protection determination subcircuit 1 and the output end TOUT of the temperature detection subcircuit 2, and the output end of the second AND gate unit is connected to the gate of the second field effect transistor; the drain of the first field effect transistor is connected to the drain of the second field effect transistor; the source of the first field effect transistor is connected to the signal input end VIN of the protection determination subcircuit 1; the source of the second field effect transistor is connected to the ground voltage end VSS of the temperature detection subcircuit 2.

[0022] In this embodiment, the present application controls the battery protection subcircuit 4 through the temperature detection subcircuit 2 and the protection determination subcircuit 1. When the temperature detection subcircuit 2 and the protection determination subcircuit 1 input to the AND gate subcircuit 3 are both high levels, the battery protection subcircuit 4 has no protection action, and the protection board works normally. In other cases, the protection board stops working. The battery protection circuit 10 designed in this application can avoid safety hazards caused by too low or too high temperature, and has temperature protection and electrical performance protection functions at the same time.

[0023] In one embodiment, the temperature detection subcircuit 2 is connected to the control board of the terminal device through an interface, thereby realizing the communication function to adjust the temperature parameters of the temperature detection subcircuit 2; the temperature detection subcircuit 2 can also set the battery operating temperature range through the upper computer software, and the range is limited according to the actual application and will not be elaborated here.

[0024] The battery protection circuit 10 further includes a first resistor R1, and the protection determination subcircuit 1 is connected in series with the first resistor R1; the battery protection circuit 10 further includes a first capacitor C1, and the protection determination subcircuit 1 is also connected in parallel with the first capacitor C1; the battery protection circuit 10 further includes a second capacitor C2 and a third capacitor C3, and the second capacitor C2 and the third capacitor C3 are connected in series and connected in parallel with the battery protection subcircuit 4; the battery protection circuit 10 further includes a second resistor R2, and the detection connection terminal VM of the protection determination subcircuit 1 is connected to the source of the second field effect transistor through the second resistor R2; the battery protection circuit 10 further includes a fourth capacitor C4 and a fifth capacitor C5, and one end of the fourth capacitor C4 and the fifth capacitor C5 are connected in series with the input voltage terminal VDD of the protection determination subcircuit 1, and the other end is grounded; the input voltage terminal VDD of the temperature detection subcircuit 2 is connected to the fourth capacitor C4; wherein, the additional devices such as resistors and capacitors in the battery protection circuit 10 are designed to protect the battery protection board and the existing circuit, and their specific values ​​are adjusted according to actual conditions, and are not specifically limited here.

[0025] In addition, the temperature detection subcircuit 2 can also output the result pin through hardware, and when the temperature detection subcircuit 2 detects that the battery body temperature is within the set working range, the hardware output pin is low level (set to "0"); when the temperature detection module detects that the battery body temperature is outside the set working range, the hardware output pin is high level (set to "1"); the present application has the effect of prohibiting the battery from working when the set temperature range is exceeded, and the temperature detection subcircuit 2 can modify the protection board working temperature range according to the actual application scenario. The protection determination subcircuit 1 is the original protection circuit of the battery protection board - the protection circuit chip. It is high level (set to "1") when it is determined to be protected, and low level (set to "0") when it is determined not to be protected. The AND gate subcircuit 3 combines the result outputs of the temperature detection subcircuit 2 and the protection determination subcircuit 1, and outputs 1 only when both are 1, and outputs 0 in all other cases. The battery protection subcircuit 4 performs protection action or normal working action according to the output result of the AND gate subcircuit 3. When the output of the AND gate subcircuit 3 is 0, a protection action is taken to stop the protection board from working. When the output of the AND gate subcircuit 3 is 1, there is no protection action and the protection board works normally.

[0026] Among them, the AND gate subcircuit 3 only plays a judgment role. Only when the temperature is within the range and the protection board is not working normally can the field effect tube MOS be turned on and the circuit can work normally. Sequence: temperature judgment and continuous output (through the TOUT pin of the temperature detection subcircuit 2) and protection IC output (through the DO and CO pins of the protection judgment subcircuit 1) → AND gate judgment and output → MOS is turned on or off. The present application adds a temperature detection subcircuit 2 with a communication function, which can modify the operating temperature range of the protection board according to the actual application scenario, overcoming the defect that it can only be redesigned when the temperature cannot be met; and retains the battery protection subcircuit 4 to avoid safety hazards caused by too low or too high temperature, so that the battery protection circuit 10 designed in this application has both temperature protection and electrical performance protection (electrical performance protection: overvoltage, undervoltage, overcurrent, short circuit, etc.) functions.

[0027] It should be noted that the design of the AND gate sub-circuit is not unique. It only needs to satisfy the normal operation of the protection board when the protection judgment is 1 (1 means not executed) and the temperature detection result is also 1 (1 means not executed); the battery protection sub-circuit can also adopt switch control, IC control and other methods.

[0028] The second aspect of the utility model provides a battery 100, the structure of the battery 100 is as follows Figure 3As shown, it includes a power supply 20 and the battery protection circuit 10 described in the first aspect; wherein the positive electrode of the power supply 20 is respectively connected to the input voltage terminal VDD of the protection determination subcircuit 1 and the temperature detection subcircuit 2, and the negative electrode of the power supply 20 is connected to the ground voltage terminal VSS of the protection determination subcircuit 1 and the temperature detection subcircuit 2; the power supply 205 provides voltage to each subcircuit so that the circuit can operate normally.

[0029] The utility model embodiment provides a battery protection circuit, a protection determination subcircuit, a temperature detection subcircuit, an AND gate subcircuit and a battery protection subcircuit; wherein the protection determination subcircuit, the temperature detection subcircuit and the battery protection subcircuit are all connected to the AND gate subcircuit. The temperature detection subcircuit of the utility model is used to detect the temperature of the battery body to determine whether it is within a set temperature range, and control the battery protection subcircuit through the AND gate subcircuit with the protection determination subcircuit, so as to achieve the effect of prohibiting the battery from working when the set temperature range is exceeded. The temperature detection subcircuit can modify the operating temperature range of the protection board according to the actual application scenario, thereby overcoming the defect that the temperature can only be redesigned when the temperature cannot be met, retaining the battery protection subcircuit, avoiding the safety hazard caused by too low or too high temperature, and making the circuit have both temperature protection and electrical performance protection functions.

[0030] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited by the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principle of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A battery protection circuit, characterized in that: The invention comprises a protection determination subcircuit, a temperature detection subcircuit, an AND gate subcircuit and a battery protection subcircuit; wherein the protection determination subcircuit and the temperature detection subcircuit are respectively connected to the input end of the AND gate subcircuit, and the output end of the AND gate subcircuit is connected to the battery protection subcircuit; the battery protection subcircuit comprises a first field effect transistor and a second field effect transistor; the AND gate subcircuit comprises a first AND gate unit and a second AND gate unit; wherein the input end of the first AND gate unit is respectively connected to the first output end of the protection determination subcircuit and the output end of the temperature detection subcircuit, and the output end of the first AND gate unit is connected to the gate of the first field effect transistor; the input end of the second AND gate unit is respectively connected to the second output end of the protection determination subcircuit and the output end of the temperature detection subcircuit, and the output end of the second AND gate unit is connected to the gate of the second field effect transistor; the drain of the first field effect transistor is connected to the drain of the second field effect transistor; the source of the first field effect transistor is connected to the signal input end of the protection determination subcircuit; the source of the second field effect transistor is connected to the ground voltage end of the temperature detection subcircuit.

2. A battery protection circuit according to claim 1, characterized in that: The battery protection circuit further includes a first resistor, and the protection determination subcircuit is connected in series with the first resistor.

3. A battery protection circuit according to claim 1, characterized in that: The battery protection circuit further includes a first capacitor, and the protection determination subcircuit is connected in parallel with the first capacitor.

4. A battery protection circuit according to claim 1, characterized in that: The battery protection circuit further includes a second capacitor and a third capacitor, which are connected in series and then connected in parallel with the battery protection sub-circuit.

5. A battery protection circuit according to claim 1, characterized in that: The battery protection circuit further includes a second resistor, and the detection connection end of the protection determination subcircuit is connected to the source of the second field effect transistor via the second resistor.

6. A battery protection circuit according to claim 2, characterized in that: The battery protection circuit further includes a fourth capacitor and a fifth capacitor, wherein one end of the fourth capacitor and the fifth capacitor are connected in series to the input voltage end of the protection determination subcircuit, and the other end is grounded.

7. A battery protection circuit according to claim 6, characterized in that: The input voltage terminal of the temperature detection subcircuit is connected to the fourth capacitor.

8. A battery, characterized in that: The battery comprises a power source and a battery protection circuit as claimed in any one of claims 1 to 7.

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