Cell protection circuit, battery and terminal device

Abstract

The present disclosure relates to a battery cell protection circuit, a battery, and a terminal device. Among them, the protection circuit includes: a battery cell having a positive electrode and a negative electrode; a power circuit connected to the positive electrode and the negative electrode of the battery cell respectively, and at least one first switching unit is provided in the power circuit; a detection circuit connected to the positive electrode and the negative electrode of the battery cell respectively, and at least one second switching unit is provided in the detection circuit; a control mechanism including at least one control chip connected to the power circuit, configured to control the on / off of each of the first switching units and each of the second switching units according to at least one of the voltage and current of the power circuit. When an abnormality occurs during the charging and discharging process of the battery cell, the power circuit can be timely cut off, and the detection circuit can also be cut off when necessary, thereby further protecting the charging and discharging safety of the battery cell, avoiding dangerous situations such as overcharging, over-discharging, and short-circuiting, and preventing damage to the battery cell.

Description

Technical Field

[0001] The present disclosure relates to the technical field of terminal devices, and particularly relates to a cell protection circuit, a battery, and a terminal device. Background Art

[0002] With the progress of science and technology, the functions of terminal devices such as mobile phones are becoming more and more abundant, and the requirements for the standby and usage duration of the devices are getting higher and higher. Therefore, higher and higher requirements are put forward for the battery power and usage safety. In related technologies, a protection chip is provided in the battery of the terminal device. The protection chip can protect the battery during the charging and discharging process, and the detection function of the battery is also integrated in the protection chip, but the detection result is not accurate. Summary of the Invention

[0003] To overcome the problems existing in the related technologies, embodiments of the present disclosure provide a cell protection circuit, a battery, and a terminal device to solve the defects in the related technologies.

[0004] According to a first aspect of the embodiments of the present disclosure, a cell protection circuit is provided, including:

[0005] A cell having a positive electrode and a negative electrode;

[0006] A power circuit connected to the positive electrode and the negative electrode of the cell respectively, and at least one first switch unit is provided in the power circuit;

[0007] A detection circuit connected to the positive electrode and the negative electrode of the cell respectively, and at least one second switch unit is provided in the detection circuit;

[0008] A control mechanism including at least one control chip connected to the power circuit, configured to control the on / off of each of the first switch units and each of the second switch units according to at least one of the voltage and current of the power circuit.

[0009] In one embodiment, at least one first protection resistor is provided on the line connecting the positive electrode of the cell in the detection circuit, and at least one second protection resistor is provided on the line connecting the negative electrode of the cell in the detection circuit.

[0010] In one embodiment, each control chip is connected to one of the first switch units and / or one of the second switch units, and is configured to control the on / off of the corresponding switch unit according to at least one of the voltage and current of the power circuit.

[0011] In one embodiment, two first switch units are provided on the line in the power circuit connected to the negative electrode of the battery cell, and one second switch unit is provided on the line in the detection circuit connected to the negative electrode of the battery cell. The control mechanism includes a first control chip and a second control chip;

[0012] Wherein, the first control chip is used to control the on-off of one first switch unit and the second switch unit, and the second control chip is used to control the on-off of the other first switch unit.

[0013] In one embodiment, the second control chip includes a first detection terminal, a second detection terminal, a third detection terminal, a fourth detection terminal, a first control terminal and a second control terminal. A first resistor and a first capacitor are connected between the positive electrode and the negative electrode of the battery cell. On the power circuit, a second resistor, a third resistor and two first switch units are sequentially provided in a direction away from the negative electrode;

[0014] Wherein, the first detection terminal is connected to the line between the first resistor and the first capacitor, the second detection terminal is connected to the negative electrode of the battery cell, the third detection terminal is connected to the line between the two first switch units through a fourth resistor, the fourth detection terminal is connected to the line between the second resistor and the third resistor, and the first control terminal and the second control terminal are respectively connected to the corresponding first switch unit;

[0015] The first detection terminal, the second detection terminal and the fourth detection terminal are used to detect the voltage of the power circuit, and the third detection terminal is used to detect the current of the power circuit.

[0016] In one embodiment, the first switch unit includes two switching tubes. Wherein, the first control terminal is connected to one switching tube, the second control terminal is connected to the other switching tube, and the first control terminal and the second control terminal are respectively used to control the on-off of the corresponding switching tube.

[0017] In one embodiment, the first control chip includes a fifth detection terminal, a sixth detection terminal, a seventh detection terminal, an eighth detection terminal, a third control terminal and a fourth control terminal. The positive electrode of the battery cell is grounded through a fifth resistor and a second capacitor;

[0018] Wherein, the fifth detection terminal is connected to the line between the fifth resistor and the second capacitor, the sixth detection terminal is grounded, the seventh detection terminal is connected to the line on the side of the two first switch units away from the negative electrode of the battery cell through a sixth resistor, and the eighth detection terminal is connected to the line between the third resistor and the first switch unit;

[0019] The fifth detection terminal, the sixth detection terminal, and the eighth detection terminal are used to detect the voltage of the power circuit, and the seventh detection terminal is used to detect the current of the power circuit.

[0020] In one embodiment, the first switching unit includes two switching tubes. Among them, the third control terminal is connected to one of the switching tubes, and the fourth control terminal is connected to the other switching tube. The third control terminal and the fourth control terminal are respectively used to control the on / off of the corresponding switching tube.

[0021] In one embodiment, at least one of the third control terminal and the fourth control terminal is connected to the second switching unit to control the on / off of the second switching unit.

[0022] According to a second aspect of the embodiments of the present disclosure, a battery is provided, including the cell protection circuit according to any one of the first aspects.

[0023] According to a third aspect of the embodiments of the present disclosure, a terminal device is provided, including the battery according to the second aspect.

[0024] The technical solutions provided by the embodiments of the present disclosure may include the following beneficial effects:

[0025] The cell protection circuit provided by the present disclosure can make the detection results of the cell obtained through the detection circuit more accurate by setting an independent detection circuit in parallel with the power circuit, and switching units capable of being turned on and off are respectively provided in the power circuit and the detection circuit. Furthermore, the switching units are controlled by a control mechanism, that is, when an abnormality occurs during the charging and discharging process of the cell, the power circuit can be timely cut off, and the detection circuit can also be cut off when necessary, thereby further protecting the charging and discharging safety of the cell, avoiding dangerous situations such as overcharging, over-discharging, and short-circuiting, and preventing damage to the cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The accompanying drawings herein are incorporated into the specification and constitute a part of this specification, showing embodiments consistent with the present invention and used together with the specification to explain the principles of the present invention.

[0027] Figure 1 is a partial schematic diagram of a cell protection circuit in the related art shown in an exemplary embodiment of the present disclosure;

[0028] Figure 2 is a partial schematic diagram of the cell protection circuit shown in an exemplary embodiment of the present disclosure. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] Exemplary embodiments will be described in detail herein, and examples thereof are shown in the accompanying drawings. When the following description refers to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present disclosure. On the contrary, they are merely examples of devices and methods consistent with some aspects of the present disclosure as detailed in the appended claims.

[0030] The terms used in the present disclosure are for the purpose of describing particular embodiments only and are not intended to limit the present disclosure. The singular forms "a", "the", and "said" used in the present disclosure and the appended claims are also intended to include the plural forms unless the context clearly dictates otherwise. It should also be understood that the term "and / or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

[0031] It should be understood that although the terms first, second, third, etc. may be used in the present disclosure to describe various information, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from each other. For example, without departing from the scope of the present disclosure, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the word "if" as used herein may be interpreted as "when" or "while" or "in response to determining".

[0032] With the progress of science and technology, the functions of terminal devices such as mobile phones are becoming more and more abundant, and the requirements for the standby and usage time of the devices are getting higher and higher. Therefore, higher and higher requirements are put forward for the battery power and usage safety. In the related art, a protection chip is provided for the battery of the terminal device. The protection chip can protect the battery during the charging and discharging process, and the detection function of the battery is also integrated in the protection chip (IC). However, the detection result is not accurate.

[0033] Specifically, please refer to the appendix Figure 1 , which shows a cell protection circuit in the related art. It can be seen that it includes two protection chips (ICs) U1 and U2, and U1 integrates a dedicated cell voltage detection function. Therefore, U1 is different from U2 and becomes a BSIC. U1 is connected to the negative electrode of the cell through its BS pin to achieve accurate detection of the cell voltage. However, using a BSIC to detect the cell voltage is easily affected by the inherent function of the power loop, resulting in inaccurate detection results, and the cost of the chip integrating the cell voltage detection function is also relatively high.

[0034] Based on this, at least one embodiment of the present disclosure provides a cell protection circuit. Please refer to the appendix Figure 2, which shows a partial circuit diagram of the telecommunication protection circuit. The telecommunication protection circuit includes a battery cell 201, a power circuit 202, a detection circuit 203, and a control mechanism. Among them, the battery cell 201 has a positive electrode and a negative electrode. The power circuit 202 is respectively connected to the positive electrode and the negative electrode of the battery cell 201, and at least one first switch unit 204 is provided in the power circuit 202. The detection circuit 203 is respectively connected to the positive electrode and the negative electrode of the battery cell 201, and at least one second switch unit 205 is provided in the detection circuit 203. The control mechanism includes at least one control chip connected to the power circuit 202, which is used to control the on / off of each first switch unit 204 and each second switch unit 205 according to at least one of the voltage and current of the power circuit 202.

[0035] Among them, the power circuit 202 includes two lines, namely the line connected to the positive electrode of the battery cell 201 and the line connected to the negative electrode of the battery. The two lines respectively form two connection terminals, that is, the P+ terminal formed by the line connected to the positive electrode of the battery cell 201 and the P- terminal formed by the line connected to the negative electrode of the battery cell 201. The two connection terminals are used to connect to a load to discharge the battery cell 201, or to connect to a charger to charge the battery cell 201. During the discharge process, the current flows from the battery cell 201 to the load, and the voltage of the battery cell 201 gradually decreases. During the charging process, the current flows from the charger to the battery cell 201, and the voltage of the battery cell 201 gradually increases. During the discharge process of the battery cell 201, there is a safety threshold, that is, the lowest value of the voltage drop. If the battery continues to discharge below this voltage value, it will cause damage or potential damage to the battery cell 201. During the charging process of the battery cell 201, there is a safety threshold, that is, the maximum value of the voltage increase. If the voltage continues to increase when charging above this voltage, it will cause damage or potential damage to the battery cell 201. The first switch unit 204 can be set on one of the above lines. For example, the first switch unit 204 can be set on the line connected to the positive electrode of the battery cell 201, or on the line connected to the negative electrode of the battery. The first switch unit 204 can also be set on the above two lines, that is, at least one first switch unit 204 is set on the line connected to the positive electrode of the battery cell 201, and at least one first switch unit 204 is set on the line connected to the negative electrode of the battery cell 201 at the same time. When overcharging or over-discharging occurs in the power circuit 202, the first switch unit 204 can cut off the battery cell 201 from continuing to charge or discharge, so as to prevent the battery cell 201 from being damaged or potentially damaged due to continued charging or discharging. In addition, when a short circuit occurs in the detection circuit 203 resulting in excessive current, the first switch unit 204 can cut off the battery cell 201 from continuing to discharge or charge, so as to prevent the battery cell 201 from being damaged or potentially damaged due to the short circuit.

[0036] Among them, the detection circuit 203 includes two lines, namely the line connected to the positive electrode of the battery cell 201 and the line connected to the negative electrode of the battery. The two lines respectively form two connection terminals, namely the S+ terminal formed by the line connected to the positive electrode of the battery cell 201 and the BS terminal formed by the line connected to the negative electrode of the battery cell 201. The two connection terminals are used to connect to the detection chip, so that the detection chip can accurately detect the voltage of the battery cell 201. Moreover, when the battery cell 201 is detected for voltage by the detection chip through the detection circuit 203, it is also discharging outward, that is, the current is flowing through the detection circuit 203 to the detection chip. When the voltage of the battery cell 201 is normal and the power is sufficient, the detection chip can continuously detect, that is, the battery cell 201 can continuously discharge; but when the battery cell 201 is over-discharged, that is, the voltage is less than or equal to the safety threshold during discharge, not only the first switch unit 204 of the power circuit 202 can cut off the continuous discharge of the battery cell 201 to the load, but also the second switch unit 205 of the detection circuit 203 can cut off the continuous discharge of the battery cell 201 to the detection chip, so as to prevent the battery cell 201 from being damaged or potentially damaged due to continuous discharge. In addition, when the power circuit 202 has a short circuit resulting in an excessive current, the second switch unit 205 can cut off the continuous discharge or charging of the battery cell 201, so as to prevent the battery cell 201 from being damaged or potentially damaged due to the short circuit.

[0037] Among them, at least one control chip of the control mechanism is respectively connected to the power circuit 202. The control chip can detect the voltage and / or current at at least one place of the power circuit 202. Therefore, the control mechanism can control the on / off of each first switch unit 204 and each second switch unit 205.

[0038] In one example, each of the control chips is connected to one of the first switch units 204 and / or one of the second switch units 205, and is used to control the on / off of the corresponding switch unit according to at least one of the voltage and current of the detection circuit 203. That is to say, each control chip can control the on / off of one first switch unit 204, or control the on / off of one second switch unit 205, or control the on / off of one first switch unit 204 and one second switch unit.

[0039] The battery cell protection circuit provided in this embodiment can make the detection result of the battery cell 201 obtained through the detection circuit 203 more accurate by setting an independent detection circuit 203 in parallel with the power circuit 202. Moreover, switch units capable of being turned on and off are respectively provided in the power circuit 202 and the detection circuit 203. Furthermore, the switch units are controlled by a control mechanism, that is, when an abnormality occurs during the charging and discharging process of the battery cell 201, the power circuit 202 can be timely cut off, and the detection circuit 203 can also be cut off when necessary, thereby further protecting the charging and discharging safety of the battery cell 201 and avoiding dangerous situations such as overcharging, over-discharging, and short-circuiting, and preventing damage to the battery cell 201.

[0040] In some embodiments of the present disclosure, at least one first protection resistor RS1 is provided on the line connecting the positive electrode of the battery cell 201 in the detection circuit 203, and at least one second protection resistor RS2 is provided on the line connecting the negative electrode of the battery cell 201 in the detection circuit 203. By providing protection resistors on the two lines of the detection circuit 203, it is possible to avoid excessive current caused by a short circuit in the detection circuit 203, thereby preventing damage or potential damage to the battery cell 201 due to excessive current.

[0041] In some embodiments of the present disclosure, two first switch units 204 are provided on the line connecting the negative electrode of the battery cell 201 in the power circuit 202, and one second switch unit 205 is provided on the line connecting the negative electrode of the battery cell 201 in the detection circuit 203. The control mechanism includes a first control chip 206 and a second control chip 207; wherein, the first control chip 206 is used to control the on and off of one first switch unit 204 and the second switch unit 205, and the second control chip 207 is used to control the on and off of the other first switch unit 204.

[0042] Among them, both of the two first switch units 204 can control the on / off of the power loop 202. That is, when any one of the two first switch units 204 is in the off state, the power loop 202 will be cut off and charging and discharging cannot be performed. Only when both of the two first switch units 204 are in the connected state can the power loop 202 be turned on and charging and discharging can be performed. The two first switch units 204 are respectively controlled by the first control chip 206 and the second control chip 207, and the control logics of the first control chip 206 and the second control chip 207 are secondary control. That is, the triggering difficulty of the first control chip 206 is lower, and the triggering difficulty of the second control chip 207 is higher. For example, when overcharging occurs during the charging process, first, the first control chip 206 responds and controls the corresponding first switch unit 204 to turn off to cut off the power loop 202. However, if the first control chip 206 fails and does not control the corresponding first switch unit 204 to turn off when overcharging occurs, the battery cell 201 will continue to charge, resulting in a continuous increase in voltage. When the voltage rises to the voltage threshold corresponding to the second control chip 207, the corresponding first switch unit 204 will be controlled to turn off to cut off the power loop 202. Another example is that when over-discharging occurs during the discharging process, first, the first control chip 206 responds and controls the corresponding first switch unit 204 to turn off to cut off the power loop 202. However, if the first control chip 206 fails and does not control the corresponding first switch unit 204 to turn off when over-discharging occurs, the battery cell 201 will continue to discharge, resulting in a continuous decrease in voltage. When the voltage drops to the voltage threshold corresponding to the second control chip 207, the corresponding first switch unit 204 will be controlled to turn off to cut off the power loop 202. Another example is that when the power loop 202 is short-circuited, the current suddenly increases. The first control chip 206 responds and controls the corresponding first switch unit 204 to turn off to cut off the power loop 202. However, if the first control chip 206 fails and does not control the corresponding first switch unit 204 to turn off when a short circuit occurs, the battery cell 201 will continue to be short-circuited, resulting in a continuous increase in current. When the current rises to the voltage threshold corresponding to the second control chip 207, the corresponding first switch unit 204 will be controlled to turn off to cut off the power loop 202.

[0043] Among them, the second switch unit 205 can control the on / off of the detection circuit 203. That is, when the second switch unit 205 is in the off state, the detection circuit 203 will be cut off and unable to discharge to the detection chip. The second switch unit 205 is controlled by the first control chip 206, which is the first stage of the above secondary control. When over-discharge occurs during the discharge process, the first control chip 206 responds, not only controlling the corresponding first switch unit 204 to turn off to cut off the power circuit 202, but also simultaneously controlling the second switch unit 205 to turn off to cut off the detection circuit 203. That is to say, the battery cell 201 can neither continue to discharge through the power circuit 202 nor continue to discharge through the detection circuit 203, more thoroughly cutting off the discharge of the battery cell 201 and further increasing the safety and stability of the battery cell 201.

[0044] In some embodiments of the present disclosure, the second control chip 207 includes a first detection terminal VDD resistor, a second detection terminal VSS, a third detection terminal CS, a fourth detection terminal VM, a first control terminal CO, and a second control terminal DO. A first resistor R1 and a first capacitor 1 are connected between the positive and negative electrodes of the battery cell 201. On the detection circuit 203, a second resistor R2, a third resistor R3, and two first switch units 204 are sequentially arranged along the direction away from the negative electrode; among them, the first detection terminal VDD is connected to the line between the first resistor R1 and the first capacitor 1, the second detection terminal VSS is connected to the negative electrode of the battery cell 201, the third detection terminal CS is connected to the line between the two first switch units 204 through a fourth resistor R4, the fourth detection terminal VM is connected to the line between the second resistor R2 and the third resistor R3, and the first control terminal CO and the second control terminal DO are respectively connected to the corresponding first switch unit 204; the first detection terminal VDD, the second detection terminal VSS, and the fourth detection terminal VM are used to detect the voltage of the power circuit 202, and the third detection terminal CS is used to detect the current of the power circuit 202.

[0045] Among them, when the voltage of the detection circuit 203 is abnormal, such as too low or too high, the first detection terminal VDD and the second detection terminal VSS can detect it, so that the first control terminal CO or the second control terminal DO controls the corresponding first switch unit 204 to turn off; when the detection circuit 203 returns to normal, such as when the voltage drops back to the normal voltage or rises back to the normal voltage, the fourth detection terminal VM can detect it. For example, after the power circuit 202 is cut off due to over-discharge, if the first detection terminal VDD and the second detection terminal VSS detect that the voltage has returned to normal, the fourth detection terminal VM can also detect it and can distinguish whether the battery cell 201 automatically adjusts to the normal voltage or the normal voltage is restored because a charger is connected. The two situations correspond to two voltage thresholds. That is to say, after the fourth detection terminal VM determines the way of voltage recovery, it controls the corresponding first switch unit 204 to be connected according to the corresponding voltage threshold through the first control terminal CO or the second control terminal DO.

[0046] In some embodiments of the present disclosure, the first switch unit 204 includes two switching tubes. Among them, the first control terminal CO is connected to one of the switching tubes, the second control terminal DO is connected to the other switching tube, and the first control terminal CO and the second control terminal DO are respectively used to control the on and off of the corresponding switching tubes.

[0047] Among them, the first switch unit 204 may include two switching tubes with opposite directions, such as MOS tubes, and the two switching tubes are respectively responsible for the on and off of charging and discharging. For example, when dangerous situations such as overcharging occur during charging, the first control terminal CO controls the corresponding switching tube to turn off; when dangerous situations such as over-discharging occur during discharging, the second control terminal DO controls the corresponding switching tube to turn off.

[0048] In some embodiments of the present disclosure, the first control chip 206 includes a fifth detection terminal VDD, a sixth detection terminal VSS, a seventh detection terminal CS, an eighth detection terminal VM, a third control terminal CO, and a fourth control terminal DO. The positive electrode of the battery cell 201 is grounded through a fifth resistor R5 and a second capacitor 2; among them, the fifth detection terminal VDD is connected to the line between the fifth resistor R5 and the second capacitor 2, the sixth detection terminal VSS is grounded, the seventh detection terminal CS is connected to the line on the side of the two first switch units 204 far from the negative electrode of the battery cell 201 through a sixth resistor R6, and the eighth detection terminal VM is connected to the line between the third resistor R3 and the first switch unit 204; the fifth detection terminal VDD, the sixth detection terminal VSS, and the eighth detection terminal VM are used to detect the voltage of the power circuit 202, and the seventh detection terminal CS is used to detect the current of the power circuit 202.

[0049] Among them, when the voltage of the detection circuit 203 is abnormal, such as too low or too high, the fifth detection terminal VDD and the sixth detection terminal VSS can detect it, so that the third control terminal CO or the fourth control terminal DO controls the corresponding first switch unit 204 to turn off; when the detection circuit 203 returns to normal, such as when the voltage drops back to the normal voltage or rises back to the normal voltage, the eighth detection terminal VM can detect it. For example, when the power circuit 202 is cut off due to over-discharge, if the fifth detection terminal VDD and the sixth detection terminal VSS detect that the voltage has returned to normal, the eighth detection terminal VM can also detect it and can distinguish whether the battery cell 201 automatically adjusts to the normal voltage or returns to the normal voltage because a charger is connected. The two situations correspond to two voltage thresholds. That is to say, after the eighth detection terminal VM determines the way of voltage recovery, it controls the corresponding first switch unit 204 to be connected according to the corresponding voltage threshold through the third control terminal CO or the fourth control terminal DO.

[0050] In some embodiments of the present disclosure, the first switch unit 204 includes two switching tubes. Among them, the third control terminal CO is connected to one of the switching tubes, and the fourth control terminal DO is connected to the other switching tube. The third control terminal CO and the fourth control terminal DO are respectively used to control the on / off of the corresponding switching tubes.

[0051] Among them, the first switch unit 204 may include two switching tubes with opposite directions, such as MOS tubes, and the two switching tubes are respectively responsible for the on / off of charging and discharging. For example, when dangerous situations such as overcharging occur during charging, the third control terminal CO controls the corresponding switching tube to turn off. When dangerous situations such as over-discharging occur during discharging, the fourth control terminal DO controls the corresponding switching tube to turn off.

[0052] In some embodiments of the present disclosure, at least one of the third control terminal CO and the fourth control terminal DO is connected to the second switch unit 205 to control the on / off of the second switch unit 205.

[0053] Among them, the control terminal of the first control chip 206 and the second switch unit 205 can be connected in the following manner: if the third control terminal CO controls the corresponding switching tube to turn off during discharging, then the third control terminal CO is connected to the second switch unit 205. If the fourth control terminal DO controls the corresponding switching tube to turn off during discharging, then the fourth control terminal DO is connected to the second switch unit 205. The second switch unit 205 may include a switching tube, such as a MOS tube.

[0054] According to the second aspect of the embodiments of the present disclosure, a battery is provided, including the battery cell protection circuit described in any item of the first aspect.

[0055] Among them, the battery can supply power to terminal devices such as mobile phones.

[0056] According to a third aspect of the embodiments of the present disclosure, a terminal device is provided, including the battery described in the second aspect.

[0057] Those skilled in the art will readily conceive of other embodiments of the present disclosure after considering the specification and practicing the disclosure herein. This application is intended to cover any variations, uses, or adaptations of the present disclosure, which follow the general principles of the present disclosure and include common general knowledge or conventional technical means in the technical field not disclosed by the present disclosure. The specification and embodiments are only to be considered as exemplary, and the true scope and spirit of the present disclosure are pointed out by the following claims.

[0058] It should be understood that the present disclosure is not limited to the exact structures described above and shown in the drawings, and various modifications and changes can be made without departing from its scope. The scope of the present disclosure is only limited by the appended claims.

Claims

1. A cell protection circuit, characterized in that, Comprising: a battery cell having a positive electrode and a negative electrode; a power circuit connected to the positive electrode and the negative electrode of the battery cell respectively, and at least one first switching unit is provided in the power circuit; a detection circuit connected to the positive electrode and the negative electrode of the battery cell respectively, at least one second switching unit is provided in the detection circuit, and a detection chip is connected to the terminals of the detection circuit respectively for connecting to the positive electrode and the negative electrode of the battery cell, and the detection chip is used for detecting the voltage of the detection circuit; a control mechanism including at least one control chip connected to the power circuit, for controlling the on / off of each of the first switching units and each of the second switching units according to at least one of the voltage and current of the power circuit and the voltage measured by the detection chip.

2. The cell protection circuit according to claim 1, wherein At least one first protection resistor is provided on the line in the detection circuit connected to the positive electrode of the battery cell, and at least one second protection resistor is provided on the line in the detection circuit connected to the negative electrode of the battery cell.

3. The cell protection circuit according to claim 1, characterized in that, Each control chip is connected to one of the first switching units and / or one of the second switching units, for controlling the on / off of the corresponding switching unit according to at least one of the voltage and current of the power circuit.

4. The cell protection circuit according to claim 3, characterized in that, Two first switching units are provided on the line in the power circuit connected to the negative electrode of the battery cell, and one second switching unit is provided on the line in the detection circuit connected to the negative electrode of the battery cell, and the control mechanism includes a first control chip and a second control chip; wherein, the first control chip is used for controlling the on / off of one first switching unit and the second switching unit, and the second control chip is used for controlling the on / off of the other first switching unit.

5. The cell protection circuit according to claim 4, characterized in that, The second control chip includes a first detection terminal, a second detection terminal, a third detection terminal, a fourth detection terminal, a first control terminal and a second control terminal, a first resistor and a first capacitor are connected between the positive electrode and the negative electrode of the battery cell, and a second resistor, a third resistor and two first switching units are sequentially provided on the detection circuit along the direction away from the negative electrode; wherein, the first detection terminal is connected to the line between the first resistor and the first capacitor, the second detection terminal is connected to the negative electrode of the battery cell, the third detection terminal is connected to the line between the two first switching units through a fourth resistor, the fourth detection terminal is connected to the line between the second resistor and the third resistor, and the first control terminal and the second control terminal are respectively connected to the corresponding first switching unit; The first detection terminal, the second detection terminal and the fourth detection terminal are used for detecting the voltage of the power circuit, and the third detection terminal is used for detecting the current of the power circuit.

6. The cell protection circuit according to claim 5, characterized in that, The first switching unit includes two switching tubes, wherein, the first control terminal is connected to one switching tube, the second control terminal is connected to the other switching tube, and the first control terminal and the second control terminal are respectively used for controlling the on / off of the corresponding switching tube.

7. The cell protection circuit according to claim 5, characterized in that, The first control chip includes a fifth detection terminal, a sixth detection terminal, a seventh detection terminal, an eighth detection terminal, a third control terminal and a fourth control terminal, and the positive electrode of the battery cell is grounded through a fifth resistor and a second capacitor; Among them, the fifth detection terminal is connected to the circuit between the fifth resistor and the second capacitor, the sixth detection terminal is grounded, the seventh detection terminal is connected to the circuit on the side of the two first switch units away from the negative electrode of the battery cell through a sixth resistor, and the eighth detection terminal is connected to the circuit between the third resistor and the first switch unit; The fifth detection terminal, the sixth detection terminal and the eighth detection terminal are used to detect the voltage of the power loop, and the seventh detection terminal is used to detect the current of the power loop.

8. The cell protection circuit according to claim 7, wherein The first switch unit includes two switching tubes. Among them, the third control terminal is connected to one switching tube, the fourth control terminal is connected to the other switching tube, and the third control terminal and the fourth control terminal are respectively used to control the on-off of the corresponding switching tubes.

9. The cell protection circuit according to claim 7, characterized in that, At least one of the third control terminal and the fourth control terminal is connected to the second switch unit to control the on-off of the second switch unit.

10. A battery, characterized in that, It includes the battery cell protection circuit according to any one of claims 1 to 9.

11. A terminal device, characterized in that, It includes the battery according to claim 10.

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