Cell protection circuit and rechargeable battery

Abstract

The present invention discloses a battery cell protection circuit and a rechargeable battery. The battery cell protection circuit includes a voltage monitoring circuit, a power management circuit, a communication interface, an oscillator, a drive control circuit, a control switch, and a dissipating resistor. The monitoring terminal of the voltage monitoring circuit is connected to the first connection terminal of the control switch, and the connection point serves as the positive connection terminal of the battery cell protection circuit. The output terminal of the voltage monitoring circuit is connected to the first input terminal of the drive control circuit. Two connection terminals of the power management circuit are respectively connected to the ground terminal and the reference voltage terminal. The regulated output terminal of the power management circuit is connected to the voltage input terminal of the voltage monitoring circuit and the voltage input terminal of the communication interface. For the above battery cell protection circuit, the battery cell voltage is monitored through the voltage monitoring circuit, and at the same time, the sensing signal of the sensor is obtained through the communication interface. Based on the battery cell voltage and the sensing signal, the control circuit is triggered to be short-circuited to achieve all-round protection, and monitoring is carried out from multiple aspects to improve the reliability of battery cell protection.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy, and particularly to a cell protection circuit and a rechargeable battery. Background Art

[0002] With the rapid development of the new energy industry, new energy vehicles have been widely used. The new energy vehicles are equipped with batteries for energy storage and energy supply. The batteries are usually formed by combining cells. During the operation of the cells, the electrochemical characteristics may change due to short circuit, overheating, etc., further causing harmful results such as fire and combustion. In the existing technical methods, temperature monitoring is usually carried out to perform open circuit protection on the cells when overheating occurs. However, in the case of only monitoring the temperature in the existing technology, it is difficult to cope with various emergencies caused by the change of physical and chemical properties of the cells, which affects the reliability of monitoring and protecting the cells. Therefore, the technical methods for monitoring and protecting cells in the existing technology have the problem of low reliability. Summary of the Invention

[0003] An embodiment of the present invention provides a cell protection circuit, aiming to solve the problem of low reliability existing in the technical methods for monitoring and protecting cells in the existing technology.

[0004] In a first aspect, an embodiment of the present invention provides a cell protection circuit, which includes a voltage monitoring circuit, a power management circuit, a communication interface, an oscillator, a drive control circuit, a control switch, and a dissipating resistor.

[0005] The monitoring terminal of the voltage monitoring circuit is connected to the first connection end of the control switch, and the connection point serves as the positive connection end of the cell protection circuit; the output terminal of the voltage monitoring circuit is connected to the first input terminal of the drive control circuit.

[0006] Two connection ends of the power management circuit are respectively connected to the ground terminal and the reference voltage terminal; the regulated output terminal of the power management circuit is connected to the voltage input terminal of the voltage monitoring circuit and the voltage input terminal of the communication interface.

[0007] The signal input terminal of the communication interface is used to input a control signal; the clock signal output terminal of the oscillator is connected to the clock signal input terminal of the communication interface; the control output terminal of the communication interface is connected to the second input terminal of the drive control circuit; the control output terminal of the drive control circuit is connected to the control terminal of the control switch, the second connection end of the control switch is connected to one end of the dissipating resistor, and the other end of the dissipating resistor serves as the negative connection end of the cell protection circuit.

[0008] In a second aspect, an embodiment of the present application further provides a rechargeable battery, wherein the rechargeable battery includes a sensor, a protection board, a cell protection circuit as described in the first aspect above, and at least one group of cells, and the cells are connected in series and / or in parallel;

[0009] The positive electrode post of the cell is connected to the positive connection end of the cell protection circuit and the positive electrode access end of the protection board; the negative electrode post of the cell is connected to the negative connection end of the cell protection circuit and the negative electrode access end of the protection board;

[0010] The sensor is disposed on the outer shell of the cell, and the ground pin, reference voltage pin, positive signal pin, and negative signal pin of the sensor are all connected to both the cell protection circuit and the protection board;

[0011] The ground pin is connected to the ground end of the cell protection circuit, the reference voltage pin is connected to the reference voltage end, and the positive signal pin and the negative signal pin are respectively connected to the two signal input ends of the communication interface.

[0012] An embodiment of the present invention provides a cell protection circuit and a rechargeable battery. The cell protection circuit includes a voltage monitoring circuit, a power management circuit, a communication interface, an oscillator, a drive control circuit, a control switch, and a dissipating resistor; the monitoring end of the voltage monitoring circuit is connected to the first connection end of the control switch, and the connection point serves as the positive connection end of the cell protection circuit; the output end of the voltage monitoring circuit is connected to the first input end of the drive control circuit; the two connection ends of the power management circuit are respectively connected to the ground end and the reference voltage end; the regulated output end of the power management circuit is connected to the voltage input end of the voltage monitoring circuit and the voltage input end of the communication interface. For the above cell protection circuit, the voltage monitoring circuit monitors the cell voltage, and at the same time, the communication interface obtains the sensing signal of the sensor, and based on the cell voltage and the sensing signal, the control circuit is triggered to short-circuit to achieve all-round protection, so that the change state of the cell can be monitored from multiple aspects and the reliability of cell protection can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0014] Figure 1 It is the overall circuit structure diagram of the cell protection circuit provided by the embodiment of the present invention;

[0015] Figure 2Schematic diagram of the application process of the battery cell protection circuit provided by the embodiment of the present invention;

[0016] Figure 3 Circuit structure diagram of the drive control circuit in the battery cell protection circuit provided by the embodiment of the present invention;

[0017] Figure 4 Schematic diagram of the structure of the power management circuit in the battery cell protection circuit provided by the embodiment of the present invention;

[0018] Figure 5 Circuit structure diagram of the voltage monitoring circuit in the battery cell protection circuit provided by the embodiment of the present invention;

[0019] Figure 6 Circuit structure diagram of the oscillator in the battery cell protection circuit provided by the embodiment of the present invention;

[0020] Figure 7 Circuit structure diagram of the rechargeable battery provided by the embodiment of the present invention.

[0021] Reference numerals: 30, battery cell protection circuit; 301, voltage monitoring circuit; 302, power management circuit; 303, communication interface; 304, oscillator; 305, drive control circuit; 306, control switch; 307, dissipative resistor; 202, signal processing and control module; D1, diode; C1, first capacitor; NAND1, first NAND gate; NAND2, second NAND gate; NOR1, first NOR gate; 203, first inverter chain; 204, second inverter chain; S1, first inverter; S2, second inverter; M1, first MOS transistor; M2, second MOS transistor; R2, second resistor; R3, third resistor; R4, fourth resistor; R5, fifth resistor; R6, sixth resistor; R7, seventh resistor; C2, second capacitor; C3, third capacitor; M3, third MOS transistor; M4, fourth MOS transistor; CMP1, first comparator; S3, third inverter; S4, fourth inverter; AMP1, first operational amplifier; 205, bandgap reference regulator; CMP2, second comparator; R8, eighth resistor; RP, potentiometer; BUF, buffer; R9, ninth resistor; R10, tenth resistor; R11, eleventh resistor; C4, fourth capacitor; C5, fifth capacitor; C6, sixth capacitor; C7, seventh capacitor; AMP2, second operational amplifier; CMP3, third comparator; CMP4, fourth comparator; M5, fifth MOS transistor; M6, sixth MOS transistor; M7, seventh MOS transistor; M8, eighth MOS transistor; M9, ninth MOS transistor; M10, tenth MOS transistor; M11, eleventh MOS transistor; NAND3, third NAND gate; NAND4, fourth NAND gate; S5, fifth inverter; S6, sixth inverter; S7, seventh inverter; 10, battery cell; 101, positive terminal; 102, negative terminal; 40, protection board; 50, sensor; 60, explosion-proof valve. Detailed implementation manners

[0022] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0023] It should be understood that when used in this specification and the appended claims, the terms "comprises" and "comprising" indicate the presence of the described features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or their groups.

[0024] It should also be understood that the terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the specification of the present invention and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include the plural forms.

[0025] It should be further understood that the term "and / or" used in the specification of the present invention and the appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0026] Please refer to Figures 1 to 2 , as shown in the figure, an embodiment of the present application discloses a battery cell protection circuit 30. Among them, the battery cell protection circuit 30 includes a voltage monitoring circuit 301, a power management circuit 302, a communication interface 303, an oscillator 304, a drive control circuit 305, a control switch 306 and a dissipating resistor 307; the monitoring end of the voltage monitoring circuit 301 is connected to the first connection end of the control switch 306, and the connection point serves as the positive connection end of the battery cell protection circuit 30; the output end of the voltage monitoring circuit 301 is connected to the first input end of the drive control circuit 305; the two connection ends of the power management circuit 302 are respectively connected to the ground end and the reference voltage end; the regulated output end of the power management circuit 302 is connected to the voltage input end of the voltage monitoring circuit 301 and the voltage input end of the communication interface 303; the signal input end of the communication interface 303 is used to input a control signal; the clock signal output end of the oscillator 304 is connected to the clock signal input end of the communication interface; the control output end of the communication interface 303 is connected to the second input end of the drive control circuit 305; the control output end of the drive control circuit 305 is connected to the control end of the control switch 306, the second connection end of the control switch 306 is connected to one end of the dissipating resistor 307, and the other end of the dissipating resistor 307 serves as the negative connection end of the battery cell protection circuit 30.

[0027] Among them, the oscillator 304 is used to provide a logic clock signal CLK for the communication interface 303, and the communication interface 303 can be an I2C communication interface 303. The voltage monitoring circuit 301 is used to monitor the voltage of the battery cell 10 and provide undervoltage protection for the battery cell protection circuit 30. When the voltage monitoring circuit 301 detects that the voltage of the battery cell 10 is undervoltage, the voltage monitoring circuit 301 sends an undervoltage protection signal to the drive control circuit 305; the drive control circuit 305 can also receive a short-circuit protection signal through the communication interface 303. If the drive control circuit 305 receives an undervoltage protection signal or a short-circuit protection signal, it issues a command signal to control the conduction of the control switch 306, thereby short-circuiting the positive and negative electrodes of the battery cell 10 for protection. At this time, a current flows between the positive and negative electrodes of the battery cell 10 and dissipates through the dissipation resistor 307, and the electrical energy inside the battery cell 10 is released, thereby realizing the protection of the battery cell 10. The reference voltage terminal is used to output a reference voltage VCC. As Figure 1 shown, the undervoltage protection signal can be the OUT signal, the short-circuit protection signal output by the communication interface 303 can be the G1 signal, and the on-off control signal issued by the drive control circuit 305 is the VG signal.

[0028] In a more specific embodiment, the control switch 306 is a MOS switch tube. Specifically, a diode D1 is serially arranged between the first connection end and the second connection end of the MOS switch tube, and the positive electrode of the diode D1 is connected to the second connection end of the MOS switch tube.

[0029] Specifically, to improve the short-circuit control effect, the control switch 306 can be set as a MOS switch tube; to further enhance the control effect of the MOS switch tube, a diode D1 can be serially arranged between the first connection end and the second connection end of the MOS switch tube, and the positive electrode of the diode D1 is connected to the second connection end of the MOS switch tube. When the MOS switch tube is set as an NMOS tube, the positive electrode of the diode D1 can be connected to the source electrode of the NMOS tube.

[0030] In a more specific embodiment, the cell protection circuit 30 further includes a first capacitor C1, and the first capacitor C1 is connected in parallel between two connection terminals of the power management circuit 302. Among them, the power management circuit 302 includes a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, a second capacitor C2, a third capacitor C3, a third MOS transistor M3, a fourth MOS transistor M4, a first comparator CMP1, a third inverter S3, a fourth inverter S4, a first operational amplifier AMP1, and a bandgap reference regulator 205; one end of the second resistor R2 is connected to one end of the bandgap reference regulator 205 and the source electrode of the third MOS transistor M3, and the connection point serves as a connection terminal of the power management circuit 302 to connect to the reference voltage terminal; the other end of the second resistor R2 is connected to one end of the third resistor R3 and the positive input terminal of the first comparator CMP1; the other end of the third resistor R3 is connected to one end of the fourth resistor R4 and the drain electrode of the fourth MOS transistor M4; the other end of the fourth resistor R4 is connected to the source electrode of the fourth MOS transistor M4, and the connection point serves as the other ground of the power management circuit 302; the other end of the bandgap reference regulator 205 is connected to the negative input terminal of the first comparator CMP1 and the negative input terminal of the first operational amplifier AMP1, and the connection point serves as the bandgap reference voltage output terminal; the output terminal of the first comparator CMP1 is connected to the input terminal of the third inverter S3, the output terminal of the third inverter S3 is connected to the gate electrode of the fourth MOS transistor M4 and the input terminal of the fourth inverter S4, and the output terminal of the fourth inverter S4 serves as the comparison voltage output terminal of the power management circuit 302; the output terminal of the first operational amplifier AMP1 is connected to one end of the fifth resistor R5 and the gate electrode of the third MOS transistor M3, the other end of the fifth resistor R5 is connected to one end of the second capacitor C2, the drain electrode of the third MOS transistor M3 is connected to the other end of the second capacitor C2, one end of the sixth resistor R6, and one end of the third capacitor C3, and the connection point serves as the regulated output terminal of the power management circuit 302; the positive input terminal of the first operational amplifier AMP1 is connected to the other end of the sixth resistor R6 and one end of the seventh resistor R7, and the other end of the seventh resistor R7 is connected to the other end of the third capacitor C3 and grounded.

[0031] Further, to increase the isolation degree between the two connection terminals of the power management circuit 302, a first capacitor C1 can be connected in parallel between the two connection terminals, and the specific setting structure is as Figure 1 shown. The specific circuit structure of the power management circuit 302 is as Figure 5As shown, the comparison voltage output terminal of the power management circuit 302 is used to output the comparison voltage POK, the bandgap reference voltage output terminal is used to output the bandgap reference voltage VBG, and the regulated output terminal of the power management circuit 302 is used to output the voltage VLDO.

[0032] In a more specific embodiment, as Figure 3 As shown, the drive control circuit 305 includes a first NAND gate NAND1, a second NAND gate NAND2, a first NOR gate NOR1, a first inverter chain S1 chain 203, a second inverter chain S2 chain 204, a first inverter S1, a second inverter S2, a first MOS transistor M1, and a second MOS transistor M2; two input terminals of the first NAND gate NAND1 are respectively used as the first input terminal and the second input terminal of the drive control circuit 305; an output terminal of the first NAND gate NAND1 is connected to a first input terminal of the second NAND gate NAND2 and a second input terminal of the first NOR gate NOR1; a second input terminal of the second NAND gate NAND2 is connected to an output terminal of the first inverter S1; a first input terminal of the first NOR gate NOR1 is connected to an output terminal of the second inverter S2; an output terminal of the second NOR gate is connected to an input terminal of the first inverter chain S1 chain 203, and an output terminal of the first inverter chain S1 chain 203 is connected to an input terminal of the second inverter S2 and a gate of the first MOS transistor M1; an output terminal of the first NOR gate NOR1 is connected to an input terminal of the second inverter chain S2 chain 204, and an output terminal of the second inverter chain S2 chain 204 is connected to an input terminal of the first inverter S1 and a gate of the second MOS transistor M2; a source of the first MOS transistor M1 is connected to a reference voltage terminal; a drain of the first MOS transistor M1 is connected to a drain of the second MOS transistor M2, and a connection point serves as a control output terminal of the drive control circuit 305; a source of the second MOS transistor M2 is grounded.

[0033] In a more specific embodiment, as Figure 6As shown, the voltage monitoring circuit 301 includes a second comparator CMP2, an eighth resistor R8, a potentiometer RP, and a buffer BUF; the positive input terminal of the buffer BUF serves as the voltage input terminal of the voltage monitoring circuit 301; the negative input terminal of the buffer BUF is connected to the output terminal of the buffer BUF and the positive input terminal of the second comparator CMP2; the negative input terminal of the second comparator CMP2 is connected to one end of the eighth resistor R8 and one end of the potentiometer RP; the other end of the eighth resistor R8 is grounded, and the other end of the potentiometer RP is used to externally connect to the positive electrode of the battery cell 10; the comparison voltage input terminal of the second comparator CMP2 is connected to the comparison voltage output terminal of the power management circuit 302; the output terminal of the second comparator CMP2 serves as the output terminal of the voltage monitoring circuit 301. Among them, VREF is the reference voltage.

[0034] Specifically, as Figure 4As shown, the oscillator 304 includes a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11, a fourth capacitor C4, a fifth capacitor C5, a sixth capacitor C6, a seventh capacitor C7, a second operational amplifier AMP2, a third comparator CMP3, a fourth comparator CMP4, a fifth MOS transistor M5, a sixth MOS transistor M6, a seventh MOS transistor M7, an eighth MOS transistor M8, a ninth MOS transistor M9, a tenth MOS transistor M10, an eleventh MOS transistor M11, a third NAND gate NAND3, a fourth NAND gate NAND4, a fifth inverter S5, a sixth inverter S6, and a seventh inverter S7; one end of the eleventh resistor R11 is connected to the bandgap reference voltage output terminal, the other end of the eleventh resistor R11 is connected to one end of the fourth capacitor C4 and the negative input terminal of the second operational amplifier AMP2, the other end of the fourth capacitor C4 is grounded, the positive input terminal of the second operational amplifier AMP2 is connected to one end of the ninth resistor R9 and one end of the tenth resistor R10, the output terminal of the second operational amplifier AMP2 is connected to one end of the fifth capacitor C5 and the gate of the sixth MOS transistor M6, the other end of the fifth capacitor C5 and the other end of the tenth resistor R10 are both grounded; the source of the sixth MOS transistor M6 is connected to the other end of the ninth resistor R9, and the connection point serves as the clock signal synchronization terminal; the source of the sixth MOS transistor M6 is connected to the gate of the seventh MOS transistor M7, the drain and gate of the fifth MOS transistor M5, and the source of the fifth MOS transistor M5 is connected to the source of the seventh MOS transistor M7 and the reference voltage terminal; the drain of the seventh MOS transistor M7 is connected to the source of the eighth MOS transistor M8 and the source of the tenth MOS transistor M10; the gate of the eighth MOS transistor M8 is connected to the gate of the ninth MOS transistor M9, the output terminal of the fifth inverter S5, and the input terminal of the sixth inverter S6; the drain of the eighth MOS transistor M8 is connected to the drain of the ninth MOS transistor M9, one end of the sixth capacitor C6, and the negative input terminal of the third comparator CMP3; the source of the ninth MOS transistor M9 is connected to the other end of the sixth capacitor C6, the source of the eleventh MOS transistor M11, and one end of the seventh capacitor C7; the drain of the tenth MOS transistor M10 is connected to the drain of the eleventh MOS transistor M11, the other end of the seventh capacitor C7, and the negative input terminal of the fourth comparator CMP4; the positive input terminal of the fourth comparator CMP4 is connected to the positive input terminal of the third comparator CMP3 and the clock signal synchronization terminal; the gate of the tenth MOS transistor M10 is connected to the gate of the eleventh MOS transistor M11, the second input terminal of the third NAND gate NAND3, the output terminal of the fourth NAND gate NAND4, and the input terminal of the fifth inverter S5; the output terminal of the third comparator CMP3 is connected to the first input terminal of the third NAND gate NAND3;The output terminal of the fourth comparator CMP4 is connected to the second input terminal of the fourth NAND gate NAND4, and the output terminal of the third NAND gate NAND3 is connected to the first input terminal of the fourth NAND gate NAND4; the output terminal of the sixth inverter S6 is connected to the input terminal of the seventh inverter S7, and the output terminal of the seventh inverter S7 serves as the clock signal output terminal of the oscillator 304.;

[0035] Among them, the clock signal synchronization terminal is used to output a clock synchronization signal VR_CLK for clock signal synchronization.

[0036] The embodiment of the present application also discloses a rechargeable battery, as Figure 7 shown, the rechargeable battery includes a sensor 50, a protection board 40, the cell protection circuit 30 described in the above embodiment, and at least one group of cells 10, and the cells 10 are connected in series and / or in parallel; the positive electrode post 101 of the cell 10 is connected to the positive connection end of the cell protection circuit 30 and the positive electrode access end of the protection board 40; the negative electrode post 102 of the cell 10 is connected to the negative connection end of the cell protection circuit 30 and the negative electrode access end of the protection board 40; the sensor 50 is disposed on the outer shell of the cell 10, and the ground pin, reference voltage pin, positive signal pin, and negative signal pin of the sensor 50 are all connected to the cell protection circuit 30 and the protection board 40 at the same time; the ground pin is connected to the ground end of the cell protection circuit 30, the reference voltage pin is connected to the reference voltage end, and the positive signal pin and the negative signal pin are respectively connected to the two signal input ends of the communication interface 303.

[0037] When the cells 10 are connected in series, that is, the negative electrode post 102 of the previous group of cells 10 is connected to the positive electrode of the next group of cells 10 to achieve series output; when the cells 10 are connected in parallel, that is, the positive electrode posts 101 of all the cells 10 are connected to each other, and the negative electrode posts 102 of all the cells 10 are also connected. The positive signal pin and the negative signal pin of the sensor 50 are used to output an induction signal to the protection board 40, and the protection board 40 analyzes the induction signal and determines whether the induction signal is abnormal. If the induction signal is abnormal, a short-circuit protection signal is output to the cell protection circuit 30. The sensor 50 is used to sense and monitor the physical and chemical properties inside the cell 10 and output an induction signal in real time. The sensor 50 can be a pressure sensor 50 or a temperature sensor 50, or a sensor 50 obtained by integrating a pressure sensor 50 and a temperature sensor 50. If the sensor 50 is a pressure sensor 50, the obtained induction signal is also a pressure induction signal.

[0038] Specifically, the rechargeable battery further includes an explosion-proof valve 60, and the explosion-proof valve 60 is disposed on the outer shell of the battery cell 10. The explosion-proof valve 60 can increase the safety during the use of the battery cell 10. When the internal pressure of the battery cell 10 exceeds the pressure threshold set by the explosion-proof valve 60, the explosion-proof valve 60 is broken by the pressure and releases the internal pressure of the battery cell 10, avoiding the explosion of the battery cell 10 due to excessive internal pressure during use, thereby increasing the reliability of the protection of the battery cell 10.

[0039] In the battery cell protection circuit 30 and the rechargeable battery provided by the embodiments of the present invention, the battery cell protection circuit 30 includes a voltage monitoring circuit 301, a power management circuit 302, a communication interface 303, an oscillator 304, a drive control circuit 305, a control switch 306, and a dissipation resistor 307; the monitoring end of the voltage monitoring circuit 301 is connected to the first connection end of the control switch 306, and the connection point serves as the positive connection end of the battery cell protection circuit 30; the output end of the voltage monitoring circuit 301 is connected to the first input end of the drive control circuit 305; two connection ends of the power management circuit 302 are respectively connected to the ground end and the reference voltage end; the regulated output end of the power management circuit 302 is connected to the voltage input end of the voltage monitoring circuit 301 and the voltage input end of the communication interface 303. The above-mentioned battery cell protection circuit 30 monitors the voltage of the battery cell 10 through the voltage monitoring circuit 301, and at the same time obtains the sensing signal of the sensor 50 through the communication interface 303, and triggers the short circuit of the control circuit based on the voltage of the battery cell 10 and the sensing signal to achieve all-round protection, so as to be able to monitor the change state of the battery cell 10 from multiple aspects and improve the reliability of the protection of the battery cell 10.

[0040] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of various equivalent modifications or substitutions, and these modifications or substitutions should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A battery cell protection circuit, characterized in that: Including voltage monitoring circuit, power management circuit, communication interface, oscillator, drive control circuit, control switch and dissipation resistor; The monitoring end of the voltage monitoring circuit is connected to the first connection end of the control switch, and the connection point serves as the positive connection end of the battery cell protection circuit; the output end of the voltage monitoring circuit is connected to the first input end of the drive control circuit; The two connection terminals of the power management circuit are connected to the ground terminal and the reference voltage terminal respectively; the voltage stabilization output terminal of the power management circuit is connected to the voltage input terminal of the voltage monitoring circuit and the voltage input terminal of the communication interface; The signal input end of the communication interface is used to input a control signal; the clock signal output end of the oscillator is connected to the clock signal input end of the communication interface; the control output end of the communication interface is connected to the second input end of the drive control circuit; the control output end of the drive control circuit is connected to the control end of the control switch, the second connection end of the control switch is connected to one end of the dissipation resistor, and the other end of the dissipation resistor serves as the negative connection end of the battery protection circuit; The power management circuit includes a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, a second capacitor, a third capacitor, a third MOS transistor, a fourth MOS transistor, a first comparator, a third inverter, a fourth inverter, a first operational amplifier and a bandgap reference regulator; One end of the second resistor is connected to one end of the bandgap reference regulator and the source of the third MOS tube, and the connection point is connected to the reference voltage terminal as a connection end of the power management circuit; The other end of the second resistor is connected to one end of the third resistor and the positive input end of the first comparator; the other end of the third resistor is connected to one end of the fourth resistor and the drain of the fourth MOS tube; the other end of the fourth resistor is connected to the source of the fourth MOS tube, and the connection point serves as another grounding of the power management circuit; The other end of the bandgap reference regulator is connected to the negative input end of the first comparator and the negative input end of the first operational amplifier, and the connection point serves as the bandgap reference voltage output end; the output end of the first comparator is connected to the input end of the third inverter, the output end of the third inverter is connected to the gate of the fourth MOS tube and the input end of the fourth inverter, and the output end of the fourth inverter serves as the comparison voltage output end of the power management circuit; The output end of the first operational amplifier is connected to one end of the fifth resistor and the gate of the third MOS transistor, the other end of the fifth resistor is connected to one end of the second capacitor, the drain of the third MOS transistor is connected to the other end of the second capacitor, one end of the sixth resistor, and one end of the third capacitor, and the connection point serves as the voltage-stabilizing output end of the power management circuit; The positive input terminal of the first operational amplifier is connected to the other end of the sixth resistor and one end of the seventh resistor, and the other end of the seventh resistor is connected to the other end of the third capacitor and is grounded.

2. The battery cell protection circuit according to claim 1, characterized in that: The control switch is a MOS switch tube.

3. The battery cell protection circuit according to claim 2, characterized in that: A diode is arranged in series between the first connection end and the second connection end of the MOS switch tube, and the anode of the diode is connected to the second connection end of the MOS switch tube.

4. The battery cell protection circuit according to any one of claims 1 to 3, characterized in that: The battery cell protection circuit also includes a first capacitor, which is arranged in parallel between two connection ends of the power management circuit.

5. The battery cell protection circuit according to claim 4, characterized in that: The driving control circuit includes a first NAND gate, a second NAND gate, a first NOR gate, a first inverter chain, a second inverter chain, a first inverter, a second inverter, a first MOS transistor and a second MOS transistor; The two input ends of the first NAND gate serve as the first input end and the second input end of the drive control circuit respectively; the output end of the first NAND gate is connected to the first input end of the second NAND gate and the second input end of the first NOR gate; the second input end of the second NAND gate is connected to the output end of the first inverter; the first input end of the first NOR gate is connected to the output end of the second inverter; the output end of the second NAND gate is connected to the input end of the first inverter chain, and the output end of the first inverter chain is connected to the input end of the second inverter and the gate of the first MOS tube; The output end of the first NOR gate is connected to the input end of the second inverter chain, and the output end of the second inverter chain is connected to the input end of the first inverter and the gate of the second MOS tube; the source of the first MOS tube is connected to the reference voltage end; the drain of the first MOS tube is connected to the drain of the second MOS tube, and the connection point serves as the control output end of the drive control circuit; the source of the second MOS tube is grounded.

6. The battery cell protection circuit according to claim 1, characterized in that: The voltage monitoring circuit includes a second comparator, an eighth resistor, a potentiometer and a buffer; The positive input terminal of the buffer serves as the voltage input terminal of the voltage monitoring circuit; the negative input terminal of the buffer is connected to the output terminal of the buffer and the positive input terminal of the second comparator; The negative input terminal of the second comparator is connected to one end of the eighth resistor and one end of the potentiometer; the other end of the eighth resistor is grounded, and the other end of the potentiometer is used for the positive pole of the external battery cell; the comparison voltage input terminal of the second comparator is connected to the comparison voltage output terminal of the power management circuit; the output terminal of the second comparator serves as the output terminal of the voltage monitoring circuit.

7. The battery cell protection circuit according to claim 1, characterized in that: The oscillator includes a ninth resistor, a tenth resistor, an eleventh resistor, a fourth capacitor, a fifth capacitor, a sixth capacitor, a seventh capacitor, a second operational amplifier, a third comparator, a fourth comparator, a fifth MOS transistor, a sixth MOS transistor, a seventh MOS transistor, an eighth MOS transistor, a ninth MOS transistor, a tenth MOS transistor, an eleventh MOS transistor, a third NAND gate, a fourth NAND gate, a fifth inverter, a sixth inverter and a seventh inverter; One end of the eleventh resistor is connected to the bandgap reference voltage output end, the other end of the eleventh resistor is connected to one end of the fourth capacitor and the negative input end of the second operational amplifier, the other end of the fourth capacitor is grounded, the positive input end of the second operational amplifier is connected to one end of the ninth resistor and one end of the tenth resistor, the output end of the second operational amplifier is connected to one end of the fifth capacitor and the gate of the sixth MOS tube, and the other end of the fifth capacitor and the other end of the tenth resistor are both grounded; The source of the sixth MOS tube is connected to the other end of the ninth resistor, and the connection point serves as a clock signal synchronization end; The source of the sixth MOS tube is connected to the gate of the seventh MOS tube, the drain and the gate of the fifth MOS tube, the source of the fifth MOS tube is connected to the source of the seventh MOS tube and the reference voltage terminal; the drain of the seventh MOS tube is connected to the source of the eighth MOS tube and the source of the tenth MOS tube; The gate of the eighth MOS tube is connected to the gate of the ninth MOS tube, the output end of the fifth inverter and the input end of the sixth inverter; the drain of the eighth MOS tube is connected to the drain of the ninth MOS tube, one end of the sixth capacitor and the negative input end of the third comparator; the source of the ninth MOS tube is connected to the other end of the sixth capacitor, the source of the eleventh MOS tube and one end of the seventh capacitor; the drain of the tenth MOS tube is connected to the drain of the eleventh MOS tube, the other end of the seventh capacitor and the negative input end of the fourth comparator; the positive input end of the fourth comparator is connected to the positive input end of the third comparator and the clock signal synchronization end; The gate of the tenth MOS transistor is connected to the gate of the eleventh MOS transistor, the second input end of the third NAND gate, the output end of the fourth NAND gate and the input end of the fifth inverter; the output end of the third comparator is connected to the first input end of the third NAND gate; the output end of the fourth comparator is connected to the second input end of the fourth NAND gate, and the output end of the third NAND gate is connected to the first input end of the fourth NAND gate; the output end of the sixth inverter is connected to the input end of the seventh inverter, and the output end of the seventh inverter serves as the clock signal output end of the oscillator.

8. A rechargeable battery, characterized in that: The rechargeable battery comprises a sensor, a protection board, a cell protection circuit as claimed in any one of claims 1 to 7, and at least one group of cells, wherein the cells are connected in series and / or in parallel; The positive pole of the battery cell is connected to the positive connection end of the battery cell protection circuit and the positive access end of the protection board; the negative pole of the battery cell is connected to the negative connection end of the battery cell protection circuit and the negative access end of the protection board; The sensor is arranged on the housing of the battery cell, and the ground pin, the reference voltage pin, the positive signal pin and the negative signal pin of the sensor are all connected to the battery cell protection circuit and the protection board at the same time; The ground pin is connected to the ground terminal of the battery protection circuit, the reference voltage pin is connected to the reference voltage terminal, and the positive signal pin and the negative signal pin are respectively connected to two signal input terminals of the communication interface.

9. The rechargeable battery according to claim 8, characterized in that: The rechargeable battery further comprises an explosion-proof valve, which is arranged on the outer shell of the battery cell.

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