An overvoltage threshold adjusting circuit, a battery protection chip and a battery

Abstract

The application relates to the technical field of battery protection, and discloses an overvoltage threshold adjusting circuit, a battery protection chip and a battery. The overvoltage threshold adjusting circuit comprises a threshold adjusting module, an overvoltage protection module and a resistance series network. The two ends of the resistance series network are respectively connected with positive poles of the battery, different resistance series nodes of the resistance series network are respectively connected with the threshold adjusting module and the overvoltage protection module, and the threshold adjusting module is connected with a temperature input pin of the battery protection chip. The temperature input pin of the battery protection chip is used for providing a first input voltage corresponding to a current temperature. The threshold adjusting module is used for short-circuiting two resistance series nodes of the resistance series network under the condition that the first input voltage is smaller than a first preset voltage, and adjusting a second input voltage. The overvoltage protection module is used for triggering overvoltage protection of the battery according to a comparison result of the second input voltage and a second preset voltage. The application can adjust the voltage protection threshold according to the change of the temperature, and improves the safety of the battery.

Description

Technical Field

[0001] This application relates to the field of battery protection technology, and in particular to an overvoltage threshold adjustment circuit, a battery protection chip, and a battery. Background Technology

[0002] In existing technologies, once a battery protection chip model is selected, its overvoltage protection threshold is a fixed value and cannot be dynamically adjusted according to the actual operating state of the battery. Although this fixed threshold design is simple in structure and low in cost, it has obvious limitations in practical applications. For example, as the battery's operating environment or operating state changes, the upper limit of the battery's safe voltage may change accordingly, and the fixed overvoltage protection threshold is difficult to adapt to such dynamic changes, which may cause protection failure or malfunction. Utility Model Content

[0003] In view of this, embodiments of this application provide an overvoltage threshold adjustment circuit, a battery protection chip, and a battery, which can effectively solve the problem that the battery overvoltage protection threshold cannot be dynamically adjusted.

[0004] In a first aspect, embodiments of this application provide an overvoltage threshold adjustment circuit, including: a threshold adjustment module, an overvoltage protection module, and a resistor series network;

[0005] The first end of the resistor series network is connected to the positive terminal of the battery, the second end of the resistor series network is grounded, the first and second resistor series nodes of the resistor series network are both connected to the threshold adjustment module, the third resistor series node of the resistor series network is connected to the overvoltage protection module, and the threshold adjustment module is used to connect to the temperature input pin of the battery protection chip.

[0006] The temperature input pin of the battery protection chip is used to provide the threshold adjustment module with a first input voltage corresponding to the current temperature;

[0007] The threshold adjustment module is used to short-circuit the first resistor series node and the second resistor series node of the resistor series network when the first input voltage is less than the first preset voltage, thereby adjusting the second input voltage of the overvoltage protection module.

[0008] The overvoltage protection module is used to trigger the overvoltage protection of the battery based on the comparison result of the second input voltage and the second preset voltage.

[0009] In a first possible embodiment of the first aspect, the threshold adjustment module includes a switching transistor, a first comparator, a first voltage divider resistor, and a second voltage divider resistor;

[0010] The non-inverting input of the first comparator is connected to the temperature input pin of the battery protection chip, and the inverting input of the first comparator is connected to the series connection node of the first voltage divider resistor and the second voltage divider resistor. The first voltage divider resistor is connected to the positive terminal of the first voltage source, and the second voltage divider resistor is connected to the negative terminal of the first voltage source.

[0011] The output of the first comparator is connected to the control terminal of the switching transistor, the input of the switching transistor is connected to the first resistor series node of the resistor series network, and the output of the switching transistor is connected to the second resistor series node of the resistor series network.

[0012] In a second possible embodiment of the first aspect, the resistor series network includes a third voltage divider resistor, a fourth voltage divider resistor, a fifth voltage divider resistor, and a sixth voltage divider resistor connected in series.

[0013] The series connection node of the third voltage divider resistor and the fourth voltage divider resistor is the first resistor series connection node, the series connection node of the fourth voltage divider resistor and the fifth voltage divider resistor is the second resistor series connection node, and the series connection node of the fifth voltage divider resistor and the sixth voltage divider resistor is the third resistor series connection node.

[0014] In a third possible embodiment of the first aspect, the overvoltage protection module includes a second comparator;

[0015] The non-inverting input of the second comparator is connected to the third resistor series node of the resistor series network, and the inverting input of the second comparator is connected to the second voltage source;

[0016] Alternatively, the inverting input of the second comparator is connected to the third resistor series node of the resistor series network, and the non-inverting input of the second comparator is connected to the second voltage source.

[0017] In a fourth possible embodiment of the first aspect, the overvoltage threshold adjustment circuit further includes: a temperature detection module connected to the temperature input pin of the battery protection chip;

[0018] The temperature detection module is used to convert the measured battery temperature into a voltage signal and input it to the temperature input pin of the battery protection chip.

[0019] In a fifth possible embodiment of the first aspect, the temperature detection module includes a thermistor;

[0020] The first end of the thermistor is connected to the negative terminal of the battery and the ground pin of the battery protection chip, respectively, and the second end of the thermistor is connected to the temperature input pin of the battery protection chip.

[0021] Secondly, embodiments of this application provide a battery protection chip, including the overvoltage threshold adjustment circuit described above.

[0022] In a first possible embodiment of the second aspect, the battery protection chip further includes: an over-temperature protection module, the over-temperature protection module being connected to the temperature input pin of the battery protection chip;

[0023] The temperature input pin of the battery protection chip is used to adjust the third input voltage of the over-temperature protection module according to temperature changes;

[0024] The over-temperature protection module is used to trigger the battery's over-temperature protection based on the comparison result between the third input voltage and the third preset voltage.

[0025] In a second possible embodiment of the second aspect, the over-temperature protection module includes a third comparator, a seventh voltage divider resistor, an eighth voltage divider resistor, and a ninth voltage divider resistor;

[0026] The non-inverting input of the third comparator is connected to the temperature input pin of the battery protection chip and the first terminal of the seventh voltage divider resistor, respectively; the second terminal of the seventh voltage divider resistor is connected to the third voltage source.

[0027] The inverting input of the third comparator is connected to the series node of the eighth and ninth voltage divider resistors. The eighth voltage divider resistor is connected to the positive terminal of the fourth voltage source, and the ninth voltage divider resistor is connected to the negative terminal of the fourth voltage source.

[0028] Thirdly, embodiments of this application provide a battery including the aforementioned battery protection chip.

[0029] The embodiments of this application have the following beneficial effects:

[0030] An overvoltage threshold adjustment circuit according to this embodiment includes: a threshold adjustment module, an overvoltage protection module, and a resistor series network. The two ends of the resistor series network are respectively connected to the positive terminal of the battery. Different series nodes of the resistor series network are respectively connected to the threshold adjustment module and the overvoltage protection module. The threshold adjustment module is connected to the temperature input pin of the battery protection chip. The temperature input pin of the battery protection chip is used to provide a first input voltage corresponding to the current temperature. The threshold adjustment module is used to short-circuit the two series nodes of the resistor series network to adjust the second input voltage when the first input voltage is less than a first preset voltage. The overvoltage protection module is used to trigger the battery's overvoltage protection based on the comparison result of the second input voltage and the second preset voltage. This application can adjust the voltage protection threshold according to temperature changes, and is suitable for high-temperature environments. When the battery's safe upper limit voltage specification is lowered, the overvoltage protection threshold of the corresponding battery protection chip is automatically lowered, further improving battery safety. This overvoltage threshold adjustment circuit can set different overvoltage protection thresholds for the same battery protection chip to meet the needs of batteries with different safe upper limit voltage specifications. Attached Figure Description

[0031] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This paper shows a schematic diagram of a first structure of the overvoltage threshold adjustment circuit according to an embodiment of the present application;

[0033] Figure 2 A schematic diagram of a second structure of the overvoltage threshold adjustment circuit according to an embodiment of this application is shown;

[0034] Figure 3 A circuit diagram of an overvoltage threshold adjustment circuit according to an embodiment of this application is shown;

[0035] Figure 4 This paper shows a schematic diagram of the structure of a battery protection chip according to an embodiment of the present application;

[0036] Figure 5 A circuit diagram of a battery protection chip according to an embodiment of this application is shown.

[0037] Explanation of key component symbols:

[0038] 100 - Overvoltage threshold adjustment circuit; 110 - Threshold adjustment module; 120 - Overvoltage protection module; 130 - Resistor series network; 140 - Temperature detection module; 200 - Battery protection chip; 210 - Over-temperature protection module. Detailed Implementation

[0039] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0040] The components of the embodiments of this application described and illustrated in the accompanying drawings can be arranged and designed in a variety of different configurations. Therefore, the following detailed description of the embodiments of this application provided in the drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0041] In the following text, the terms "comprising," "having," and their cognates, which may be used in various embodiments of this application, are intended only to indicate a particular feature, number, step, operation, element, component, or combination thereof, and should not be construed as primarily excluding the presence of one or more other features, numbers, steps, operations, elements, components, or combinations thereof, or adding the possibility of one or more combinations thereof. Furthermore, the terms "first," "second," "third," etc., are used only for distinguishing descriptions and should not be construed as indicating or implying relative importance.

[0042] Unless otherwise specified, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which the various embodiments of this application pertain. Terms (such as those defined in commonly used dictionaries) shall be interpreted as having the same meaning as in their contextual meaning in the relevant technical field and shall not be construed as having an idealized or overly formal meaning, unless clearly defined in the various embodiments of this application.

[0043] The following detailed description of some embodiments of this application is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0044] Battery protection circuits, as a crucial component ensuring safe battery operation, are widely used in battery management systems. Currently, mainstream battery protection solutions typically employ integrated circuits (ICs) to achieve real-time monitoring and protection against anomalies in battery parameters such as voltage, current, and temperature. In existing designs, once a specific IC model is selected, the overvoltage protection threshold is fixed. The IC also features overtemperature protection, typically triggering a protection mechanism when the temperature exceeds 60°C. However, in practical applications, the normal operating temperature range of batteries is usually between 45°C and 60°C. Within this temperature range, although the battery is operating normally, its safe voltage limit may have decreased. Using a fixed overvoltage protection threshold at this point could result in a relatively high protection threshold, failing to respond promptly to abnormal battery conditions and posing a safety hazard.

[0045] Furthermore, to address the various shortcomings of the prior art, this application proposes an overvoltage threshold adjustment circuit, a battery control chip, and a battery. By dynamically adjusting the overvoltage protection threshold, especially automatically lowering the protection threshold under high-temperature conditions, it overcomes the safety hazards caused by fixed thresholds in the prior art. Simultaneously, by using an external resistor setting method, it achieves flexible configuration of the overvoltage protection threshold to meet the needs of batteries with different safety upper voltage limits.

[0046] Please refer to Figure 1 This is a schematic diagram of an overvoltage threshold adjustment circuit 100 provided in an embodiment of this application. Exemplarily, the overvoltage threshold adjustment circuit 100 includes a threshold adjustment module 110, an overvoltage protection module 120, and a resistor series network 130. The first end of the resistor series network 130 is connected to the positive terminal of the battery, the second end of the resistor series network 130 is grounded, the first and second resistor series nodes of the resistor series network 130 are both connected to the threshold adjustment module 110, and the third resistor series node of the resistor series network 130 is connected to the overvoltage protection module 120. The threshold adjustment module 110 is used to connect to the temperature input pin TH of the battery protection chip 200.

[0047] In this embodiment, the temperature input pin TH of the battery protection chip 200 is used to provide a first input voltage corresponding to the current temperature to the threshold adjustment module 110. The threshold adjustment module 110 is used to short-circuit the first and second resistor series nodes of the resistor series network 130 when the first input voltage is less than a first preset voltage, thereby adjusting the second input voltage of the overvoltage protection module 120. The overvoltage protection module 120 is used to trigger overvoltage protection of the battery based on the comparison result of the second input voltage and the second preset voltage. When the first and second resistor series nodes are short-circuited, the connection resistance of the overvoltage protection module 120 changes, thereby increasing the second input voltage of the overvoltage protection module 120 under the condition that the positive voltage of the battery remains unchanged. When the second input voltage is greater than the second preset voltage, overvoltage protection is triggered, and the overvoltage protection threshold is lowered.

[0048] In one embodiment, such as Figure 2 As shown, the overvoltage threshold adjustment circuit 100 further includes a temperature detection module 140, which is connected to the temperature input pin TH of the battery protection chip 200. The temperature detection module 140 converts the measured battery temperature into a voltage signal and inputs it to the temperature input pin TH of the battery protection chip 200. In this embodiment, the battery protection chip 200 measures the voltage across the temperature detection module 140 via the temperature input pin TH and uses this voltage signal as the first input voltage of the threshold adjustment module 110. When the temperature reaches a certain threshold, the first input voltage is less than the second preset voltage of the threshold adjustment module 110. The threshold adjustment module 110 then short-circuits the first resistor series node and the second resistor series node, lowering the overvoltage protection threshold of the overvoltage protection module 120. For example, the temperature input pin TH of the battery protection chip 200 can convert the input voltage signal into a digital signal using an analog-to-digital converter. The battery protection chip 200 can then measure the voltage across the temperature detection module 140 using this digital signal and determine the battery temperature by measuring the voltage.

[0049] In one implementation, such as Figure 3 As shown, the temperature detection module 140 includes a thermistor RT1. The first end of the thermistor RT1 is connected to the negative terminal of the battery and the ground pin of the battery protection chip 200, respectively. The second end of the thermistor RT1 is connected to the temperature input pin TH of the battery protection chip 200. In this embodiment, the temperature input pin TH of the battery protection chip 200 is used to measure the voltage across the thermistor RT1. The higher the battery temperature, the lower the resistance of the thermistor RT1, and the lower the voltage detected by the temperature input pin TH of the battery protection chip 200.

[0050] In one embodiment, the threshold adjustment module 110 includes a switch Q1, a first comparator T1, a first voltage divider resistor R1, and a second voltage divider resistor R2. Exemplarily, the non-inverting input of the first comparator T1 is connected to the temperature input pin TH of the battery protection chip 200, and the inverting input of the first comparator T1 is connected to the series connection node of the first voltage divider resistor R1 and the second voltage divider resistor R2. The first voltage divider resistor R1 is connected to the positive terminal of the first voltage source VCC1, and the second voltage divider resistor R2 is connected to the negative terminal of the first voltage source VCC1. The output of the first comparator T1 is connected to the control terminal of the switch Q1, the input of the switch Q1 is connected to the first resistor series node of the resistor series network 130, and the output of the switch Q1 is connected to the second resistor series node of the resistor series network 130. The switch Q1 includes, but is not limited to, transistors, MOSFETs, etc.

[0051] In one embodiment, the first input voltage is the non-inverting input voltage of the first comparator T1. The first voltage divider resistor R1, the second voltage divider resistor R2, and the first voltage source VCC1 form a resistor divider circuit to drive the inverting input of the first comparator T1. The voltage at the inverting input of the first comparator T1 is the first preset voltage of the threshold adjustment module 110, determined by the resistance ratio of the first voltage divider resistor R1 and the second voltage divider resistor R2. This application allows setting the resistance ratio of the first voltage divider resistor R1 and the second voltage divider resistor R2, or selecting thermistors RT1 of different specifications, to ensure that at a preset temperature, the voltage at the non-inverting input of the first comparator T1 is less than the voltage at the inverting input. The first comparator T1 then provides a level signal to the switching transistor Q1, causing Q1 to conduct. The preset temperature can be set according to the actual situation. For example, the preset temperature can be set to 45℃. By setting the resistance ratio of the first voltage divider resistor R1 and the second voltage divider resistor R2 or selecting the thermistor RT1 of the appropriate specification, the first comparator T1 will trigger the switch Q1 to conduct at 45℃, thereby reducing the overvoltage protection threshold at the preset temperature.

[0052] In one embodiment, the resistor series network 130 includes a third voltage divider resistor R3, a fourth voltage divider resistor R4, a fifth voltage divider resistor R5, and a sixth voltage divider resistor R6 connected in series. Exemplarily, the series connection point of the third voltage divider resistor R3 and the fourth voltage divider resistor R4 is a first resistor series connection point, the series connection point of the fourth voltage divider resistor R4 and the fifth voltage divider resistor R5 is a second resistor series connection point, and the series connection point of the fifth voltage divider resistor R5 and the sixth voltage divider resistor R6 is a third resistor series connection point.

[0053] In this embodiment, the resistor series network 130 provides a second input voltage to the overvoltage protection module 120 that is proportional to the battery charging and discharging voltage. This enables the overvoltage protection module 120 to determine whether the current battery charging and discharging voltage exceeds a set threshold, thereby triggering the overvoltage protection mechanism. Under the condition that the battery positive terminal voltage remains constant, the second input voltage is determined by the resistance ratio of the third voltage divider resistor R3, the fourth voltage divider resistor R4, the fifth voltage divider resistor R5, and the sixth voltage divider resistor R6.

[0054] In one embodiment, when the first comparator T1 drives the switch Q1 to conduct, the switch Q1 short-circuits the fourth voltage divider resistor R4 between the first and second resistor series nodes, thereby changing the resistance ratio. The second input voltage increases while the battery positive terminal voltage remains constant. When the second input voltage exceeds a second preset voltage, the overvoltage protection module 120 triggers the battery's overvoltage protection. This application adjusts the resistance ratio at a preset temperature to adjust the voltage at any input terminal of the overvoltage protection module 120, thereby automatically lowering the overvoltage protection threshold at the preset temperature.

[0055] In one embodiment, since the fourth voltage divider resistor R4 is short-circuited to adjust the voltage at the input terminal of the overvoltage protection module 120, the resistance value of the fourth voltage divider resistor R4 can be set according to the actual situation, controlling the magnitude of the resistance ratio adjustment, and thus setting the amount of reduction in the overvoltage protection threshold. The resistance values ​​of the fourth voltage divider resistor R4 and the fifth voltage divider resistor R5 can be set according to the actual situation, controlling the magnitude of the resistance ratio to set the low-temperature overvoltage protection threshold. For example, when the temperature is less than or equal to 45°C, the resistance values ​​of the fourth voltage divider resistor R4 and the fifth voltage divider resistor R5 can be set so that the low-temperature overvoltage protection threshold is 4.53V. When the temperature is greater than or equal to 45°C, the resistance value of the fourth voltage divider resistor R4 can be set so that the overvoltage protection threshold is reduced to 4.15V.

[0056] In one embodiment, the overvoltage protection module 120 includes a second comparator T2. Exemplarily, the non-inverting input of the second comparator T2 is connected to the third resistor series node of the resistor series network 130, and the inverting input of the second comparator T2 is connected to the second voltage source VCC2. Alternatively, the inverting input of the second comparator T2 is connected to the third resistor series node of the resistor series network 130, and the non-inverting input of the second comparator T2 is connected to the second voltage source VCC2.

[0057] In this embodiment, the second voltage source VCC2 provides a second preset voltage to the second comparator T2. The second input voltage of the overvoltage protection module 120 can be the voltage at the non-inverting input terminal or the voltage at the inverting input terminal of the second comparator T2. This application can adjust the voltage at the non-inverting input terminal or the voltage at the inverting input terminal of the second comparator T2 to automatically lower the overvoltage protection threshold under high temperature conditions. The second comparator T2 is used to determine battery overvoltage based on the comparison result between the second input voltage and the second preset voltage. When the second input voltage is greater than the second preset voltage, it outputs an overvoltage signal to the logic controller in the battery protection chip 200. The logic controller is used to control the battery charging and discharging switch in a timely manner to achieve overvoltage protection for the battery.

[0058] This application also provides a battery protection chip 200, such as Figure 4 As shown, exemplary, the battery protection chip 200 includes the overvoltage threshold adjustment circuit 100 of the above embodiment. Since the battery protection chip 200 employs the above-described overvoltage threshold adjustment circuit 100, it possesses all the advantages of the above-described overvoltage threshold adjustment circuit 100. It is understood that the options in the above embodiments also apply to this embodiment, and therefore will not be described again here.

[0059] In one embodiment, the battery protection chip 200 further includes an over-temperature protection module 210, which is connected to the temperature input pin TH of the battery protection chip 200. The temperature input pin TH of the battery protection chip 200 is used to adjust the third input voltage of the over-temperature protection module 210 according to temperature changes; the over-temperature protection module 210 is used to trigger over-temperature protection of the battery based on a comparison between the third input voltage and a third preset voltage. In this embodiment, the over-temperature protection module 210 compares the first input voltage that changes with temperature with the third preset voltage to determine whether the battery is currently in an over-temperature state, and triggers the corresponding over-temperature protection action accordingly.

[0060] In one implementation, such as Figure 5 As shown, the over-temperature protection module 210 includes a third comparator T3, a seventh voltage divider resistor R7, an eighth voltage divider resistor R8, and a ninth voltage divider resistor R9. Exemplarily, the non-inverting input of the third comparator T3 is connected to the temperature input pin TH of the battery protection chip 200 and the first terminal of the seventh voltage divider resistor R7, respectively; the second terminal of the seventh voltage divider resistor R7 is connected to the third voltage source VCC3. The inverting input of the third comparator T3 is connected to the series connection of the eighth voltage divider resistor R8 and the ninth voltage divider resistor R9; the eighth voltage divider resistor R8 is connected to the positive terminal of the fourth voltage source VCC4, and the ninth voltage divider resistor R9 is connected to the negative terminal of the fourth voltage source VCC4.

[0061] In one embodiment, the third input voltage at the non-inverting input of the third comparator T3 is determined by the voltage of the temperature input pin TH of the battery protection chip 200 and the resistance value of the seventh voltage divider resistor R7. The eighth and ninth voltage divider resistors R8 and R9, along with the fourth voltage source VCC4, form a resistor divider circuit to drive the inverting input of the third comparator T3. The voltage at the inverting input of the third comparator T3 is the third preset voltage of the over-temperature protection module 210, determined by the resistance ratio of the eighth and ninth voltage divider resistors R8 and R9. This application allows setting the resistance ratio of the eighth and ninth voltage divider resistors R8 and R9, or selecting thermistors RT1 of different specifications, to ensure that at a preset temperature, the voltage at the non-inverting input of the third comparator T3 is less than the voltage at the inverting input. The third comparator T3 then provides an over-temperature signal to the logic controller in the battery protection chip 200 to provide over-temperature protection for the battery.

[0062] In this embodiment, the battery protection chip 200 is connected to the battery to provide overvoltage, overtemperature, and overcurrent protection. The battery includes a positive terminal B+, a negative terminal B-, a positive power output terminal P+, and a negative power output terminal P-. The positive terminal B+ represents the battery's positive output terminal and is connected to the positive input terminal of an external load or charger. The positive power output terminal P+ represents the positive output after battery protection control and is used to connect to a load or charger. The negative terminal B- represents the battery's negative output terminal and can be used to connect to the negative input terminal of an external load or charger; it is also the main current loop terminal of the battery protection circuit. The negative power output terminal P- represents the negative output after battery protection control and is used in high-side protection or current detection circuits.

[0063] In one embodiment, the battery protection chip 200 includes a temperature detection pin TH, a ground pin VSS, a positive power supply pin VDD, a current detection pin CS, a discharge control output pin DOUT, a charge control output pin COUT, a voltage measurement pin VM, and a bootstrap pin BS. The positive power supply pin VDD can be connected to the positive terminal of the battery to power the chip, and the ground pin VSS can be connected to the negative terminal of the battery or the system ground plane. The current detection pin CS is connected to one end of a sampling resistor Rsns, and the current flowing through the resistor is measured by measuring the voltage drop across the known sampling resistor Rsns. The discharge control output pin DOUT is used to connect to the discharge switch Q3 to control the on / off state of the discharge path. The charge control output pin COUT is used to connect to the charge switch Q2 to control the on / off state of the charging path. The voltage measurement pin VM is used to monitor the battery voltage. The voltage measurement pin VM is connected to a voltage comparator T4, which detects the charging voltage of the battery to the load and provides a discharge control signal to the logic controller, causing the logic controller to control the discharge switch Q1 to turn on. The BS pin is used to provide a boost voltage for the gate drive circuit of the high-side switch. The logic controller inside the battery protection chip 200 outputs a control signal, which is used to drive the external high-side switch. A current-limiting resistor Rbss is connected in series in the drive path and finally connected to the BS pin of the chip to form a complete bootstrap boost drive circuit.

[0064] In one embodiment, the battery protection chip 200 further includes an undervoltage protection comparator T5. The non-inverting input of the undervoltage protection comparator T5 can be connected to the positive terminal of the battery through a resistor voltage divider circuit. The inverting input of the undervoltage protection comparator T5 is connected to a voltage source, which provides an undervoltage protection threshold for the undervoltage protection comparator. When the voltage at the non-inverting input is less than the voltage at the inverting input, the undervoltage protection comparator T5 provides an undervoltage signal to the logic controller in the battery protection chip 200 to provide undervoltage protection for the battery.

[0065] In one embodiment, the current detection pin CS is connected via a resistor to a charging overcurrent protection comparator T6, a first discharging overcurrent protection comparator T7, a second discharging overcurrent protection comparator T8, and a first short-circuit comparator T9. The voltage measurement pin VM is connected to a second short-circuit comparator T10. The resistor serves as signal isolation and current limiting. The charging overcurrent protection comparator T6 determines whether an overcurrent occurs during charging. The first discharging overcurrent protection comparator T7 and the second discharging overcurrent protection comparator T8 both determine whether an overcurrent occurs during discharging. The first discharging protection comparator T7 and the second discharging overcurrent protection comparator T8 have different overcurrent protection thresholds. The first short-circuit comparator T9 and the second short-circuit comparator T10 determine whether a short circuit has occurred. The first short-circuit comparator T9 and the second short-circuit comparator T10 also have different short-circuit protection thresholds. Each comparator provides an output signal to the logic controller based on its determination result, enabling the logic controller to protect the battery in the event of overcurrent or short circuit.

[0066] In one embodiment, the battery protection chip 200 includes a logic controller for determining whether the battery has triggered battery protection based on the output signals of each comparator. When it is determined that the battery should be protected, the logic controller controls the discharge switch Q3 and the charging switch Q2 through parallel switching transistors.

[0067] This application also provides a battery, exemplary of which includes the battery protection chip 200 of the above embodiment. The battery includes a charging switch Q2 and a discharging switch Q3. The discharging control output pin DOUT of the battery protection chip 200 is connected to the charging switch Q1, and the charging control output pin COUT of the battery protection chip 200 is connected to the discharging switch Q1, controlling the charging and discharging of the battery. The battery includes, but is not limited to, lithium-ion polymer batteries, flash-charge batteries, and pouch batteries.

[0068] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application.

Claims

1. An overvoltage threshold adjustment circuit, characterized in that, Includes: a threshold adjustment module, an overvoltage protection module, and a resistor series network; The first end of the resistor series network is connected to the positive terminal of the battery, the second end of the resistor series network is grounded, the first and second resistor series nodes of the resistor series network are both connected to the threshold adjustment module, the third resistor series node of the resistor series network is connected to the overvoltage protection module, and the threshold adjustment module is used to connect to the temperature input pin of the battery protection chip. The temperature input pin of the battery protection chip is used to provide the threshold adjustment module with a first input voltage corresponding to the current temperature; The threshold adjustment module is used to short-circuit the first resistor series node and the second resistor series node of the resistor series network when the first input voltage is less than the first preset voltage, thereby adjusting the second input voltage of the overvoltage protection module. The overvoltage protection module is used to trigger the overvoltage protection of the battery based on the comparison result of the second input voltage and the second preset voltage.

2. The overvoltage threshold adjustment circuit according to claim 1, characterized in that, The threshold adjustment module includes a switching transistor, a first comparator, a first voltage divider resistor, and a second voltage divider resistor; The non-inverting input of the first comparator is connected to the temperature input pin of the battery protection chip, and the inverting input of the first comparator is connected to the series connection node of the first voltage divider resistor and the second voltage divider resistor. The first voltage divider resistor is connected to the positive terminal of the first voltage source, and the second voltage divider resistor is connected to the negative terminal of the first voltage source. The output of the first comparator is connected to the control terminal of the switching transistor, the input of the switching transistor is connected to the first resistor series node of the resistor series network, and the output of the switching transistor is connected to the second resistor series node of the resistor series network.

3. The overvoltage threshold adjustment circuit according to claim 1, characterized in that, The resistor series network includes a third voltage divider resistor, a fourth voltage divider resistor, a fifth voltage divider resistor, and a sixth voltage divider resistor connected in series. The series connection node of the third voltage divider resistor and the fourth voltage divider resistor is the first resistor series connection node, the series connection node of the fourth voltage divider resistor and the fifth voltage divider resistor is the second resistor series connection node, and the series connection node of the fifth voltage divider resistor and the sixth voltage divider resistor is the third resistor series connection node.

4. The overvoltage threshold adjustment circuit according to claim 1, characterized in that, The overvoltage protection module includes a second comparator; The non-inverting input of the second comparator is connected to the third resistor series node of the resistor series network, and the inverting input of the second comparator is connected to the second voltage source; Alternatively, the inverting input of the second comparator is connected to the third resistor series node of the resistor series network, and the non-inverting input of the second comparator is connected to the second voltage source.

5. The overvoltage threshold adjustment circuit according to claim 1, characterized in that, Also includes: A temperature detection module, wherein the temperature detection module is connected to the temperature input pin of the battery protection chip; The temperature detection module is used to convert the measured battery temperature into a voltage signal and input it to the temperature input pin of the battery protection chip.

6. The overvoltage threshold adjustment circuit according to claim 5, characterized in that, The temperature detection module includes a thermistor; The first end of the thermistor is connected to the negative terminal of the battery and the ground pin of the battery protection chip, respectively, and the second end of the thermistor is connected to the temperature input pin of the battery protection chip.

7. A battery protection chip, characterized in that, Includes the overvoltage threshold adjustment circuit as described in any one of claims 1-6.

8. The battery protection chip according to claim 7, characterized in that, Also includes: Over-temperature protection module, wherein the over-temperature protection module is connected to the temperature input pin of the battery protection chip; The temperature input pin of the battery protection chip is used to adjust the third input voltage of the over-temperature protection module according to temperature changes; The over-temperature protection module is used to trigger the battery's over-temperature protection based on the comparison result between the third input voltage and the third preset voltage.

9. The battery protection chip according to claim 8, characterized in that, The over-temperature protection module includes a third comparator, a seventh voltage divider resistor, an eighth voltage divider resistor, and a ninth voltage divider resistor; The non-inverting input of the third comparator is connected to the temperature input pin of the battery protection chip and the first terminal of the seventh voltage divider resistor, respectively; the second terminal of the seventh voltage divider resistor is connected to the third voltage source. The inverting input of the third comparator is connected to the series node of the eighth and ninth voltage divider resistors. The eighth voltage divider resistor is connected to the positive terminal of the fourth voltage source, and the ninth voltage divider resistor is connected to the negative terminal of the fourth voltage source.

10. A battery, characterized in that, Includes the battery protection chip as described in any one of claims 7-9.

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