Overcurrent protection circuit
By using a pure hardware solution with separate switching modules, overcurrent detection modules, latching modules, and delay modules, the problems of poor design flexibility and high cost of battery pack overcurrent protection are solved, achieving high reliability and low cost overcurrent protection.
Patent Information
- Application Number
- CN202423142100.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-19
- Publication Date
- 2025-11-18
- Estimated Expiration
- 2034-12-19
AI Technical Summary
Existing battery pack overcurrent protection solutions suffer from poor design flexibility, high cost, and low reliability, especially single-chip solutions and discrete device solutions, each with its own shortcomings.
A pure hardware solution that does not rely on a microcontroller is constructed by using a separately configured switching module, overcurrent detection module, latching module, and delay module. The overcurrent detection module detects overcurrent events, the latching module controls the switching module to disconnect, and the delay module provides a delay self-recovery function.
It improves the design flexibility and reliability of the circuit, reduces costs, and realizes overcurrent circuit breaking and delay self-recovery functions, adapting to customized adjustments for different needs.
Smart Images
Figure CN223567294U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to overcurrent protection technical field especially relates to an overcurrent protection circuit. BACKGROUND
[0002] At present, the application of battery pack is increasingly widespread. However, the battery pack can generate a large current in the working state, and if overcurrent problem occurs, the battery management system in the battery pack or other components in the system using the battery pack can be damaged, or thermal runaway phenomenon can occur, which forms a certain safety hazard to the system. Therefore, overcurrent protection of the battery pack is crucial.
[0003] At present, there are two schemes for mainstream overcurrent protection products: one is a single-chip scheme, which uses an overcurrent limiting chip for overcurrent protection. Although the single-chip scheme has high integration, the flexibility of circuit parameter adjustment is poor, which is not conducive to meeting customized needs, and the cost is high. The other is a discrete device scheme, which is usually composed of an overcurrent detection amplifier, a comparator and a microcontroller and other components. The discrete scheme relies on a microcontroller and a control program configured therein to realize overcurrent protection. Since it relies on a microcontroller and a program design, the design is relatively complex, the development cost is high, and the reliability is low. SUMMARY
[0004] The utility model provides a kind of overcurrent protection circuit to improve the design flexibility and reliability of overcurrent protection circuit, and reduce cost.
[0005] The utility model embodiment provides a kind of overcurrent protection circuit, comprising:
[0006] Switch module is connected between battery pack and load;
[0007] Overcurrent detection module is accessed overcurrent threshold;The overcurrent detection module is used to detect load current that the battery pack provides to the load, and outputs first control signal when the load current exceeds the overcurrent threshold;
[0008] Latching module, the clock end of the latching module is connected the output end of the overcurrent detection module, the input end of the latching module is accessed first power signal, and the output end of the latching module is connected the control end of the switch module;The latching module is used to output cut-off control signal according to the first control signal and the first power signal;The switch module is used to cut off according to the cut-off control signal;
[0009] a delay module, an input end of the delay module is connected to an output end of the latch module, and an output end of the delay module is connected to a reset end of the latch module; the delay module is configured to output a reset signal after a preset delay time after receiving the cutoff control signal; the latch module is configured to output a turn-on control signal according to the reset signal; and the switch module is configured to turn on according to the turn-on control signal.
[0010] Optionally, the switch module comprises a transistor, a first pole of the transistor is connected to the battery pack, a second pole of the transistor is connected to the load, and a gate of the transistor serves as a control end of the switch module.
[0011] Optionally, the transistor is a PMOS transistor.
[0012] Optionally, the overcurrent detection module comprises:
[0013] a current detection unit, connected between the switch module and the load, configured to detect a load current provided by the battery pack to the load;
[0014] a comparator, a first input end of the comparator is connected to an output end of the current detection unit, a second input end of the comparator is connected to the overcurrent threshold, and an output end of the comparator is connected to an output end of the overcurrent detection module; the comparator is configured to output the first control signal when the load current exceeds the overcurrent threshold.
[0015] Optionally, the current detection unit comprises:
[0016] a sampling resistor, connected between the switch module and the load;
[0017] a current detection amplifier, connected to the sampling resistor and an output end of the current detection unit respectively.
[0018] Optionally, the latch module comprises a D flip-flop, a clock end of the D flip-flop is connected to a clock end of the latch module, an input end of the D flip-flop is connected to an input end of the latch module, an output end of the D flip-flop is connected to an output end of the latch module, and a reset end of the D flip-flop is connected to a reset end of the latch module.
[0019] Optionally, a voltage of the first power supply signal is equal to a voltage of the cutoff control signal, the input end of the D flip-flop is directly connected to the input end of the latch module, and the output end of the D flip-flop is directly connected to the output end of the latch module.
[0020] or,
[0021] The voltage of the first power signal is equal to the voltage of the conduction control signal, and the latch module further comprises an inverter connected between the input end of the D flip-flop and the input end of the latch module or connected between the output end of the D flip-flop and the output end of the latch module.
[0022] Optionally, the delay module comprises a voltage monitor, wherein the input end of the voltage monitor is connected to the input end of the delay module, and the output end of the voltage monitor is connected to the output end of the delay module.
[0023] Optionally, the overcurrent protection circuit further comprises a gate drive module connected between the output end of the latch module and the control end of the switch module.
[0024] Optionally, the overcurrent protection circuit further comprises an alarm module connected to the output end of the latch module.
[0025] In the overcurrent protection circuit provided by the embodiment of the present application, the switch module, the overcurrent detection module, the latch module and the delay module are arranged separately, which is equivalent to providing a separate pure hardware solution without microcontroller and software, and the cooperation logic between the functional modules is simple, the design complexity can be effectively reduced, the circuit reliability can be improved, and the cost can be reduced. Specifically, based on the overcurrent detection module, whether an overcurrent event occurs can be detected, when the overcurrent event occurs, the overcurrent detection module can control the latch module to control the switch module to be disconnected in time, so as to disconnect the load in time and realize the overcurrent circuit breaking function; and the delay module can control the latch module to control the switch module to be turned on after a preset delay time after the overcurrent event occurs, and the function of delay self-recovery is provided. Compared with the single-chip solution with high integration, the separate solution adopted by the embodiment of the present application is beneficial to flexible adjustment of parameters such as the overcurrent threshold and the preset delay time, and the circuit maintenance is more convenient, and when any functional module fails, the functional module can be independently repaired or replaced, so that the circuit reliability and service life are improved.
[0026] It should be understood that the content described in this part is not intended to identify the key or important features of the embodiments of the present application, nor is it used to limit the scope of the present application. Other features of the present application will become apparent from the following description. BRIEF DESCRIPTION OF DRAWINGS
[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creating any creative labor.
[0028] Figure 1 is a structural schematic diagram of an overcurrent protection circuit provided by an embodiment of the present application;
[0029] Figure 2 is a structural schematic diagram of another overcurrent protection circuit provided by an embodiment of the present application;
[0030] Figure 3 is a structural schematic diagram of a latch module provided by an embodiment of the present application. DETAILED DESCRIPTION
[0031] In order to make the person skilled in the art better understand the present application scheme, the technical scheme in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by the person skilled in the art without creative labor should belong to the scope of protection of the present application.
[0032] It should be noted that the terms "first", "second" and the like in the specification and claims of the present application and the above drawings are used to distinguish similar objects, and do not have to be used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion.
[0033] The embodiment of the present application provides an overcurrent protection circuit, which can disconnect the load in time when the overcurrent event occurs, and has the function of delay recovery. Figure 1 is a structural schematic diagram of an overcurrent protection circuit provided by an embodiment of the present application, referring to Figure 1 The overcurrent protection circuit 100 includes: a switch module 10, an overcurrent detection module 20, a latch module 30 and a delay module 40.
[0034] The switch module 10 is connected between the battery pack 200 and the load 300. The overcurrent detection module 20 is connected to the overcurrent threshold I1. The overcurrent detection module 20 is configured to detect the load current IL provided by the battery pack 200 to the load 300 and output a first control signal SC1 when the load current exceeds the overcurrent threshold I1. The clock terminal 31 of the latch module 30 is connected to the output terminal 23 of the overcurrent detection module 20, the input terminal 32 of the latch module 30 is connected to the first power signal V1, and the output terminal 33 of the latch module 30 is connected to the control terminal 13 of the switch module 10. The latch module 30 is configured to output an off control signal OFF according to the first control signal SC1 and the first power signal V1. The switch module 10 is configured to be turned off according to the off control signal OFF. The input terminal 41 of the delay module 40 is connected to the output terminal 33 of the latch module 30, and the output terminal 42 of the delay module 40 is connected to the reset terminal 34 of the latch module 30. The delay module 40 is configured to output a reset signal RE after a preset delay time after receiving the off control signal OFF. The latch module 30 is configured to output an on control signal ON according to the reset signal RE. The switch module 10 is configured to be turned on according to the on control signal ON.
[0035] For example, the first terminal 11 of the switch module 10 is connected to the battery pack 200, the second terminal 12 of the switch module 10 is connected to the load 300, and the switch module 10 is configured to be turned on or off according to the voltage of the control terminal 13. The switch module 10 can include any type of controllable switching device such as a transistor, a relay, or a switch chip to control whether the battery pack 200 is connected to the load 300 and whether the battery pack 200 supplies power to the load 300.
[0036] The detection terminal 21 of the overcurrent detection module 20 is coupled between the second terminal 12 of the switch module 10 and the load 300, for example, to receive the load current IL. The reference terminal 22 of the overcurrent detection module 20 is connected to the overcurrent threshold I1. The overcurrent detection module 200 can have a comparison structure inside to compare the load current IL and the overcurrent threshold I1 and output the first control signal SC1 when the load current IL is greater than the overcurrent threshold I1. That is, when the overcurrent detection module 20 outputs the first control signal SC1, it indicates that an overcurrent event has occurred. For example, when the load current IL does not reach the overcurrent threshold I1, the overcurrent detection module 20 can output a signal different from the voltage of the first control signal SC1 or not output.
[0037] The latch module 30 can include a latch structure with trigger output and reset function. The latch module 30 is triggered when receiving the first control signal SC1, thereby outputting the off control signal OFF according to the first power signal V1. For example, the first power signal V1 can be directly outputted, or outputted after voltage conversion. The specific output structure can be determined according to the relationship between the off voltage of the switch module 10 and the first power signal V1. After outputting the off control signal OFF, the latch module 30 can latch the state. At this time, no matter whether the signal of the clock end 31 changes, the output end 33 of the latch module 30 continuously outputs the off control signal OFF until the reset end 34 receives the reset signal RE. The output end 33 of the latch module 30 is converted to output the on control signal ON. For example, the latch module 30 defaults to output the on control signal ON. When the clock end 31 receives the first control signal SC1 next time after the reset, the latch module 30 can be converted to output the off control signal OFF again. The off control signal OFF and the on control signal ON have different voltages. The off control signal OFF can have a voltage related to the off voltage of the switch module 10, for controlling the switch module 10 to turn off. The on control signal ON can have a voltage related to the on voltage of the switch module 10, for controlling the switch module 10 to turn on.
[0038] The delay module 40 starts the delay function when the input end 41 receives the off control signal OFF. After a preset delay time, the reset signal RE is outputted from the output end 42 to control the latch module 30 to reset and restore the output of the on control signal ON. Thus, it is equivalent to controlling the switch module 10 to turn on after a preset delay time after the overcurrent control switch module 10 turns off, so that the overcurrent protection circuit has the function of delay recovery. Since the sudden surge of load current IL in the working process of electronic circuit is often caused by accidental faults, most accidental faults can be solved by re-powering after power-off. By setting the delay module 40, the self-recovery function of overcurrent protection is provided. For example, the delay module 40 can include any timing structure. The structure outputs the reset signal RE after a set time (i.e. a preset delay time) after being triggered by the off control signal OFF. For example, the delay time can be set by a capacitor or other devices. It can be understood that the delay module 40 controls the voltage output by the latch module 30 by controlling the working state of the latch module 30. The voltage of the input end 41 of the delay module 40 is not affected in the working process of the delay module 40, i.e. the voltage of the off control signal OFF is not affected by the delay module 40, so that the off control signal OFF can quickly control the switch module 10 to turn off, and the switch module 10 is continuously controlled to remain off within the preset delay time, thereby ensuring the stable off function of the switch module 10.
[0039] It should be noted that the switch module 10, the overcurrent detection module 20, the latch module 30 and the delay module 40 are all function modules arranged separately. The overcurrent threshold I1, the first power supply voltage V1 and the preset delay time can all be adjusted according to actual needs. Since the overcurrent detection module 20, the latch module 30 and the delay module 40 are all relatively independent, the related parameters of the three can be flexibly and conveniently adjusted, and will not affect other function modules.
[0040] Exemplarily, the overcurrent protection circuit can be applied to a satellite; the battery pack 200 can be a lithium battery pack, which is used as an energy source of an electrical system in the satellite, and the load 300 can be a load of the electrical system in the satellite. Exemplarily, the positive electrode of the battery pack 200 is used for connecting a positive power supply end of the load 300, and a negative power supply end of the load 300 and a negative electrode of the battery pack 200 can both be grounded.
[0041] In the overcurrent protection circuit provided by the embodiment of the utility model, including separately arranged switch module 10, overcurrent detection module 20, latch module 30 and delay module 40, equivalent to provide a kind of removal microcontroller's separate pure hardware scheme, not dependent on microcontroller and software, the cooperation logic between each function module is simple, can effectively reduce design complexity, improve circuit reliability, and reduce cost. Specifically, based on overcurrent detection module 20 can detect whether overcurrent event occurs, when overcurrent event occurs, overcurrent detection module 20 can control latch module 30 and control switch module 10 to disconnect in time, to disconnect load in time, realize overcurrent circuit breaking function;And delay module 40 can control latch module 30 to control switch module 10 to conduct after preset delay time after overcurrent event, provide the function of delay self-recovery. And, compared with the single-chip scheme with higher integration, the separate scheme is adopted in the embodiment of the utility model, which is conducive to flexible adjustment of overcurrent threshold I1 and preset delay time and other parameters, and circuit maintenance is more convenient, and any function module fault can be independently repaired or replaced, to improve circuit reliability and service life.
[0042] The specific structure of each function module in the overcurrent protection circuit will be exemplarily described below, but not as a limitation of the utility model.
[0043] Figure 2 is another structure diagram of overcurrent protection circuit provided by the embodiment of the utility model. Referring to Figure 2In an embodiment, the switch module 10 comprises a transistor, a first pole of the transistor is connected to the battery pack 200, a second pole of the transistor is connected to the load 300, and a gate of the transistor is used as a control terminal of the switch module 10. In this embodiment, the transistor is used to form the switch module 10, which can avoid the problems of contact wear and oxidation compared with the contact switch, thereby prolonging the service life of the circuit. In addition, the switching speed of the switch module can be improved, and the reliability of the circuit can be improved. For example, the transistor is a MOS transistor, such as a PMOS transistor, which can complete the circuit breaking within microseconds or even hundreds of nanoseconds after the overcurrent event occurs, thereby achieving reliable overcurrent protection.
[0044] On the basis of the above-mentioned embodiments, the overcurrent detection module 20 comprises a current detection unit 210 and a comparator 220. The current detection unit 210 is connected between the switch module 10 and the load 300, and is configured to detect the load current provided by the battery pack 200 to the load 300 and output the load current. The first input terminal of the comparator 220 is connected to the output terminal of the current detection unit 210, the second input terminal of the comparator 220 is connected to the overcurrent threshold I1, and the output terminal of the comparator 220 is connected to the output terminal of the overcurrent detection module 20. The comparator 220 is configured to compare the load current with the overcurrent threshold I1, and output a first control signal when the load current exceeds the overcurrent threshold. For example, when the load current does not reach the overcurrent threshold, the comparator 220 does not output.
[0045] On the basis of the above-mentioned embodiments, the current detection unit 210 can be any structure capable of detecting current. For example, the current detection unit 210 can be a current sensor, the detection component of which is used as a sampling terminal of the overcurrent detection module 20, and can be sleeved on the connecting line between the switch module 10 and the load 300 to achieve detection of the load current.
[0046] Alternatively, referring to Figure 2 , the current detection unit 210 comprises a sampling resistor 211 and a current detection amplifier 212. The sampling resistor 211 is connected between the switch module 10 and the load 300, and both ends of the sampling resistor 211 are used as a sampling terminal of the overcurrent detection module 20. The current detection amplifier 212 is connected to the sampling resistor 211 and the output terminal of the current detection unit 210, respectively. For example, both ends of the sampling resistor 211 are connected to the current detection amplifier 212. The sampling resistor 211 is a resistor with a known resistance value, and the current detection amplifier 212 can obtain the size of the load current by detecting the voltage difference between the two ends of the sampling resistor 211 and combining the resistance value of the sampling resistor 211. For example, the resistance value of the sampling resistor 211 is very small to avoid consuming too much power on the sampling resistor. The current detection amplifier 212 can amplify the voltage difference between the two ends of the sampling resistor 211 and then convert it into a current signal, for example, output a current signal with the same size as the load current.
[0047] On the basis of the above-mentioned embodiments, optionally, the latch module 30 comprises a D flip-flop 310. A clock input pin of the D flip-flop 310 is connected to the clock terminal of the latch module 30 as the clock terminal of the D flip-flop 310; a data input pin of the D flip-flop 310 is connected to the input terminal of the latch module 30 as the input terminal of the D flip-flop 310; an output pin of the D flip-flop 310 is connected to the output terminal of the latch module 30 as the output terminal of the D flip-flop 310; and a reset pin of the D flip-flop 310 is connected to the reset terminal of the latch module 30 as the reset terminal of the D flip-flop 310. In this embodiment, the D flip-flop 310 provides the functions of triggering and resetting the latch, so that the structure of the latch module 30 is simple and easy to implement, and the circuit can be prevented from repeatedly conducting and shutting off, thereby protecting the safety of the circuit.
[0048] On the basis of the above-mentioned embodiments, optionally, according to the voltage of the first power signal V1, the structure of the latch module 30 can be flexibly adjusted on the basis of the D flip-flop 310, so that the latch module 30 can correctly output the off control signal OFF when receiving the first control signal SC1.
[0049] Specifically, in one embodiment, optionally, the voltage of the first power signal V1 is equal to the voltage of the off control signal OFF, and then the input terminal of the D flip-flop 310 is directly connected to the input terminal of the latch module 30, and the output terminal of the D flip-flop 310 is directly connected to the output terminal of the latch module 30, as shown in Figure 2 .
[0050] In another embodiment, optionally, the voltage of the first power signal V1 is equal to the voltage of the on control signal ON. Then, as shown in Figure 3 , the latch module 30 further comprises an inverter 320, that is, the latch module 30 can comprise the D flip-flop 310 and the inverter 320. In this embodiment, the clock terminal CLK of the D flip-flop 310 is connected to the clock terminal of the latch module 30, and the reset terminal CLR of the D flip-flop 310 is connected to the reset terminal of the latch module 30. It can be understood that the upper horizontal line marked on the reset terminal CLR indicates that the port is low active. As shown in Figure 3 , the input terminal D of the D flip-flop 310 can be connected to the input terminal of the latch module 30, and the inverter 320 is connected between the output terminal Q of the D flip-flop 310 and the output terminal of the latch module 30. Alternatively, the inverter 320 can be connected between the input terminal D of the D flip-flop 310 and the input terminal of the latch module 30, and the output terminal Q of the D flip-flop 310 is connected to the output terminal of the latch module 30.
[0051] On the basis of the above-mentioned embodiments, optionally, the delay module 40 comprises a voltage monitor 410, for example, a voltage monitor with a delay function. The input end of the voltage monitor 410 is connected to the input end of the delay module 40, and the output end of the voltage monitor 410 is connected to the output end of the delay module 40. Exemplarily, the delay time of the voltage monitor 410 is adjustable, and the preset delay time can be set according to the characteristics of the load 300, for example, set to 3-5s. Compared with directly setting an RC delay structure at the output end of the latch module 30, by setting the voltage monitor 410, the delay module 40 does not directly act on the voltage at the output end of the latch module 30, but changes the voltage at the output end of the latch module 30 by controlling the working state of the latch module 30; in this way, it can be avoided that a relatively long delay is caused by the latch module 30 outputting the cutoff control signal OFF, and it is ensured that the switch module 10 can be controlled to be turned off within microseconds after an overcurrent event occurs.
[0052] On the basis of the above-mentioned embodiments, optionally, the overcurrent protection circuit 100 further comprises a gate drive module 50 connected between the output end of the latch module 30 and the control end of the switch module 10. The gate drive circuit 50 can convert the cutoff control signal into a cutoff voltage of the switch module 10, and convert the conduction control signal into a conduction voltage of the switch module 10. The gate drive module 50 can be formed by any gate drive circuit, which can effectively improve the driving capability of the output end of the latch module 30, especially in the case that the voltage output by the latch module 30 cannot reach the conduction / cutoff voltage of the switch module 10 and is insufficient to drive the switch module 10 to turn on / off, by setting the gate drive module 50, it can be ensured that the on / off state of the switch module 10 can be normally controlled, and the selection range of devices in the switch module 10 and the latch module 30 is expanded.
[0053] On the basis of the above-mentioned embodiments, optionally, the overcurrent protection circuit 100 further comprises an alarm module 60 connected to the output end of the latch module 30. The alarm module 60 can be used for overcurrent alarm when receiving the cutoff control signal OFF. The alarm module 60 can comprise a buzzer, a light-emitting diode or a vibrator, and can be powered when receiving the cutoff control signal OFF, and perform overcurrent alarm by buzzing, emitting light or vibrating.
[0054] The following will be described in combination with Figure 2The specific working process of the overcurrent protection circuit 100 can be as follows: using the current detection amplifier 212 to detect the load current flowing through the sampling resistor 211, and comparing it with the set overcurrent threshold I1. If the load current exceeds the overcurrent threshold I1, the comparator 212 sends the high-level first control signal to the clock end of the D flip-flop 310, controls the D flip-flop 310 to output the high-level first power supply signal V1 connected to the input end as the off control signal, and the gate drive module 50 controls the PMOS pipe to be turned off according to the off control signal; at the same time, the voltage monitor 410 receives the off control signal, starts the delay output function, and the alarm module 60 is powered on to perform overcurrent alarm; then, the D flip-flop 310 is in the latching state, keeps the voltage at the output end in the high-level state, and continuously sends the off control signal to the gate drive module 50; after a preset delay time, the voltage monitor 410 outputs the low-level reset signal, controls the output end of the D flip-flop 310 to be reset to the low level (namely, outputs the on control signal), and the gate drive module 50 controls the PMOS pipe to restore conduction according to the on control signal.
[0055] In summary, the embodiment of the utility model provides a kind of high discrete pure hardware overcurrent protection scheme, with the following advantages:
[0056] 1) higher discrete degree and design flexibility. The overcurrent protection circuit can flexibly adjust the performance and function of each module and device according to the needs of the protected product, meeting the customized needs of product circuit protection.
[0057] 2) low cost. Unlike traditional discrete solutions that require microcontrollers, this solution only requires a small number of devices, and these devices are usually low in price.
[0058] The above specific embodiments do not constitute a limitation on the scope of protection of the utility model. Those skilled in the art should understand that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement within the spirit and principles of the utility model should be included in the scope of protection of the utility model.
Claims
1. An overcurrent protection circuit, characterized in that, include: The switch module connects the battery pack and the load. Overcurrent detection module, connected to overcurrent threshold; The overcurrent detection module is used to detect the load current supplied by the battery pack to the load, and output a first control signal when the load current exceeds the overcurrent threshold; A latch module is provided, wherein the clock terminal of the latch module is connected to the output terminal of the overcurrent detection module, the input terminal of the latch module is connected to a first power supply signal, and the output terminal of the latch module is connected to the control terminal of the switching module; the latch module is used to output a cutoff control signal according to the first control signal and the first power supply signal; the switching module is used to turn off according to the cutoff control signal. A delay module, wherein the input terminal of the delay module is connected to the output terminal of the latch module, and the output terminal of the delay module is connected to the reset terminal of the latch module; The delay module is used to output a reset signal after a preset delay time following the receipt of the cutoff control signal; the latch module is used to output a conduction control signal according to the reset signal; and the switch module is used to conduct according to the conduction control signal.
2. The overcurrent protection circuit according to claim 1, characterized in that, The switching module includes a transistor, the first terminal of which is connected to the battery pack, the second terminal of which is connected to the load, and the gate of which serves as the control terminal of the switching module.
3. The overcurrent protection circuit according to claim 2, characterized in that, The transistor is a PMOS transistor.
4. The overcurrent protection circuit according to claim 1, characterized in that, The overcurrent detection module includes: A current detection unit, connected between the switching module and the load, is used to detect the load current supplied by the battery pack to the load; The comparator has its first input connected to the output of the current detection unit, its second input connected to the overcurrent threshold, and its output connected to the output of the overcurrent detection module. The comparator is used to output the first control signal when the load current exceeds the overcurrent threshold.
5. The overcurrent protection circuit according to claim 4, characterized in that, The current detection unit includes: A sampling resistor is connected between the switching module and the load; A current sensing amplifier is connected to the sampling resistor and the output terminal of the current sensing unit, respectively.
6. The overcurrent protection circuit according to claim 1, characterized in that, The latch module includes: a D flip-flop; the clock terminal of the D flip-flop is connected to the clock terminal of the latch module, the input terminal of the D flip-flop is connected to the input terminal of the latch module, the output terminal of the D flip-flop is connected to the output terminal of the latch module, and the reset terminal of the D flip-flop is connected to the reset terminal of the latch module.
7. The overcurrent protection circuit according to claim 6, characterized in that, The voltage of the first power supply signal is equal to the voltage of the cutoff control signal. The input terminal of the D flip-flop is directly connected to the input terminal of the latch module, and the output terminal of the D flip-flop is directly connected to the output terminal of the latch module. or, The voltage of the first power supply signal is equal to the voltage of the conduction control signal. The latch module further includes an inverter connected between the input terminal of the D flip-flop and the input terminal of the latch module, or connected between the output terminal of the D flip-flop and the output terminal of the latch module.
8. The overcurrent protection circuit according to claim 1, characterized in that, The delay module includes a voltage monitor; the input terminal of the voltage monitor is connected to the input terminal of the delay module, and the output terminal of the voltage monitor is connected to the output terminal of the delay module.
9. The overcurrent protection circuit according to claim 1, characterized in that, Also includes: A gate driving module is connected between the output terminal of the latch module and the control terminal of the switching module.
10. The overcurrent protection circuit according to claim 1, characterized in that, Also includes: An alarm module is connected to the output of the latch module.