Over-current protection self-checking circuit and over-current protection self-checking method

Abstract

The invention provides a self-checking circuit for overcurrent protection and a self-checking method for overcurrent protection. The signal input end of a self-checking trigger module is connected with the first output end of a control module, and the output end of the self-checking trigger module is connected with the input end of a comparator module; the output end of the comparator module is connected with the input end of the control module; the first input end of the NAND gate module is connected with the second output end of the control module, and the second input end of the NAND gate module is connected with the output end of the comparator module; and the output end of the NAND gate module is connected with the input end of the driving module. During self-checking, the control module controls the self-checking trigger module to output a level signal to the comparator module through a self-checking signal so as to simulate current input, and the comparator module judges whether input level voltage is within a preset range and outputs a comparison result to the control module. The control module can determine the state of the circuit according to the received level signal, and completes the self-inspection of the overcurrent protection circuit.

Description

Technical Field

[0001] The present application relates to the field of motors, and in particular to a self-test circuit for overcurrent protection and a self-test method for overcurrent protection. Background Art

[0002] Motor overcurrent protection is a very important safety measure in motor drive and control systems. It prevents the motor from being damaged due to overload or failure by detecting the current value when the motor is working. Overcurrent protection can effectively extend the service life of the motor, ensure the safe operation of the equipment, and prevent the motor from overheating, burning or causing other more serious failures due to long-term overcurrent.

[0003] The existing motor overcurrent protection circuit directly detects the sampled current through a comparator, and when it is higher than the threshold, it outputs a high-level signal to shut down the drive module to achieve the purpose of overcurrent protection. However, the entire circuit does not have a functional safety self-test function, and it is impossible to know whether the protection circuit is in a normal state or an abnormal state. There is a situation of false protection or no protection caused by an abnormal protection circuit.

[0004] Therefore, how to perform self-test on the overcurrent protection circuit is an urgent problem to be solved. Summary of the invention

[0005] The present application provides an overcurrent protection self-test circuit and an overcurrent protection self-test method, which are used to perform a self-test on the overcurrent protection circuit to determine whether the overcurrent protection circuit is in an abnormal state.

[0006] In a first aspect, the present application provides a self-check circuit for overcurrent protection, comprising: a self-check trigger module, a comparator module, a control module, a NAND gate module and a drive module;

[0007] The signal input end of the self-test trigger module is connected to the first output end of the control module, the output end of the self-test trigger module is connected to the input end of the comparator module, and the self-test trigger module is used to input the self-test voltage in the circuit to the comparator module when receiving the self-test signal of the control module;

[0008] The output end of the comparator module is connected to the input end of the control module, and the comparator module is used to compare the input self-test voltage with a preset voltage range;

[0009] The first input end of the NAND gate module is connected to the second output end of the control module, and the second input end of the NAND gate module is connected to the output end of the comparator module;

[0010] The output end of the NAND gate module is connected to the input end of the driving module.

[0011] Optionally, the comparator module includes a first comparator and a second comparator;

[0012] The first comparator is used to compare the input self-test voltage with the upper limit of the voltage range;

[0013] The second comparator is used to compare the input self-test voltage with the lower limit of the voltage range.

[0014] Optionally, the self-test trigger module includes a self-test switch and a voltage-dividing resistor;

[0015] When the self-test signal is received, the self-test switch is turned on, and the self-test voltage formed by dividing the power supply voltage VCC by the voltage-dividing resistor is output to the comparator module.

[0016] Optionally, the self-test switch includes a high-side switch and a low-side switch;

[0017] The high side switch comprises a first transistor and a second transistor;

[0018] The low side switch comprises a third transistor;

[0019] When the high-side switch and the low-side switch are both turned on, the self-test switch is turned on.

[0020] Optionally, the sampling current is connected to the input terminal of the comparator module.

[0021] In a second aspect, the present application further provides a self-test method for overcurrent protection, which is applied to the self-test circuit for overcurrent protection as described in any one of the first aspects, and the method comprises:

[0022] When the control module enters the self-test mode, it outputs a self-test signal to the self-test trigger module;

[0023] The self-test trigger module receives the self-test signal and outputs a self-test voltage to the comparator module;

[0024] The comparator module compares the self-test voltage with a preset voltage range to obtain a comparison result;

[0025] The comparator module sends the comparison result to the control module;

[0026] The control module determines a state of the overcurrent protection circuit according to the comparison result, and the state includes a normal state or an abnormal state.

[0027] Optionally, if the self-test trigger module includes: a first transistor and a high-side switch composed of the first transistor, a low-side switch composed of a third transistor, and a resistor, and the self-test signal includes a high-level HI signal and a high-level LO signal, then the control module outputs the self-test signal to the self-test trigger module, including:

[0028] The control module outputs a high-level HI signal to the high-side switch to turn on the high-side switch;

[0029] The control module outputs a high-level LO signal to the low-side switch to turn on the low-side switch.

[0030] Optionally, if the comparator module includes a first comparator and a second comparator, the comparator module compares the self-test voltage with a preset voltage range to obtain a comparison result, including:

[0031] The first comparator compares the self-test voltage with an upper limit of a preset voltage range;

[0032] If the self-test voltage is greater than the upper limit of the voltage range, outputting a first result of a low level;

[0033] If the self-test voltage is less than or equal to the upper limit of the voltage range, outputting a first result of a high level;

[0034] The second comparator compares the self-test voltage with a lower limit of a preset voltage range;

[0035] If the self-test voltage is less than the lower limit of the voltage range, outputting a second result of a low level;

[0036] If the self-test voltage is greater than or equal to the lower limit of the voltage range, outputting a second result of a high level;

[0037] The comparison result is determined according to the first result and the second result.

[0038] Optionally, determining the comparison result according to the first result and the second result includes:

[0039] If any one of the first result and the second result is a low level, the comparison result is a low level; otherwise, the comparison result is a high level.

[0040] Optionally, if the pre-designed self-test voltage is less than the lower limit of the voltage range, or greater than the upper limit of the voltage range, the control module determines the state of the overcurrent protection circuit according to the comparison result, including:

[0041] If the comparison result is a low level, the control module determines that the overcurrent protection circuit is in a normal state;

[0042] If the comparison result is a high level, the control module determines that the overcurrent protection circuit is in an abnormal state.

[0043] Optionally, the method further includes:

[0044] When the control module exits the self-test mode, it stops outputting the self-test signal and outputs a high-level signal to the first input terminal of the NAND gate module;

[0045] The comparator module receives a sampled current, compares a voltage of the sampled current with the voltage range, and obtains a sampled comparison result, wherein the sampled comparison result is used to indicate a high level or a low level;

[0046] Outputting the sampling comparison result to the second input terminal of the NAND gate module;

[0047] If either the first output terminal or the second input terminal of the NAND gate module is at a low level, the NAND gate module outputs a high level to the driving module to control the driving module to stop working.

[0048] The embodiments of the present application provide an overcurrent protection self-test circuit and an overcurrent protection self-test method. During self-test, the self-test trigger module outputs a level signal to the comparator module to simulate the input of current. The comparator module outputs the level signal to the control module. The control module can determine the state of the circuit based on the received level signal, thereby completing the self-test of the overcurrent protection circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0050] Figure 1 A schematic diagram of the structure of a self-test circuit for overcurrent protection provided in this application Figure 1 ;

[0051] Figure 2 A schematic diagram of the structure of a self-test circuit for overcurrent protection provided in this application Figure 2 ;

[0052] Figure 3 A schematic diagram of the structure of a self-test circuit for overcurrent protection provided in this application Figure 3 ;

[0053] Figure 4 A schematic diagram of the structure of an example of a self-checking circuit for overcurrent protection provided by the present application;

[0054] Figure 5 A schematic diagram of the structure of the control module provided for this application;

[0055] Figure 6 A schematic diagram of the structure of the electronic device provided in this application.

[0056] The above drawings have shown clear embodiments of the present application, which will be described in more detail later. These drawings and text descriptions are not intended to limit the scope of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0057] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0058] The existing motor overcurrent protection circuit does not have a functional safety self-check function. Generally, the sampled current is directly detected through a comparator. When it is higher than the threshold, a high-level signal is output to shut down the drive module to achieve the purpose of overcurrent protection. However, the entire circuit does not have a functional safety self-check function, and it is impossible to know whether the protection circuit is in a normal state or an abnormal state, and there is a lack of design for the functional safety of the vehicle-mounted electronic circuit.

[0059] In view of the above problems, the present application adds a self-test function on the basis of the overcurrent protection circuit, mainly by turning on the switch in the designed self-test trigger module through the control module, and the power supply voltage (Volt Current Condenser, abbreviated as: VCC) is input into the comparator for comparison after being stepped down, and the comparison result is returned to the control module. If the control module obtains the expected result, it means that the overcurrent protection circuit is working normally. If an unexpected result is obtained, it means that the overcurrent protection circuit is abnormal.

[0060] This application is applicable to overcurrent protection of AC voltage type current signals. It can not only cut off the output of the driving signal by the circuit itself, but also control the output of the driving signal to be cut off through the control module. The overcurrent protection circuit also includes a functional safety self-test function, which can self-test the circuit and improve the reliability and intelligence of the circuit.

[0061] The technical solution of the present application and how the technical solution of the present application solves the above-mentioned technical problems are described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0062] Figure 1 A schematic diagram of the structure of a self-test circuit for overcurrent protection provided in this application Figure 1 ,like Figure 1As shown, it includes: a self-test trigger module, a comparator module, a control module, a NAND gate module and a drive module;

[0063] The signal input end of the self-test trigger module is connected to the first output end of the control module. The control module sends a self-test signal to the signal input end of the self-test trigger module through the output end. After receiving the self-test signal, the self-test trigger module turns on the switch in the module, so that the VCC voltage generates a self-test voltage after being divided by the resistance of the self-test trigger module.

[0064] The output end of the self-test trigger module is connected to the input end of the comparator module. The self-test trigger module is used to input the self-test voltage in the circuit to the comparator module after the switch is turned on when receiving the self-test signal from the control module.

[0065] After receiving the self-test voltage, the comparator module compares the self-test voltage with the preset voltage range to obtain a comparison result. The output end of the comparator module is connected to the input end of the control module on the one hand to transmit the comparison result; on the other hand, it is connected to the NAND gate module to achieve protection in normal overcurrent protection.

[0066] The first input end of the NAND gate module is connected to the second output end of the control module, and the second input end of the NAND gate module is connected to the output end of the comparator module.

[0067] The output end of the NAND gate module is connected to the input end of the driving module.

[0068] In addition, the sampling current flows in from the input module of the comparator so that the overcurrent protection circuit can work normally.

[0069] Through the scheme of the present application, during self-test, the self-test trigger module will output a level signal to the comparator module to simulate the input of current. The comparator module outputs the level signal to the control module. The control module can determine the state of the circuit based on the received level signal, thereby completing the self-test of the overcurrent protection circuit.

[0070] The self-test voltage, or self-test current, output by the self-test trigger module is related to the resistor design in the self-test trigger module.

[0071] Preferably, the generated self-test voltage may not be within the preset voltage range, so that the input of abnormal current or abnormal voltage can be simulated to check whether the protection circuit can play the role of overcurrent protection.

[0072] In another embodiment, the generated self-test voltage may also be within a preset voltage range, so that it can be checked whether the protection circuit can work normally under normal current conditions.

[0073] In another way, the control module can control different switches in the self-test trigger module to make different resistors act, so that the self-test voltage generated can change. During self-test, the abnormal voltage input situation can be simulated first, and then the normal voltage input situation can be simulated to perform detection under multiple voltages.

[0074] When the control module enters the self-test mode, it outputs a self-test signal to the self-test trigger module.

[0075] For the self-test trigger module, the circuit of the self-test trigger module includes a self-test switch and a voltage divider resistor, wherein the self-test switch can be one or more. When a self-test signal is received, the self-test switch is turned on, and the self-test voltage formed by the VCC voltage being divided by the voltage divider resistor is output to the comparator module.

[0076] In one implementation, only one self-test switch is used in the circuit of the self-test trigger module. When a self-test signal is received, the switch is closed, and the VCC voltage is divided by a voltage divider resistor to form a self-test voltage. In another implementation, there are multiple self-test switches in the circuit of the self-test trigger module, and they are connected in series or in parallel. This can enhance the fault tolerance of the system. For example, when multiple switches are connected in series, the self-test voltage can only be formed when all switches are turned on; if they are connected in parallel, it can be ensured that even if one switch fails, the other switches can still trigger the self-test process.

[0077] A specific circuit structure of the self-test trigger module is introduced below with an embodiment.

[0078] Figure 2 A schematic diagram of the structure of a self-test circuit for overcurrent protection provided in this application Figure 2 ,like Figure 2 As shown, the self-test trigger module includes: a high-side switch composed of a first transistor Q1 and a second transistor Q2, a low-side switch composed of a third transistor Q3, and a resistor;

[0079] The self-test trigger module can have multiple resistors. Figure 2 Two resistors, a first resistor R2 and a second resistor R3, are shown in FIG.

[0080] The control module outputs a high-level HI signal to the high-side switch to turn on the high-side switch; the control module outputs a high-level LO signal to the low-side switch to turn on the low-side switch.

[0081] After the high-side switch and the low-side switch are both turned on, the self-test voltage obtained by dividing the VCC voltage by the first resistor and the second resistor is output to the comparator module.

[0082] The magnitude of the self-test voltage is related to the magnitude of the first resistor and the second resistor. For example, assuming that the normal voltage range is 0.6-4.4V, the first resistor and the second resistor can be adjusted to generate a self-test voltage of 0.5V to simulate an abnormal situation and check whether the overcurrent protection circuit functions normally under abnormal conditions.

[0083] Figure 3 A schematic diagram of the structure of a self-test circuit for overcurrent protection provided in this application Figure 3 ,like Figure 3 As shown, the comparator includes a first comparator and a second comparator.

[0084] The first comparator is used to compare the input self-test voltage with the upper limit of the voltage range. If the self-test voltage is higher than the upper limit of the voltage range, the comparator module will output a low-level first result, otherwise it will output a high-level first result.

[0085] The second comparator is used to compare the input self-test voltage with the lower limit of the voltage range. If the self-test voltage is lower than the lower limit of the voltage range, the comparator module will output a low-level second result, otherwise it will output a high-level second result.

[0086] If either the first comparator or the second comparator outputs a low level comparison result, it means that the voltage is abnormal and finally outputs a low level.

[0087] The following introduces the self-detection circuit of overcurrent protection, the self-detection method of overcurrent protection and the overcurrent protection method with specific examples.

[0088] Figure 4 A schematic diagram of an example of a self-checking circuit for overcurrent protection provided by the present application is shown in FIG. Figure 4 As shown, during self-test, there is no sampling current input.

[0089] The self-test trigger module mainly includes a high-side switch composed of transistors Q1 and Q2 and a low-side switch composed of transistor Q3. When the sampling current is not input, when entering the self-test mode, the HI and LO signals output by the control module become high level, the high-side switch and the low-side switch are both turned on, and the self-test module will output a VCC voltage divided by R2 and R3 to form a signal lower than the REFL level to the comparator module. The comparator module will output a low-level signal to the control module. After obtaining it, the control module determines that the circuit is normal and completes the self-test of the circuit. When the self-test mode is not entered, the signals HI and LO are both in low-level mode.

[0090] The comparator module includes comparator 1 and comparator 2. The sampling current is input to the inverting terminal of comparator 1 and the non-inverting terminal of comparator 2. The non-inverting terminal of comparator 1 is connected to the high voltage reference signal REFH, and the inverting terminal of comparator 2 is connected to the low voltage reference signal REFL. Because the detected sampling current is an AC sinusoidal signal with a DC bias, as long as the sampling current is higher than the level REFH or lower than REFL, the comparator module will output a low level, indicating that the current is abnormal, thereby triggering the protection function of the circuit. When the sampling current level is between REFL and REFH, the current is considered normal. When the current is normal, the comparator module outputs a high level. The signal output by the comparator module is simultaneously connected to pin 2 of the control module and the NAND gate module.

[0091] A comparator is an electronic component that compares two input signals and outputs a logic level (usually high or low) that is the opposite of the input signal. The comparator works like a "switch" that changes its output state when the input signal exceeds a certain threshold.

[0092] The control module mainly includes an MCU control chip, which is used to receive signals and output control signals. The trigger signals HI and LO of the self-test function are output by the control module. The signal output by the comparator module will be input into the control module to form a closed loop of the self-test function. The control module will also output a control signal to pin 1 of the NAND gate module. Pin 1 is normally high. When the control module needs to shut down the motor drive signal by itself, pin 1 is pulled low, and the NAND gate module outputs a high level, causing the drive module to stop working.

[0093] The NAND gate module mainly includes a NAND gate circuit. When one of the two input pins is at a low level, the NAND gate output is at a high level.

[0094] The drive module mainly includes a chip composed of Darlington transistors. When the enable control pin EN is at a low level, the drive module works normally and the drive signal PWM is output normally; when EN is at a high level, the drive module stops working and the PWM signal stops outputting.

[0095] During normal self-test:

[0096] The control module outputs a DC high-level HI signal to the Q2 transistor of the self-test trigger module, Q2 is turned on, and Q1 is turned on. The control module also outputs a DC high-level LO signal to the Q3 transistor of the self-test trigger module, and Q3 is turned on. After Q1, Q2, and Q3 are turned on, the two resistors R2 and R3 divide the VCC voltage.

[0097] The level signal of the self-test voltage formed after voltage division is input into comparator 1 and comparator 2. Two resistors are designed in advance so that the voltage value after voltage division is less than the preset low voltage reference signal (REFL) to simulate the self-test under abnormal conditions.

[0098] Comparator 1 compares the received self-test voltage with the preset high voltage reference signal (REFH). If the self-test voltage is less than REFH, a high level result is output. The self-test current (and sampling current) is input to the inverting terminal of comparator 1, while the high voltage reference signal REFH is connected to its inverting terminal. The sampling current connected to the inverting terminal means that if the current is too large, the voltage at the inverting terminal will be higher, which will cause the output of the comparator to be low, indicating that the current exceeds the upper threshold. The inverting terminal is connected to REFH, which sets a high current threshold (upper limit). When the sampling current exceeds this upper limit, the comparator output will change, triggering overcurrent protection.

[0099] Comparator 2 compares the received self-test voltage with the preset low voltage reference signal (REFL). If the self-test voltage is less than REFL, a low level result is output. The self-test current (and sampling current) is input to its in-phase terminal, while its inverting terminal is connected to the low voltage reference signal REFL. Connecting the sampling current to the same phase means that if the current is small, the output of the comparator is high; if the current is too low, the output will be low, indicating that the current is lower than the lower threshold. The inverting terminal REFL sets a low current threshold (lower limit). When the sampling current is lower than this lower limit, the output of the comparator will also change, triggering the protection mechanism.

[0100] If the comparator 1 is at a high level and the comparator 2 is at a low level, the comparator module outputs a low level comparison result to the control module.

[0101] When the control module receives a low level, it determines that the overcurrent protection circuit can work normally.

[0102] In another self-test, the self-test voltage set by the resistor voltage divider can also be higher than REFH, so that comparator 1 outputs a low level, comparator 2 outputs a high level, and the final comparison result is still a low level. When the control module receives the low level comparison result, it can determine that the overcurrent protection circuit is working normally.

[0103] During self-test, there is no sampling current input and the drive module does not work.

[0104] When the self-test is abnormal:

[0105] That is, both comparator 1 and comparator 2 output high level, and the control module receives the high level comparison result, then determines that the overcurrent protection circuit is abnormal, and the comparator cannot execute the protection strategy normally. The control module outputs the abnormal signal of the overcurrent protection circuit to other modules of the vehicle, such as the display module, or the vehicle ECU, etc.

[0106] When the self-test is finished and the overcurrent protection circuit is working normally:

[0107] like Figure 4 As shown, the sampling current is input into the comparator module, and comparator 1 and comparator 2 compare the voltage or current to obtain the sampling comparison result. Under normal circumstances, the voltage of the sampling current is within the range of REFL-REFH. In this way, both comparator 1 and comparator 2 output a high level, and the high level signal is output to the control module on the one hand, and the high level signal is output to pin 2 of the NAND gate module on the other hand. Pin 1 of the NAND gate is connected to the control module, and the control module outputs a high level to pin 1.

[0108] The NAND gate module outputs a low-level signal to the EN pin of the driver module when both pin 1 and pin 2 are high. When the EN pin is low, the driver module works normally and the drive signal PWM is output normally.

[0109] When the overcurrent protection function is activated:

[0110] When the peak value of the sampling current is too high, comparator 1 outputs a low level, comparator 2 outputs a high level, and the overall output is a low level to pin 2 of the NAND gate module. For the NAND gate module, pin 1 is a high level, pin 2 is a low level, and a high level is output to the EN pin of the driver module. When EN is a high level, the driver module stops working, the PWM signal stops outputting, and the protection function is turned on.

[0111] When the peak value of the sampling current is too low, comparator 1 outputs a high level, comparator 2 outputs a low level, and the overall output is a low level to pin 2 of the NAND gate module. For the NAND gate module, pin 1 is a high level, pin 2 is a low level, and a high level is output to the EN pin of the driver module. When EN is a high level, the driver module stops working, the PWM signal stops outputting, and the protection function is turned on.

[0112] Through the method of this example, the self-check of the overcurrent protection circuit can be realized to ensure that the overcurrent protection circuit can normally perform the protection function. The overcurrent protection detection is performed after receiving the sampled current.

[0113] Currently, the self-test mode is triggered by the control module sending HI and LO signals. Different self-test modes can be expanded, such as cyclic self-test (automatically triggering a self-test at regular intervals or cycles), or on-demand self-test (triggered by circuit status or external signals). This can improve the system's self-diagnosis capabilities and ensure that the system can perform regular self-tests under different working conditions.

[0114] In addition, if the system's working environment changes greatly (such as temperature changes or load fluctuations), an adaptive reference voltage adjustment mechanism can be added. The control module can dynamically adjust the reference voltage according to the actual sampling signal changes, thereby maintaining the system's accurate detection and protection of current.

[0115] REHL and REFH are the thresholds for current detection as reference voltages. You can consider using a high-precision reference voltage source to further improve the accuracy of the system. For example, you can use a bandgap reference voltage source to provide a more stable reference voltage and reduce errors caused by temperature fluctuations or power supply fluctuations.

[0116] In the above example, the comparator module triggers an exception when the current exceeds the threshold through two comparators. Redundant design can be further considered, that is, adding additional comparators and adopting a voting mechanism to reduce misjudgment caused by single-point failures. Redundant design can improve the reliability of the system.

[0117] Based on the above example, a fault alarm mechanism can also be designed in the circuit. When the sampling current exceeds the normal range, it not only triggers the NAND gate to output a high level and stop the motor drive, but also adds physical alarm means such as sound alarm (buzzer) or LED indicator to prompt the user in real time that the circuit is abnormal. During self-test, the sound alarm is not triggered.

[0118] Figure 5 The structural diagram of the control module provided in this application is as follows: Figure 5 As shown, the control module provided in this embodiment includes:

[0119] A first output unit, used for outputting a self-test signal to a self-test trigger module when entering a self-test mode;

[0120] A second output unit, used for outputting a high level signal to a first pin of the NAND gate module;

[0121] A third output unit, used for outputting a PWM modulation signal to a driving module;

[0122] A fourth output unit, used for outputting the state of the overcurrent protection circuit;

[0123] The receiving unit is used to receive the comparison result sent by the comparator module.

[0124] The control module provided in this embodiment can execute the method implemented by the above control module, and its implementation principle and technical effect are similar, so this embodiment will not be described in detail here.

[0125] Figure 6 This is a schematic diagram of the structure of the electronic device provided in this application, which may be a hardware device of the control module. Figure 6 As shown, the electronic device 50 provided in this embodiment includes: at least one processor 501 and a memory 502. Optionally, the device 50 also includes a communication component 503. The processor 501, the memory 502 and the communication component 503 are connected via a bus 504.

[0126] In a specific implementation process, at least one processor 501 executes the computer-executable instructions stored in the memory 502, so that at least one processor 501 executes the above method.

[0127] The specific implementation process of the processor 501 can be found in the above method embodiment, and its implementation principle and technical effect are similar, so this embodiment will not be repeated here.

[0128] In the above embodiments, it should be understood that the processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), etc. A general-purpose processor may be a microprocessor or any conventional processor. The steps of the method disclosed in the invention may be directly implemented as being executed by a hardware processor, or may be executed by a combination of hardware and software modules in the processor.

[0129] The memory may include a high-speed memory (Random Access Memory, RAM), and may also include a non-volatile memory (Non-volatile Memory, NVM), such as at least one disk memory.

[0130] The bus may be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. The bus may be divided into an address bus, a data bus, a control bus, etc. For ease of representation, the bus in the drawings of the present application is not limited to only one bus or one type of bus.

[0131] The present application also provides a computer program product, including a computer program, which implements the above method when executed by a processor.

[0132] The present application also provides a computer-readable storage medium, in which computer-executable instructions are stored. When a processor executes the computer-executable instructions, the above method is implemented.

[0133] The above-mentioned readable storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, magnetic disk or optical disk. The readable storage medium can be any available medium that can be accessed by a general or special-purpose computer.

[0134] An exemplary readable storage medium is coupled to a processor so that the processor can read information from the readable storage medium and write information to the readable storage medium. Of course, the readable storage medium can also be a component of the processor. The processor and the readable storage medium can be located in an application specific integrated circuit (Application Specific Integrated Circuits, referred to as: ASIC). Of course, the processor and the readable storage medium can also exist in the device as discrete components.

[0135] The division of units is only a logical function division, and there may be other divisions in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interface, device or unit, which can be electrical, mechanical or other forms.

[0136] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0137] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0138] If the function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods of each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc. Various media that can store program codes.

[0139] Those skilled in the art can understand that all or part of the steps of implementing the above-mentioned method embodiments can be completed by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When the program is executed, the steps of the above-mentioned method embodiments are executed; and the aforementioned storage medium includes: ROM, RAM, disk or optical disk and other media that can store program codes.

[0140] Finally, it should be noted that those skilled in the art will readily conceive of other embodiments of the present invention after considering the specification and practicing the invention disclosed herein. The present invention is intended to cover any variations, uses or adaptations of the present invention, which follow the general principles of the present invention and include common knowledge or customary technical means in the art not disclosed by the present invention, are not limited to the precise structure described above and shown in the drawings, and may be modified and changed in various ways without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

Claims

1. A self-checking circuit for overcurrent protection, characterized in that: include: Self-check trigger module, comparator module, control module, NAND gate module and drive module; The signal input end of the self-test trigger module is connected to the first output end of the control module, the output end of the self-test trigger module is connected to the input end of the comparator module, and the self-test trigger module is used to input the self-test voltage in the circuit to the comparator module when receiving the self-test signal of the control module; The output end of the comparator module is connected to the input end of the control module, and the comparator module is used to compare the input self-test voltage with a preset voltage range; The first input end of the NAND gate module is connected to the second output end of the control module, and the second input end of the NAND gate module is connected to the output end of the comparator module; The output end of the NAND gate module is connected to the input end of the driving module.

2. The self-test circuit according to claim 1, characterized in that: The comparator module includes a first comparator and a second comparator; The first comparator is used to compare the input self-test voltage with the upper limit of the voltage range; The second comparator is used to compare the input self-test voltage with the lower limit of the voltage range.

3. The self-test circuit according to claim 1 or 2, characterized in that: The self-test trigger module includes a self-test switch and a voltage-dividing resistor; When the self-test signal is received, the self-test switch is turned on, and the self-test voltage formed by dividing the power supply voltage VCC by the voltage-dividing resistor is output to the comparator module.

4. The self-test circuit according to claim 3, characterized in that: The self-test switch comprises a high-side switch and a low-side switch; The high side switch comprises a first transistor and a second transistor; The low side switch comprises a third transistor; When the high-side switch and the low-side switch are both turned on, the self-test switch is turned on.

5. A self-checking method for overcurrent protection, characterized in that: The self-checking circuit for overcurrent protection according to any one of claims 1 to 4, the method comprising: When the control module enters the self-test mode, it outputs a self-test signal to the self-test trigger module; The self-test trigger module receives the self-test signal and outputs a self-test voltage to the comparator module; The comparator module compares the self-test voltage with a preset voltage range to obtain a comparison result; The comparator module sends the comparison result to the control module; The control module determines a state of the overcurrent protection circuit according to the comparison result, and the state includes a normal state or an abnormal state.

6. The self-test method according to claim 5, characterized in that: If the self-test trigger module includes: a first transistor and a high-side switch composed of the first transistor, a low-side switch composed of a third transistor, and a resistor, and the self-test signal includes a high-level HI signal and a high-level LO signal, then the control module outputs the self-test signal to the self-test trigger module, including: The control module outputs a high-level HI signal to the high-side switch to turn on the high-side switch; The control module outputs a high-level LO signal to the low-side switch to turn on the low-side switch.

7. The self-test method according to claim 5, characterized in that: If the comparator module includes a first comparator and a second comparator, the comparator module compares the self-test voltage with a preset voltage range to obtain a comparison result, including: The first comparator compares the self-test voltage with an upper limit of a preset voltage range; If the self-test voltage is greater than the upper limit of the voltage range, outputting a first result of a low level; If the self-test voltage is less than or equal to the upper limit of the voltage range, outputting a first result of a high level; The second comparator compares the self-test voltage with a lower limit of a preset voltage range; If the self-test voltage is less than the lower limit of the voltage range, outputting a second result of a low level; If the self-test voltage is greater than or equal to the lower limit of the voltage range, outputting a second result of a high level; The comparison result is determined according to the first result and the second result.

8. The self-test method according to claim 7, characterized in that: The determining the comparison result according to the first result and the second result includes: If any one of the first result and the second result is a low level, the comparison result is a low level; otherwise, the comparison result is a high level.

9. The self-test method according to claim 7 or 8, characterized in that: If the pre-designed self-test voltage is less than the lower limit of the voltage range, or greater than the upper limit of the voltage range, the control module determines the state of the overcurrent protection circuit according to the comparison result, including: If the comparison result is a low level, the control module determines that the overcurrent protection circuit is in a normal state; If the comparison result is a high level, the control module determines that the overcurrent protection circuit is in an abnormal state.

10. The self-test method according to any one of claims 5 to 8, characterized in that: The method further comprises: When the control module exits the self-test mode, it stops outputting the self-test signal and outputs a high-level signal to the first input terminal of the NAND gate module; The comparator module receives a sampled current, compares a voltage of the sampled current with the voltage range, and obtains a sampled comparison result, wherein the sampled comparison result is used to indicate a high level or a low level; Outputting the sampling comparison result to the second input terminal of the NAND gate module; If either the first output terminal or the second input terminal of the NAND gate module is at a low level, the NAND gate module outputs a high level to the driving module to control the driving module to stop working.

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