Safe MOSFET circuit and control method

Abstract

The invention relates to a safe MOSFET circuit and a control method, the safe MOSFET circuit comprises a power supply module, a safe power control module, an airbag ignition module, a detection module and an MCU control module, the short circuit detection signal input end of the detection module is movably connected with the power supply output end of the safe power control module, and the short circuit detection signal input end of the detection module is movably connected with the power supply output end of the airbag ignition module. The open circuit detection signal output end of the detection module is connected with the signal input end of the safety power control module so as to adjust the voltage output by the safety power control module, and then short circuit or open circuit detection of a corresponding MOS tube in the safety power control module can be carried out. The detection module is connected with the safety power control module through a short circuit and open circuit detection signal input end, abnormal conditions in the circuit can be detected and responded in time, a redundancy control and detection mechanism is added, the risk of a single fault point is effectively reduced, the endurance capacity of the circuit to a high voltage condition is enhanced, and the service life of the circuit is prolonged. And the stable operation of the safety air bag system at the critical moment is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of safety MOSFET circuits and control methods, and in particular to a safety MOSFET circuit and a control method. Background Art

[0002] At present, the traditional MOSFET circuit lacks sufficient safety redundancy in the architecture of the automotive airbag system, which means that in applications with high reliability requirements, such as airbag control, the failure of a single device may lead to serious consequences. Usually, these circuits rely on microcontrollers (MCUs) or ignition chips to control the switching of MOSFETs, but if these control units fail, the MOSFET will not work properly, which will affect the power supply of the ignition module and cause the risk of a single point of failure; at the same time, the traditional MOSFET circuit has limitations in the withstand voltage level. When the airbag system is working, it may encounter high voltage. If the withstand voltage level of the MOSFET circuit is insufficient, the ignition chip will break down due to the high voltage, which will lead to the misfire of the airbag; in summary, the lack of sufficient safety redundancy and insufficient withstand voltage level will cause the airbag system to fail to work properly at critical moments, increase the risk of failure, and thus endanger the safety of passengers. Summary of the invention

[0003] In order to solve the problem that traditional MOSFET circuits lack sufficient safety redundancy and insufficient voltage resistance level, which causes the airbag system to fail to work normally at critical moments, increases the risk of failure, and thus endangers the safety of passengers, the present application provides a safety MOSFET circuit and control method.

[0004] The above-mentioned invention objective of the present application is achieved through the following technical solutions: A safety MOSFET circuit comprises a power supply module, a safety power control module, an airbag ignition module, a detection module and an MCU control module, wherein the power output end of the power supply module is connected to the power input end of the safety power control module, the power output end of the safety power control module is connected to the power input end of the airbag ignition module, the power signal input end of the MCU control module is connected to the power signal output end of the airbag ignition module, the signal output end of the MCU control module is connected to the signal input end of the detection module, the short-circuit detection signal input end of the detection module is movably connected to the power output end of the safety power control module, so as to adjust the voltage output by the safety power control module and then perform short-circuit detection of the corresponding MOS tube in the safety power control module, and the open-circuit detection signal output end of the detection module is connected to the signal input end of the safety power control module, so as to adjust the voltage output by the safety power control module and then perform open-circuit detection of the corresponding MOS tube in the safety power control module.

[0005] By adopting the above technical solution, the present application realizes multiple protection and control of the airbag ignition system by integrating the power supply module, the safety power control module, the airbag ignition module, the detection module and the MCU control module. The MCU control module is connected to the detection module through the signal output terminal to realize real-time monitoring of the circuit status, while the detection module is connected to the safety power control module through the short circuit and open circuit detection signal input terminal, which can timely detect and respond to abnormal conditions in the circuit, such as short circuit or open circuit of the MOS tube, and protect the circuit by adjusting the voltage output by the safety power control module, thereby improving the reliability and safety of the entire airbag ignition system; this design effectively reduces the risk of a single fault point by adding redundant control and detection mechanisms, and enhances the circuit's tolerance to high voltage conditions, ensuring the stable operation of the airbag system at critical moments.

[0006] Preferably, the safety power control module includes a MOS tube element, a resistor element and a diode element, the positive terminal of the diode element is connected to the power output terminal of the power supply module, the negative terminal of the diode element is respectively connected to the first end of the resistor element and the first conduction end of the MOS tube element, the common node between the second end of the resistor element and the second conduction end of the MOS tube element serves as the power output terminal of the safety power control module to be connected to the power input terminal of the airbag ignition module, the negative terminal of the diode element is connected to the power input terminal of the airbag ignition module, and the controlled end of the MOS tube element is connected to the short-circuit detection signal input terminal of the detection module.

[0007] By adopting the above technical solution, the safety power control module realizes the voltage stabilization control and short circuit detection functions of the power supply output by integrating MOS tubes, resistors and diode components, effectively improving the safety and stability of the airbag ignition system.

[0008] Preferably, the detection module includes a short-circuit detection unit and a circuit break detection unit, the power input end of the short-circuit detection unit serves as the short-circuit detection signal input end of the detection module, the signal input end of the short-circuit detection unit is connected to the short-circuit detection control signal output end of the MCU control module, so as to control the active connection between the power input end of the short-circuit detection unit and the power output end of the safety power control module, the signal input end of the circuit break detection unit is connected to the circuit break detection control signal output end of the MCU control module, and the signal output end of the circuit break detection unit serves as the circuit break detection signal output end of the detection module, and is connected to the signal input end of the safety power control module.

[0009] By adopting the above technical solution, the detection module realizes real-time monitoring and fault diagnosis of the output of the safety power control module through the coordinated work of the short-circuit detection unit and the open-circuit detection unit, combined with the precise regulation of the MCU control module, thereby enhancing the self-protection and fault-tolerance capabilities of the circuit.

[0010] Preferably, the short circuit detection unit includes a transistor Q7, a resistor R14, a resistor R15 and a resistor R16, the second end of the resistor element is connected to the first end of the resistor R14, and the common node between the second end of the resistor element and the first end of the resistor R14 is connected to the power input end of the airbag ignition module, the second end of the resistor R14 is connected to the first conduction end of the transistor Q7, the second conduction end of the transistor Q7 is grounded, the controlled end of the transistor Q7 is connected to the first end of the resistor R15, the second end of the resistor R15 is connected to the first end of the resistor R16, the second end of the resistor R16 is grounded, and the common node between the second end of the resistor R15 and the first end of the resistor R16 is connected to the short circuit detection control signal output end of the MCU control module.

[0011] By adopting the above technical solution, the short-circuit detection unit monitors the output of the safety power control module under the control of the MCU through the combination of transistor Q7, resistors R14, R15 and R16, and can detect the short-circuit situation in time, thereby providing rapid response and protection to ensure the reliability of the airbag ignition system.

[0012] Preferably, the circuit break detection unit includes the transistor Q6-A, the transistor Q6-B, the resistor R18, the resistor R17 and the diode D9, the controlled end of the transistor Q6-A is connected to the circuit break detection control signal output end of the MCU control module, the first conducting end of the transistor Q6-A is grounded, the second conducting end of the transistor Q6-A is connected to the controlled end of the transistor Q6-B, the first conducting end of the transistor Q6-B is connected to the first end of the resistor R17, the second end of the resistor R17 is grounded, the common node between the first conducting end of the transistor Q6-B and the first end of the resistor R17 is connected to the ignition preparation drive port of the airbag ignition module, the second conducting end of the transistor Q6-B is connected to the positive end of the diode D9, and the negative end of the diode D9 is connected to the controlled end of the MOS tube element.

[0013] By adopting the above technical solution, the circuit break detection unit utilizes the configuration of transistors Q6-A, Q6-B, resistors R18, R17 and diode D9, and under the regulation of the circuit break detection control signal output end of the MCU, can effectively monitor and respond to the ignition preparation state of the airbag ignition module, and work in conjunction with the MOS tube element to enhance the detection of circuit breaks and the maintenance of system stability.

[0014] Preferably, the detection module includes a control management chip Q12, a resistor R23, a resistor R24, a resistor R26 and a resistor R27. The control management chip Q12 is provided with a transistor Q12-A and a transistor Q12-B. The first end of the resistor R27 is connected to the controlled end of the transistor Q12-B, the second end of the resistor R27 is connected to the short-circuit detection control signal output end of the MCU control module, the first conduction end of the transistor Q12-B is connected to the first end of the resistor R26, and the resistor R26 The second end of the transistor Q12-B is connected to the power output end of the safety power control module, the first end of the resistor R24 ​​of the circuit breaker detection control signal output end of the MCU control module is connected, the second end of R24 is connected to the controlled end of the transistor Q12-A, the first conduction end of the transistor Q12-A is connected to the controlled end of the MOS tube element, the second conduction end of the transistor Q12-A is connected to the first end of the resistor R23, and the second end of the resistor R23 is grounded.

[0015] By adopting the above technical solution, the detection module realizes accurate detection and control of short circuit and open circuit of the power output of the safety power control module and the controlled end of the MOS tube element through the coordinated action of the control management chip Q12, resistors R23, R24, R26 and R27, thereby improving the self-monitoring and protection capabilities of the circuit.

[0016] A control method for a safety MOSFET circuit is applied to a safety MOSFET circuit, comprising the following steps: Acquire a first power supply voltage parameter of an airbag ignition module; Controlling the detection module to perform short circuit detection and obtain corresponding second supply voltage parameters; Comparing the first supply voltage parameter with the second supply voltage parameter to generate a corresponding short-circuit state evaluation parameter, wherein the short-circuit state evaluation parameter is used to generate a corresponding alarm instruction; Determine whether the detection module performs open circuit detection according to the short circuit state evaluation parameter, and if it is determined to perform open circuit detection, obtain the corresponding third power supply voltage parameter; The second supply voltage parameter and the third supply voltage parameter are compared to generate a corresponding disconnection state evaluation parameter, wherein the disconnection state evaluation parameter is used to generate a corresponding alarm instruction.

[0017] By adopting the above technical solution, the control method of the safety MOSFET circuit achieves accurate evaluation and alarm of short circuit and open circuit conditions by acquiring and comparing power supply voltage parameters and generating evaluation parameters, thereby effectively improving the fault detection and protection capabilities of the circuit.

[0018] Preferably, the step of obtaining the first power supply voltage parameter of the airbag ignition module includes: Get the power supply voltage VER of the power supply module and the total voltage drop V of the first circuit drop1 , where the total voltage drop of the first circuit V drop1 When the parameter is less than the preset zero parameter, the total pressure drop V drop1 Assign a value of 0; According to the power supply voltage VER and the first loop total voltage drop V drop1 , determine the corresponding first supply voltage parameter V SSXY1 , where V SSXY1 =VER-V drop1 .

[0019] By adopting the above technical solution, in the step of obtaining the first power supply voltage parameter of the airbag ignition module, by calculating the power supply voltage VER and the total voltage drop of the first circuit (if it is less than the preset zero parameter, it is assigned to 0), the actual power supply voltage of the airbag ignition module can be accurately determined, providing a reliable reference for subsequent short circuit and open circuit detection.

[0020] Preferably, in the step of obtaining the corresponding second supply voltage parameter, the detection module includes a short circuit detection unit, and the short circuit detection unit is a discharge circuit for voltage division, and further includes the following steps: Get the voltage division ratio K and the total voltage drop V of the second circuit drop2 ; According to the voltage division ratio K and the total voltage drop V of the second circuit drop2 , determine the corresponding second supply voltage parameter V SSXY2 , where V SSXY2 =K×V drop2 ; In the step of obtaining the corresponding third power supply voltage parameter, the detection module includes a circuit break detection unit, and the circuit break detection unit is used to drive the corresponding MOS tube in the safety power control module to be turned on and in the linear region, and also includes the following steps: obtaining the ignition preparation drive voltage VSF of the airbag ignition module, the gate-source threshold voltage V gsth , and the total voltage drop of the third circuit V drop3 ; According to the gate-source threshold voltage V gsth , and the total voltage drop of the third circuit V drop3 , determine the corresponding third supply voltage parameter V SSXY3 , where V SSXY3 =VSF-V drop3 -V gsth .

[0021] By adopting the above technical solution, in the step of obtaining the second power supply voltage parameter, the voltage division ratio and the total voltage drop of the second circuit are obtained through the voltage division discharge circuit of the short circuit detection unit, and the second power supply voltage parameter is calculated; in the step of obtaining the third power supply voltage parameter, the MOS tube is driven to conduct and the relevant voltage and the total voltage drop of the third circuit are obtained through the open circuit detection unit, and the third power supply voltage parameter is calculated. These steps ensure the accurate acquisition of the voltage parameters required for the accurate evaluation of the short circuit and open circuit states, thereby improving the fault detection effect and control accuracy of the safety MOSFET circuit.

[0022] Preferably, in the step of obtaining the corresponding second supply voltage parameter, the detection module includes a short circuit detection unit, and the short circuit detection unit is a discharge circuit for voltage division, and further includes the following steps: Obtaining the current IC in the discharge loop, the total resistance value R in the safety power control module, and other diode voltage drops VG; Determine the total voltage drop V of the second circuit according to the current IC, the total resistance value R and other diode voltage drops VG. drop2 , where V drop2 =(IC×R)+VG; According to the total voltage drop V of the second circuit drop2 , and the supply voltage VER, determine the corresponding second supply voltage parameter V SSXY2 , where V SSXY2 =VER-V drop2 .

[0023] By adopting the above technical solution, preferably, in the step of obtaining the second supply voltage parameters, the total voltage drop of the second circuit is calculated by measuring the current IC, the total resistance value R and other diode voltage drops VG in the short-circuit detection unit (discharge circuit), and the second supply voltage parameters are determined in combination with the power supply voltage VER, thereby achieving accurate evaluation and alarm of the short-circuit state and enhancing the fault detection and protection performance of the safety MOSFET circuit.

[0024] In summary, the present application includes at least one of the following beneficial technical effects: 1. This application integrates a power supply module, a safety power control module, an airbag ignition module, a detection module and an MCU control module, and the design realizes multiple protections and controls for the airbag ignition system. The MCU control module is connected to the detection module through the signal output terminal to realize real-time monitoring of the circuit status, while the detection module is connected to the safety power control module through the short circuit and open circuit detection signal input terminal, and can timely detect and respond to abnormal conditions in the circuit, such as short circuit or open circuit of the MOS tube, and protect the circuit by adjusting the voltage output by the safety power control module, thereby improving the reliability and safety of the entire airbag ignition system; this design effectively reduces the risk of a single point of failure by adding redundant control and detection mechanisms, and enhances the circuit's tolerance to high voltage conditions, ensuring the stable operation of the airbag system at critical moments. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a flow chart of a safety MOSFET circuit in an embodiment of the present application.

[0026] Figure 2 It is a partial circuit diagram of a safety MOSFET circuit in Example 1 of the present application; Figure 3 It is a partial circuit diagram of a safety MOSFET circuit in Example 2 of the present application; Figure 4 This is a flow chart of an implementation of a safety MOSFET control method in an embodiment of the present application. DETAILED DESCRIPTION

[0027] The present application is further described in detail below in conjunction with the accompanying drawings.

[0028] In one embodiment, if Figure 1As shown, the present application discloses a safety MOSFET circuit, including a power supply module, a safety power control module, an airbag ignition module, a detection module and an MCU control module, wherein the power output end of the power supply module is connected to the power input end of the safety power control module, the power output end of the safety power control module is connected to the power input end of the airbag ignition module, the power signal input end of the MCU control module is connected to the power signal output end of the airbag ignition module, the signal output end of the MCU control module is connected to the signal input end of the detection module, the short-circuit detection signal input end of the detection module is movably connected to the power output end of the safety power control module, so as to adjust the voltage output by the safety power control module, thereby performing short-circuit detection of the corresponding MOS tube in the safety power control module, and the open-circuit detection signal output end of the detection module is connected to the signal input end of the safety power control module, so as to adjust the voltage output by the safety power control module, thereby performing open-circuit detection of the corresponding MOS tube in the safety power control module.

[0029] In this embodiment, the safety MOSFET circuit is composed of five key modules, which work together to ensure the safe operation of the circuit. The power supply module provides a stable power output for the entire system, and realizes the supply of the voltage required by the circuit through the connection with the safety power control module. The safety power control module is the core of the circuit, which uses components such as MOS tubes, resistors and diodes to accurately control and protect the power. As an important part of the airbag system, the airbag ignition module receives power from the safety power control module and triggers the airbag to deploy under specific conditions. The detection module is responsible for real-time monitoring of the circuit status, including evaluating the integrity of the circuit through short circuit and open circuit detection. As the center of the circuit, the MCU control module receives the power signal of the airbag ignition module and sends control instructions to the detection module to coordinate the operation of the entire circuit and provide intelligent protection functions. The mutual cooperation of these modules enables the circuit to achieve efficient energy transmission, reliable power control and timely fault detection, thereby providing strong protection for high-reliability applications such as airbags.

[0030] In summary, this application realizes multiple protections and controls for the airbag ignition system by integrating the power supply module, the safety power control module, the airbag ignition module, the detection module and the MCU control module. The MCU control module is connected to the detection module through the signal output terminal to realize real-time monitoring of the circuit status, while the detection module is connected to the safety power control module through the short circuit and open circuit detection signal input terminal, which can timely detect and respond to abnormal conditions in the circuit, such as short circuit or open circuit of the MOS tube, and protect the circuit by adjusting the voltage output by the safety power control module, thereby improving the reliability and safety of the entire airbag ignition system; this design effectively reduces the risk of a single point of failure by adding redundant control and detection mechanisms, and enhances the circuit's tolerance to high voltage conditions, ensuring the stable operation of the airbag system at critical moments.

[0031] Further, such as Figure 2-3 As shown, the safety power control module includes a MOS tube element, a resistor element and a diode element, the positive terminal of the diode element is connected to the power output terminal of the power supply module, the negative terminal of the diode element is respectively connected to the first end of the resistor element and the first conduction end of the MOS tube element, the common node between the second end of the resistor element and the second conduction end of the MOS tube element serves as the power output terminal of the safety power control module to be connected to the power input terminal of the airbag ignition module, the negative terminal of the diode element is connected to, the connected to the power input terminal of the airbag ignition module, and the controlled end of the MOS tube element is connected to the short-circuit detection signal input terminal of the detection module.

[0032] In this embodiment, the safety power control module is a key component of the entire safety MOSFET circuit. It is composed of a MOS tube element, a resistor element and a diode element, which play an important role together. First, the diode element is used as a rectifier, and its positive terminal is connected to the power output terminal of the power supply module, and the negative terminal is connected to the first end of the resistor element and the first conduction end of the MOS tube element at the same time. This connection method ensures the unidirectional flow of current and provides the necessary voltage drop. Secondly, the resistor element plays the role of voltage division and current limiting in the circuit. It is connected between the negative terminal of the diode element and the second conduction end of the MOS tube element, and helps control the conduction state and power output of the MOS tube through the voltage drop and current limitation on it. The MOS tube element is used as a power switch, and its controlled end is connected to the short-circuit detection signal input end of the detection module. By controlling the conduction and shutdown of the MOS tube, the safety power control module can adjust the power supply voltage and current output to the airbag ignition module. At the same time, the controlled end of the MOS tube is connected to the detection module, so that the module can monitor the working state of the MOS tube, detect the short circuit in time and take corresponding protective measures. The safety power control module achieves precise control and monitoring of the power in the circuit through the coordinated work of MOS tube elements, resistor elements and diode elements. It can not only adjust the output voltage and current, but also detect short-circuit faults in time, thereby improving the safety and reliability of the entire safety MOSFET circuit.

[0033] In summary, the safety power control module realizes the voltage regulation control and short circuit detection functions of the power supply output by integrating MOS tubes, resistors and diode components, effectively improving the safety and stability of the airbag ignition system.

[0034] Embodiment 1: Further, such as Figure 2 As shown, the detection module includes a short-circuit detection unit and a circuit-break detection unit. The power input end of the short-circuit detection unit serves as the short-circuit detection signal input end of the detection module. The signal input end of the short-circuit detection unit is connected to the short-circuit detection control signal output end of the MCU control module to control the active connection between the power input end of the short-circuit detection unit and the power output end of the safety power control module. The signal input end of the circuit-break detection unit is connected to the circuit-break detection control signal output end of the MCU control module. The signal output end of the circuit-break detection unit serves as the circuit-break detection signal output end of the detection module and is connected to the signal input end of the safety power control module.

[0035] In this embodiment, the detection module is a key part responsible for monitoring and fault detection in the safety MOSFET circuit, and is composed of a short circuit detection unit and an open circuit detection unit.

[0036] The short-circuit detection unit receives the short-circuit detection signal from the detection module through its power input terminal and is connected to the short-circuit detection control signal output terminal of the MCU control module. The MCU control module sends a control signal as needed to establish a connection between the power input terminal of the short-circuit detection unit and the power output terminal of the safety power control module. The function of the short-circuit detection unit is to monitor the current and voltage in the circuit. If an abnormal low-resistance current path (short circuit) is detected, it will send a corresponding signal to the MCU control module to indicate that a short-circuit fault may exist.

[0037] The signal input end of the circuit break detection unit is also connected to the circuit break detection control signal output end of the MCU control module, and its signal output end is connected to the signal input end of the safety power control module as the circuit break detection signal output end of the detection module. The function of the circuit break detection unit is to monitor the current and voltage in the circuit. If it detects that the current path is interrupted or the resistance increases abnormally (circuit break), it will send a corresponding signal to the MCU control module to indicate that there may be a circuit break fault.

[0038] The working principle of both units is to determine whether the circuit is working properly by monitoring the changes in current and voltage. When a short circuit or open circuit occurs, the current and voltage will deviate from the normal range and be captured by the detection unit. The role of these units is to detect faults in the circuit in a timely manner and report to the MCU control module so that appropriate protection measures can be taken, such as cutting off the power supply or issuing an alarm signal.

[0039] The short circuit detection unit and open circuit detection unit in the detection module realize real-time monitoring and fault detection of the circuit through interaction with the MCU control module and the safety power control module. Their role is to improve the reliability and safety of the circuit and ensure timely response and processing when a fault occurs.

[0040] In summary, the detection module realizes real-time monitoring and fault diagnosis of the output of the safety power control module through the coordinated work of the short-circuit detection unit and the open-circuit detection unit, combined with the precise regulation of the MCU control module, thereby enhancing the self-protection and fault-tolerance capabilities of the circuit.

[0041] Further, such as Figure 2As shown, the short-circuit detection unit includes a transistor Q7, a resistor R14, a resistor R15 and a resistor R16, the second end of the resistor element is connected to the first end of the resistor R14, and the common node between the second end of the resistor element and the first end of the resistor R14 is connected to the power input end of the airbag ignition module, the second end of the resistor R14 is connected to the first conduction end of the transistor Q7, the second conduction end of the transistor Q7 is grounded, the controlled end of the transistor Q7 is connected to the first end of the resistor R15, the second end of the resistor R15 is connected to the first end of the resistor R16, the second end of the resistor R16 is grounded, and the common node between the second end of the resistor R15 and the first end of the resistor R16 is connected to the short-circuit detection control signal output end of the MCU control module.

[0042] In this embodiment, the short circuit detection unit is a part of the detection module, which is responsible for monitoring the short circuit in the circuit. It is composed of transistor Q7, resistor R14, resistor R15 and resistor R16, and plays a role by interacting with the MCU control module and the safety power control module.

[0043] The working principle of this unit is as follows: Resistor R14 is connected to the power output terminal of the safety power control module, and its other end is connected to the first conduction terminal of the transistor Q7. When the circuit is working normally, the current will flow to the ground through R14 and Q7. Resistors R15 and R16 form a voltage divider circuit, in which one end of R15 is connected to the controlled end of Q7, and the other end is connected to the short-circuit detection control signal output terminal of the MCU control module. The MCU switches Q7 by controlling the high and low levels of this signal.

[0044] When the MCU sends a high-level signal to the controlled end of Q7, Q7 is turned on and current flows to ground through R14, Q7 and R16. If a short circuit occurs in the circuit at this time, the current will increase rapidly, causing the voltage drop on R16 to increase. The MCU determines whether a short circuit has occurred by monitoring the change in this voltage drop. If the voltage drop exceeds the preset threshold, the MCU will identify the short circuit and take appropriate protection measures, such as cutting off the power supply or issuing an alarm signal.

[0045] Therefore, the role of the short-circuit detection unit is to monitor the current and voltage changes in the circuit, detect short-circuit faults in time, and provide feedback information to the MCU control module. It cooperates with resistors R14, R15, R16 and transistor Q7 to achieve accurate detection of short-circuit conditions, thereby improving the safety and reliability of the circuit; R14 is used to divide the voltage to reduce the voltage of VSSXY, so that the system voltage can sense the change value. If there is no change, it means that there is a short circuit. So what can this R14 be named.

[0046] In summary, the short-circuit detection unit monitors the output of the safety power control module under the control of the MCU through the combination of transistor Q7, resistors R14, R15 and R16, and can detect the short-circuit condition in time, thereby providing rapid response and protection to ensure the reliability of the airbag ignition system.

[0047] Further, such as Figure 2 As shown, the circuit break detection unit includes the transistor Q6-A, the transistor Q6-B, the resistor R18, the resistor R17 and the diode D9, the controlled end of the transistor Q6-A is connected to the circuit break detection control signal output end of the MCU control module, the first conduction end of the transistor Q6-A is grounded, the second conduction end of the transistor Q6-A is connected to the controlled end of the transistor Q6-B, the first conduction end of the transistor Q6-B is connected to the first end of the resistor R17, the second end of the resistor R17 is grounded, the common node between the first conduction end of the transistor Q6-B and the first end of the resistor R17 is connected to the ignition preparation drive port of the airbag ignition module, the second conduction end of the transistor Q6-B is connected to the positive end of the diode D9, and the negative end of the diode D9 is connected to the controlled end of the MOS tube element.

[0048] In this embodiment, the circuit breaking detection unit is another important component of the detection module, which is used to monitor the circuit breaking situation in the circuit. It is composed of transistor Q6-A, transistor Q6-B, resistor R18, resistor R17 and diode D9.

[0049] The working principle of this unit is as follows: the controlled end of transistor Q6-A is connected to the circuit break detection control signal output end of the MCU control module. When the MCU sends a control signal, the conduction state of Q6-A will change. The first conduction end of Q6-A is grounded, and the second conduction end is connected to the controlled end of transistor Q6-B. The first conduction end of Q6-B is grounded through resistor R17, and the common node is connected to the ignition preparation drive port of the airbag ignition module. The second conduction end of Q6-B is connected to the positive end of diode D9, and the negative end of diode D9 is connected to the controlled end of the MOS tube element.

[0050] When the airbag ignition module is ready to ignite, it sends a signal to the ignition ready drive port. This signal is transmitted to the diode D9 through the resistor R17 and the transistor Q6-B, and finally reaches the controlled end of the MOS tube element. If there is a short circuit in the circuit, this signal will not reach the MOS tube element, or the arrival time will be delayed.

[0051] The function of the circuit break detection unit is to monitor the transmission process of this signal. If the MCU does not receive the feedback signal from the MOS tube element within the expected time, or the received signal is abnormal, it will determine that there is a circuit break fault in the circuit. The MCU will take corresponding measures based on this judgment, such as issuing an alarm signal or cutting off the power supply, to ensure the safe operation of the system.

[0052] Therefore, the circuit break detection unit detects the circuit break fault in time by monitoring the signal transmission process and provides feedback information to the MCU control module. It cooperates with transistors Q6-A, Q6-B, resistors R17, R18 and diode D9 to achieve effective detection of circuit break conditions, thereby improving the reliability and safety of the circuit.

[0053] In summary, the circuit break detection unit utilizes the configuration of transistors Q6-A, Q6-B, resistors R18, R17 and diode D9. Under the regulation of the circuit break detection control signal output end of the MCU, it can effectively monitor and respond to the ignition preparation status of the airbag ignition module, and work in conjunction with the MOS tube components to enhance the detection of circuit breaks and the maintenance of system stability.

[0054] Embodiment 2: Further, such as Figure 3 As shown, the detection module includes a control management chip Q12, a resistor R23, a resistor R24, a resistor R26 and a resistor R27. The control management chip Q12 is provided with a transistor Q12-A and a transistor Q12-B. The first end of the resistor R27 is connected to the controlled end of the transistor Q12-B, the second end of the resistor R27 is connected to the short-circuit detection control signal output end of the MCU control module, the first conduction end of the transistor Q12-B is connected to the first end of the resistor R26, and the resistor R26 The second end of the transistor Q12-B is connected to the power output end of the safety power control module, the first end of the resistor R24 ​​of the circuit breaker detection control signal output end of the MCU control module is connected, the second end of R24 is connected to the controlled end of the transistor Q12-A, the first conduction end of the transistor Q12-A is connected to the controlled end of the MOS tube element, the second conduction end of the transistor Q12-A is connected to the first end of the resistor R23, and the second end of the resistor R23 is grounded.

[0055] In this embodiment, the detection module monitors and controls the short circuit and open circuit conditions in the safety MOSFET circuit by controlling the combination of the management chip Q12, the resistor R23, the resistor R24, the resistor R26 and the resistor R27.

[0056] The control management chip Q12 has built-in transistors Q12-A and Q12-B for logical control of short circuit and open circuit detection. One end of the resistor R27 is connected to the controlled end of the transistor Q12-B, and the other end is connected to the short circuit detection control signal output end of the MCU control module. When the MCU sends a short circuit detection control signal, the voltage on the resistor R27 will change, thereby affecting the conduction state of Q12-B. The first conduction end of Q12-B is grounded through the resistor R26, and the second conduction end is connected to the power output end of the safety power control module. By monitoring the conduction state of Q12-B, it can be determined whether there is a short circuit.

[0057] On the other hand, one end of the resistor R24 ​​is connected to the output end of the circuit break detection control signal of the MCU control module, and the other end is connected to the controlled end of the transistor Q12-A. The first conduction end of Q12-A is connected to the controlled end of the MOS tube element, and the second conduction end is grounded through the resistor R23. When the MCU sends a circuit break detection control signal, the voltage on the resistor R24 ​​will change, affecting the conduction state of Q12-A. By monitoring the conduction state of Q12-A and the feedback of the MOS tube element, it can be determined whether there is a circuit break.

[0058] The detection module monitors short circuit and open circuit conditions by controlling the state changes of transistors Q12-A and Q12-B in the management chip Q12 and combining the voltage division function of resistors R23, R24, R26 and R27. These modules work together to provide the MCU with accurate fault detection information, so that corresponding protection measures can be taken in time to ensure the safe operation of the circuit.

[0059] In summary, the detection module realizes accurate detection and control of short circuit and open circuit of the power output of the safety power control module and the controlled end of the MOS tube element through the coordinated action of the control management chip Q12, resistors R23, R24, R26 and R27, thereby improving the self-monitoring and protection capabilities of the circuit.

[0060] Preferably, the chip model of the airbag ignition module can be L9680, which is an advanced airbag integrated circuit (IC) produced by STMicroelectronics and is mainly used in mid-to-high-end automobile airbag systems.<web_ec1289f4> It is designed to provide key functions required by airbag systems, including power management, sensor interface and other safety-related functions. According to the searched information, L9680 has the following features: Power Management: The L9680 integrates a boost regulator to provide energy reserve output voltage for the airbag system. The output voltage can be selected by the user as 23V or 33V with an accuracy within ±5%.

[0061] Sensor interface: The chip supports an integrated active wheel speed sensor interface, which facilitates the integration of safety systems.

[0062] System Diagnostics: The L9680 includes diagnostics of the storage capacitor value and ESR (equivalent series resistance) to ensure system integrity and reliability.

[0063] Compatibility: The device is compatible with other airbag ICs in the L9678 and L9679 families, providing flexible design options.

[0064] like Figure 4 As shown, a control method for a safety MOSFET circuit is applied to a safety MOSFET circuit, comprising the following steps: S10, obtaining a first power supply voltage parameter of the airbag ignition module; In this embodiment, in the safety MOSFET circuit, the first power supply voltage parameter refers to the actual operating voltage received by the airbag ignition module from the power supply module, which is used to ensure that the airbag ignition module can obtain sufficient energy to complete its function under normal working conditions.

[0065] Therefore, obtaining the first power supply voltage parameter of the airbag ignition module is an important step to ensure the normal operation and safety of the circuit. By monitoring and comparing the first power supply voltage parameter with other related parameters, potential faults or abnormal conditions can be discovered in time and corresponding protective measures can be taken.

[0066] In summary, the first power supply voltage parameter is the actual operating voltage required for the normal operation of the airbag ignition module, which can be monitored and compared to ensure the reliability and safety of the circuit.

[0067] S20, controlling the detection module to perform short circuit detection and obtain corresponding second supply voltage parameters; In this embodiment, in the safety MOSFET circuit, the second supply voltage parameter refers to a voltage parameter obtained when a short circuit detection is performed by the detection module, which is obtained by monitoring the current and voltage changes in the circuit during the short circuit detection process.

[0068] The acquisition of the second supply voltage parameter usually requires controlling the detection module to enter a short circuit detection mode. In this mode, the detection module monitors the current and voltage changes in the circuit and determines whether there is a short circuit based on these changes. If a short circuit is detected, the second supply voltage parameter will reflect the abnormal voltage condition in the circuit.

[0069] For example, suppose that when performing short circuit detection, the detection module detects that the current in the circuit suddenly increases, and the voltage drop also increases, which may indicate that there is a short circuit. In this case, the second supply voltage parameter may be lower than the normal operating voltage because the increase in current will cause the resistance in the circuit to decrease, thereby reducing the voltage.

[0070] Therefore, obtaining the corresponding second supply voltage parameter is an important step in short-circuit detection. It can determine whether a short circuit exists by monitoring the current and voltage changes in the circuit and take corresponding protective measures in time.

[0071] S30, comparing the first supply voltage parameter and the second supply voltage parameter to generate a corresponding short-circuit state evaluation parameter, wherein the short-circuit state evaluation parameter is used to generate a corresponding alarm instruction; In this embodiment, in the safety MOSFET circuit, the short circuit state evaluation parameter is generated by comparing the first supply voltage parameter and the second supply voltage parameter, and is used to evaluate whether there is a short circuit in the circuit. It is a comparison-based indicator used to determine whether the circuit is in a normal working state.

[0072] When the first supply voltage parameter (normal operating voltage) is compared with the second supply voltage parameter (the voltage obtained during short circuit detection), if the second supply voltage parameter is significantly lower than the first supply voltage parameter, this may indicate that there is a short circuit in the circuit. Based on this comparison result, a short circuit status assessment parameter can be generated to assess the health of the circuit.

[0073] The alarm instruction is generated based on the short circuit status evaluation parameters and is used to alert the system when a short circuit condition is detected. It can take many forms, such as sound and light alarms, SMS notifications, or automatic protection measures. The purpose of the alarm instruction is to alert maintenance personnel or users to potential dangerous situations and take appropriate measures to solve the problem.

[0074] In summary, the short circuit status evaluation parameter is generated by comparing the first supply voltage parameter and the second supply voltage parameter, and is used to evaluate whether there is a short circuit in the circuit. The alarm instruction is generated based on the short circuit status evaluation parameter, and is used to issue an alarm to the system when a short circuit is detected.

[0075] S40, determining whether the detection module performs open circuit detection according to the short circuit state evaluation parameter, and if it is determined to perform open circuit detection, obtaining a corresponding third supply voltage parameter; In this embodiment, in the safety MOSFET circuit, the third supply voltage parameter is obtained after determining to perform a circuit break detection. It is obtained by monitoring the current and voltage changes in the circuit and is used to evaluate whether there is a circuit break in the circuit.

[0076] The acquisition of the third supply voltage parameter usually requires controlling the detection module to enter a circuit break detection mode. In this mode, the detection module monitors the current and voltage changes in the circuit and determines whether there is a circuit break based on these changes. If a circuit break is detected, the third supply voltage parameter will reflect the abnormal voltage condition in the circuit.

[0077] For example, if the detection module detects that the current in the circuit suddenly decreases or disappears, and the voltage drop also increases during the circuit break detection, this may indicate that there is a circuit break. In this case, the third supply voltage parameter may be higher than the normal operating voltage because the reduction in current will increase the resistance in the circuit, thereby increasing the voltage.

[0078] Therefore, obtaining the corresponding third power supply voltage parameter is an important step in circuit break detection, which can determine whether there is a circuit break by monitoring the current and voltage changes in the circuit and take corresponding protective measures in time.

[0079] S50: Compare the second power supply voltage parameter with the third power supply voltage parameter to generate a corresponding circuit breaker status evaluation parameter, wherein the circuit breaker status evaluation parameter is used to generate a corresponding alarm instruction.

[0080] In this embodiment, in the safety MOSFET circuit, the circuit-breaking state evaluation parameter is generated by comparing the second supply voltage parameter and the third supply voltage parameter, and is used to evaluate whether there is a circuit-breaking condition in the circuit. It is a comparison-based indicator used to determine whether the circuit is in a normal working state.

[0081] When the second supply voltage parameter (the voltage obtained during short circuit detection) is compared with the third supply voltage parameter (the voltage obtained during open circuit detection), if the third supply voltage parameter is significantly higher than the second supply voltage parameter, this may indicate that there is an open circuit in the circuit. Based on this comparison result, a circuit break status assessment parameter can be generated to assess the health of the circuit.

[0082] The generation of the circuit-breaking status evaluation parameter helps to timely discover potential problems in the circuit and take appropriate measures to solve the problem. It can determine whether there is a circuit-breaking situation in the circuit by comparing the second supply voltage parameter and the third supply voltage parameter, thereby providing accurate information for maintenance personnel or users to take timely actions to repair the fault or avoid potential dangerous situations.

[0083] In summary, the control method of the safety MOSFET circuit achieves accurate evaluation and alarm of short circuit and open circuit states by acquiring and comparing power supply voltage parameters and generating evaluation parameters, thereby effectively improving the fault detection and protection capabilities of the circuit.

[0084] Further, in S10, that is, the step of obtaining the first power supply voltage parameter of the airbag ignition module, it includes: S101, obtain the power supply voltage VER of the power supply module and the total voltage drop V of the first circuit drop1 , where the total voltage drop of the first circuit V drop1 When the parameter is less than the preset zero parameter, the total pressure drop V drop1 Assign a value of 0; S102: according to the power supply voltage VER and the first loop total voltage drop V drop1 , determine the corresponding first supply voltage parameter V SSXY1 , where V SSXY1 =VER-V drop1 .

[0085] As shown in the figure, after V SSXY1 、V SSXY2 、V SSXY3 In the specific working principle, it is collectively referred to as V SSXY The specific working principle can be explained as follows: VER is the voltage of the energy storage capacitor, SSXY is the power supply voltage of the ignition chip, SQB_IO is the MCU control IO of the safety MOS tube, VSF is the ARMING output of the ignition chip, and SAF_FET_DIAG is the MCU control IO of the MOS tube detection.

[0086] The working process is as follows: First, VER is fully charged by the charging circuit and then goes to SSXY through diode D6 and R13. The SSXY chip has its own AD detection. SSXY ≈VER (i.e. the total voltage drop of the first circuit V drop1 Assigned value 0).

[0087] To summarize, in the step of obtaining the first power supply voltage parameter of the airbag ignition module, by calculating the power supply voltage VER and the total voltage drop of the first circuit (if it is less than the preset zero parameter, it is assigned to 0), the actual power supply voltage of the airbag ignition module can be accurately determined, providing a reliable reference for subsequent short circuit and open circuit detection.

[0088] Example 3: Furthermore, in the step of obtaining the corresponding second supply voltage parameter, the detection module includes a short circuit detection unit, and the short circuit detection unit is a discharge circuit for voltage division, and further includes the following steps: S2011, obtain the voltage division ratio K and the total voltage drop V of the second circuit drop2 ; S2012: According to the voltage division ratio K and the total voltage drop V of the second circuit drop2 , determine the corresponding second supply voltage parameter V SSXY2, where V SSXY2 =K×V drop2 ; In the step of obtaining the corresponding third power supply voltage parameter, the detection module includes a circuit break detection unit, and the circuit break detection unit is used to drive the corresponding MOS tube in the safety power control module to be turned on and in the linear region, and also includes the following steps: S401, obtaining the ignition preparation drive voltage VSF of the airbag ignition module and the gate-source threshold voltage V of the corresponding MOS tube in the safety power control module gsth , and the total voltage drop of the third circuit V drop3 ; S402, according to the gate-source threshold voltage V gsth , and the total voltage drop of the third circuit V drop3 , determine the corresponding third supply voltage parameter V SSXY3 , where V SSXY3 =VSF-V drop3 -V gsth .

[0089] like Figure 2 As shown, the specific working principle can be explained as follows: the MCU then controls the SAF_FET_DIAG pin to be set high, and drives the transistor Q7 through the resistor R15 to generate a discharge loop.

[0090] The circuit is as follows: VER passes through D8, through R13, R14 to ground. Where 0.7 is the tube pressure drop of D8; The microcontroller determines V SSXY The voltage is within a reasonable range, which proves that MOSFET Q9 is not short-circuited. If it is short-circuited, V SSXY The voltage will not decrease, and will still be almost equal to VER; If it is within a reasonable range, the airbag chip will enter the arming state, VSF will output a 25V voltage, and the microcontroller SQB_IO will be set high, so that Q6_A NPN is turned on, Q6_B PNP is turned on, and VSF will drive MOSFET Q9 to turn on through diode D9. At this time V SSXY =VSF-0.7-Vgsth.

[0091] The microcontroller determines V SSXY The voltage is within a reasonable range, which proves that MOSFET Q9 is not broken. If it is broken, V SSXY The voltage will not increase, but will maintain Turn off SQB_IO, VSF, SAF_FET_DIAG, and continue to detect V SSXYIf the voltage is equal to VER, the MOSFET can be turned off. If it is not approximately equal to VER, the MOSFET fails to turn off.

[0092] In summary, in the step of obtaining the second power supply voltage parameter, the voltage division ratio and the total voltage drop of the second circuit are obtained through the voltage division discharge circuit of the short circuit detection unit, and the second power supply voltage parameter is calculated; in the step of obtaining the third power supply voltage parameter, the MOS tube is driven to conduct and the relevant voltage and the total voltage drop of the third circuit are obtained through the open circuit detection unit, and the third power supply voltage parameter is calculated. These steps ensure the accurate acquisition of the voltage parameters required for the accurate evaluation of the short circuit and open circuit states, thereby improving the fault detection effect and control accuracy of the safety MOSFET circuit.

[0093] Embodiment 4: Furthermore, in the step of obtaining the corresponding second supply voltage parameter, the detection module includes a short circuit detection unit, and the short circuit detection unit is a discharge circuit for voltage division, and further includes the following steps: S2021, obtaining the current IC in the discharge loop, the total resistance value R in the safety power control module, and other diode voltage drops VG; S2022: Determine the total voltage drop V of the second circuit according to the current IC, the total resistance value R and other diode voltage drops VG. drop2 , where V drop2 =(IC×R)+VG; S2023, according to the total voltage drop V of the second circuit drop2 , and the supply voltage VER, determine the corresponding second supply voltage parameter V SSXY2 , where V SSXY2 =VER-V drop2 .

[0094] like Figure 3 As shown, the specific working principle can be explained as follows: First, VER is fully charged by the charging circuit, and then passes through diode D5 and R21 to SSXY. The SSXY chip has its own AD detection. V SSXY ≈VER; Then the MCU controls the SAF_FET_DIAG pin to be set high, and drives the transistor Q12_BNPN tube through the resistor R27 to generate a discharge loop.

[0095] The circuit is as follows: VER passes through D5, through R21, R27 to ground. V SSXY =VER-0.7-IC*R21 5V is the voltage of SAF_FET_DIAG IO set high; VE is the E-level voltage of NPN tube 4 pin, β is the NPN amplification factor, and 0.7V is the tube voltage drop of the diode The microcontroller determines V SSXY The voltage is within a reasonable range, which proves that MOSFET Q11 is not short-circuited. If it is short-circuited, V SSXY The voltage will not decrease, and will still be almost equal to VER; If it is within a reasonable range, the airbag chip will enter the arming state, and the microcontroller SQB_IO will be set high, so that Q12_A NPN is turned on, driving MOSFET Q12 to turn on. At this time V SSXY ≈VSF-0.7.

[0096] The microcontroller determines V SSXY The voltage is within a reasonable range, which proves that MOSFET Q9 is not broken. If it is broken, V SSXY The voltage will not increase, it will still maintain V SSXY =VER-0.7-IC*R21 Turn off SQB_IO, VSF, SAF_FET_DIAG, and continue to detect V SSXY If the voltage is equal to VER, the MOSFET can be turned off. If it is not approximately equal to VER, the MOSFET fails to turn off.

[0097] To sum up, further, in the step of obtaining the second supply voltage parameters, the total voltage drop of the second circuit is calculated by measuring the current IC, the total resistance value R and other diode voltage drops VG in the short-circuit detection unit (discharge circuit), and the second supply voltage parameters are determined in combination with the power supply voltage VER, thereby achieving accurate evaluation and alarm of the short-circuit state and enhancing the fault detection and protection performance of the safety MOSFET circuit.

[0098] Those skilled in the art can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example. In actual applications, the above-mentioned functions can be distributed and completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above.

[0099] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A safety MOSFET circuit, characterized in that: It includes a power supply module, a safety power control module, an airbag ignition module, a detection module and an MCU control module, wherein the power output end of the power supply module is connected to the power input end of the safety power control module, the power output end of the safety power control module is connected to the power input end of the airbag ignition module, the power signal input end of the MCU control module is connected to the power signal output end of the airbag ignition module, the signal output end of the MCU control module is connected to the signal input end of the detection module, the short-circuit detection signal input end of the detection module is movably connected to the power output end of the safety power control module, so as to adjust the voltage output by the safety power control module and then perform short-circuit detection of the corresponding MOS tube in the safety power control module, and the open-circuit detection signal output end of the detection module is connected to the signal input end of the safety power control module, so as to adjust the voltage output by the safety power control module and then perform open-circuit detection of the corresponding MOS tube in the safety power control module.

2. A safety MOSFET circuit according to claim 1, characterized in that: The safety power control module includes a MOS tube element, a resistor element and a diode element. The positive terminal of the diode element is connected to the power output terminal of the power supply module, and the negative terminal of the diode element is respectively connected to the first end of the resistor element and the first conduction end of the MOS tube element. The common node between the second end of the resistor element and the second conduction end of the MOS tube element serves as the power output terminal of the safety power control module to be connected to the power input terminal of the airbag ignition module. The negative terminal of the diode element is connected to the power input terminal of the airbag ignition module, and the controlled end of the MOS tube element is connected to the short-circuit detection signal input terminal of the detection module.

3. A safety MOSFET circuit according to claim 2, characterized in that: The detection module includes a short-circuit detection unit and a circuit-break detection unit. The power input end of the short-circuit detection unit serves as the short-circuit detection signal input end of the detection module. The signal input end of the short-circuit detection unit is connected to the short-circuit detection control signal output end of the MCU control module to control the active connection between the power input end of the short-circuit detection unit and the power output end of the safety power control module. The signal input end of the circuit-break detection unit is connected to the circuit-break detection control signal output end of the MCU control module. The signal output end of the circuit-break detection unit serves as the circuit-break detection signal output end of the detection module and is connected to the signal input end of the safety power control module.

4. A safety MOSFET circuit according to claim 3, characterized in that: The short circuit detection unit includes a transistor Q7, a resistor R14, a resistor R15 and a resistor R16, the second end of the resistor element is connected to the first end of the resistor R14, and the common node between the second end of the resistor element and the first end of the resistor R14 is connected to the power input end of the airbag ignition module, the second end of the resistor R14 is connected to the first conduction end of the transistor Q7, the second conduction end of the transistor Q7 is grounded, the controlled end of the transistor Q7 is connected to the first end of the resistor R15, the second end of the resistor R15 is connected to the first end of the resistor R16, the second end of the resistor R16 is grounded, and the common node between the second end of the resistor R15 and the first end of the resistor R16 is connected to the short circuit detection control signal output end of the MCU control module.

5. A safety MOSFET circuit according to claim 3, characterized in that: The circuit break detection unit includes a transistor Q6-A, a transistor Q6-B, a resistor R18, a resistor R17 and a diode D9. The controlled end of the transistor Q6-A is connected to the circuit break detection control signal output end of the MCU control module, the first conducting end of the transistor Q6-A is grounded, the second conducting end of the transistor Q6-A is connected to the controlled end of the transistor Q6-B, the first conducting end of the transistor Q6-B is connected to the first end of the resistor R17, the second end of the resistor R17 is grounded, the common node between the first conducting end of the transistor Q6-B and the first end of the resistor R17 is connected to the ignition preparation drive port of the airbag ignition module, the second conducting end of the transistor Q6-B is connected to the positive end of the diode D9, and the negative end of the diode D9 is connected to the controlled end of the MOS tube element.

6. A safety MOSFET circuit according to claim 2, characterized in that: The detection module includes a control management chip Q12, a resistor R23, a resistor R24, a resistor R26 and a resistor R27. The control management chip Q12 is provided with a transistor Q12-A and a transistor Q12-B. The first end of the resistor R27 is connected to the controlled end of the transistor Q12-B, the second end of the resistor R27 is connected to the short-circuit detection control signal output end of the MCU control module, the first conduction end of the transistor Q12-B is connected to the first end of the resistor R26, and the first end of the resistor R26 is connected to the short-circuit detection control signal output end of the MCU control module. The two ends are grounded, the second conduction end of the transistor Q12-B is connected to the power output end of the safety power control module, the first end of the resistor R24 ​​is connected to the circuit breaker detection control signal output end of the MCU control module, the second end of R24 is connected to the controlled end of the transistor Q12-A, the first conduction end of the transistor Q12-A is connected to the controlled end of the MOS tube element, the second conduction end of the transistor Q12-A is connected to the first end of the resistor R23, and the second end of the resistor R23 is grounded.

7. A control method for a safety MOSFET circuit, applied to a safety MOSFET circuit as claimed in any one of claims 1 to 6, characterized in that: The following steps are involved: Acquire a first power supply voltage parameter of an airbag ignition module; Controlling the detection module to perform short circuit detection and obtain corresponding second supply voltage parameters; Comparing the first supply voltage parameter with the second supply voltage parameter to generate a corresponding short-circuit state evaluation parameter, wherein the short-circuit state evaluation parameter is used to generate a corresponding alarm instruction; Determine whether the detection module performs open circuit detection according to the short circuit state evaluation parameter, and if it is determined to perform open circuit detection, obtain the corresponding third power supply voltage parameter; The second supply voltage parameter and the third supply voltage parameter are compared to generate a corresponding disconnection state evaluation parameter, wherein the disconnection state evaluation parameter is used to generate a corresponding alarm instruction.

8. The control method of a safety MOSFET circuit according to claim 7, characterized in that: The step of obtaining the first power supply voltage parameter of the airbag ignition module includes: Get the power supply voltage VER of the power supply module and the total voltage drop V of the first circuit drop1 , where the total voltage drop of the first circuit V drop1 When the parameter is less than the preset zero parameter, the total pressure drop V drop1 Assign a value of 0; According to the power supply voltage VER and the total voltage drop V drop1 , determine the corresponding first supply voltage parameter V SSXY1 , where V SSXY1 =VER-V drop1 .

9. A control method for a safety MOSFET circuit according to claim 8, characterized in that: In the step of obtaining the corresponding second supply voltage parameter, the detection module includes a short circuit detection unit, and the short circuit detection unit is a discharge circuit for voltage division, and further includes the following steps: Get the voltage division ratio K and the total voltage drop V of the second circuit drop2 ; According to the voltage division ratio K and the total voltage drop V of the second circuit drop2 , determine the corresponding second supply voltage parameter V SSXY2 , where V SSXY2 =K×V drop2 ; In the step of obtaining the corresponding third power supply voltage parameter, the detection module includes a circuit break detection unit, and the circuit break detection unit is used to drive the corresponding MOS tube in the safety power control module to be turned on and in the linear region, and also includes the following steps: obtaining the ignition preparation drive voltage VSF of the airbag ignition module, the gate-source threshold voltage V gsth , and the total voltage drop of the third circuit V drop3 ; According to the gate-source threshold voltage V gsth , and the total voltage drop of the third circuit V drop3 , determine the corresponding third supply voltage parameter V SSXY3 , where V SSXY3 =VSF-V drop3 -V gsth .

10. The control method of a safety MOSFET circuit according to claim 8, characterized in that: In the step of obtaining the corresponding second supply voltage parameter, the detection module includes a short circuit detection unit, and the short circuit detection unit is a discharge circuit for voltage division, and further includes the following steps: Obtaining the current IC in the discharge loop, the total resistance value R in the safety power control module, and other diode voltage drops VG; Determine the total voltage drop V of the second circuit according to the current IC, the total resistance value R and other diode voltage drops VG. drop2 , where V drop2 =(IC×R)+VG; According to the total voltage drop V of the second circuit drop2 , and the supply voltage VER, determine the corresponding second supply voltage parameter V SSXY2 , where V SSXY2 =VER-V drop2 .

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