Hot plug protection circuit applied to OBD interface and electronic equipment

Abstract

The utility model discloses a hot plug protection circuit applied to an OBD interface and an electronic device, the circuit comprises a pin protection module, a pin switch module, a main control module and a power supply module, the pin protection module executes pin protection processing operation on a first signal input by the OBD interface to obtain a second signal result; performing corresponding voltage conversion operation on the second signal result through the power supply module to obtain a voltage conversion result; on-off control operation is executed through the main control module according to the signal level information, and the magnitude of current flowing through the pin switch module is adjusted according to an on-off control result; the power-on condition is determined through the pin switch module according to the magnitude of the current, and the connection or disconnection of a target pin included in the OBD interface is controlled according to the power-on condition. Therefore, according to the utility model, the hot plug protection function of the OBD interface can be realized, and when the protection device is connected to the vehicle through the OBD interface, the internal bus of the vehicle is not interfered by signals, and the protection device is not burnt out due to crosstalk of a power supply of the OBD interface of the vehicle.

Description

Technical Field

[0001] The utility model relates to the technical field of protection circuits, and particularly relates to a hot plug protection circuit and an electronic device applied to an OBD interface. Background Art

[0002] With the rapid development of automotive technology, the On Board Diagnostics (OBD) system has become an indispensable part of modern vehicles. It not only provides great convenience for vehicle fault diagnosis and repair but also promotes the wide application of various in-vehicle electronic devices based on the OBD interface. However, in practical applications, there are compatibility and safety issues with hot plugging of the OBD interface. That is, when devices are plugged or unplugged while the vehicle power supply is not completely turned off, it may cause damage to the interface, interruption of data transmission, or even abnormal operation of the vehicle electrical system. In addition, the instantaneous current and voltage fluctuations generated during the hot plugging process may also damage the OBD interface and the electronic devices connected thereto, and may also introduce electromagnetic interference, affecting the normal operation of other vehicle systems. Therefore, it is particularly important to provide a new circuit to implement the hot plug protection function of the OBD interface, thereby reducing the interference and damage caused by device interface plugging and unplugging. Summary of the Utility Model

[0003] The utility model provides a hot plug protection circuit and an electronic device applied to an OBD interface, which can implement the hot plug protection function of the OBD interface, thereby reducing the interference and damage caused by device interface plugging and unplugging.

[0004] To solve the above technical problems, in the first aspect, the utility model discloses a hot plug protection circuit applied to an OBD interface. The circuit includes a pin protection module, a pin switch module, a main control module, and a power supply module, where:

[0005] The first end of the pin protection module is used to be electrically connected to the first end of the OBD interface. The second end of the pin protection module is electrically connected to the first end of the power supply module. The second end of the power supply module is electrically connected to the first end of the pin switch module. The third end of the power supply module is electrically connected to the first end of the main control module. The second end of the main control module is electrically connected to the second end of the pin switch module. The third end of the pin switch module is electrically connected to the third end of the pin protection module;

[0006] The pin protection module is configured to receive a first signal transmitted by the OBD interface, perform a pin protection processing operation based on the first signal to obtain a second signal result, and transmit the second signal result to the power supply module and the pin switch module respectively;

[0007] The power supply module is used to perform corresponding voltage conversion operations on the second signal result according to voltage conversion requirements to obtain a voltage conversion result, and transmit the voltage conversion result to the main control module and the pin switch module respectively;

[0008] The main control module is used to perform on-off control operations according to signal level information to obtain an on-off control result, and adjust the magnitude of the current flowing through the pin switch module according to the on-off control result;

[0009] The pin switch module is used to determine the power-on situation according to the magnitude of the current input by the main control module, and control the conduction or cutoff of the target pins included in the OBD interface according to the power-on situation.

[0010] As an optional implementation manner, in the first aspect of the present utility model, the pin protection module includes a first pin protection circuit and a second pin protection circuit, and the OBD interface includes a first OBD interface and a second OBD interface, wherein:

[0011] The first end of the first pin protection circuit is electrically connected to the first OBD interface, and the second end of the first pin protection circuit is electrically connected to the third end of the pin switch module;

[0012] The first end of the second pin protection circuit is electrically connected to the second OBD interface, and the second end of the second pin protection circuit is electrically connected to the first end of the power supply module.

[0013] As an optional implementation manner, in the first aspect of the present utility model, the first pin protection circuit includes one or more first pin protection sub-circuits, the first OBD interface includes one or more OBD sub-interfaces, and each OBD sub-interface has a corresponding first pin protection sub-circuit, wherein:

[0014] For any one of the OBD sub-interfaces, the first end of the first pin protection sub-circuit corresponding to the OBD sub-interface is electrically connected to the OBD sub-interface, and the second end of the first pin protection sub-circuit corresponding to the OBD sub-interface is electrically connected to the third end of the pin switch module.

[0015] As an optional implementation manner, in the first aspect of the present utility model, the second pin protection circuit includes a second current limiting protection circuit, a second strong electric pulse absorption circuit and an anti-backflow circuit, wherein:

[0016] The first end of the second current limiting protection circuit is used to be electrically connected to the second OBD interface, the second end of the second current limiting protection circuit is electrically connected to the first end of the second strong electric pulse absorption circuit and the first end of the anti-backflow circuit respectively, and the second end of the anti-backflow circuit is electrically connected to the first end of the power supply module;

[0017] The second current-limiting protection circuit is configured to perform a current-limiting operation on the first input current signal input through the second OBD interface;

[0018] The second high-voltage pulse absorption circuit is configured to perform a high-voltage impact pulse absorption operation on the first input current signal input through the second OBD interface;

[0019] The anti-backflow circuit is configured to perform an anti-backflow operation on the first input current signal input through the second OBD interface.

[0020] As an alternative implementation, in the first aspect of the present invention, the power supply module includes a first power conversion circuit and a second power conversion circuit, and the main control module includes a main control circuit, wherein:

[0021] The first end of the first power conversion circuit is electrically connected to the second end of the pin protection module, the second end of the first power conversion circuit is electrically connected to the first end of the main control circuit, the third end of the first power conversion circuit is electrically connected to the first end of the second power conversion circuit, the second end of the second power conversion circuit is electrically connected to the second end of the main control circuit, and the third end of the main control circuit is electrically connected to the first end of the pin switch module;

[0022] The first power conversion circuit is configured to convert the first voltage input through the OBD interface into a second voltage according to the first voltage requirement of the main control module, and transmit the second voltage to the main control module;

[0023] The second power conversion circuit is configured to convert the first voltage input through the OBD interface into a third voltage according to the second voltage requirement of the pin switch module;

[0024] The main control circuit is configured to determine the power conduction control condition of the pin switch module according to the level condition of the determined power supply setting signal. When the power conduction control condition is to control the power supply to conduct, it controls the third voltage to be transmitted to the pin switch module.

[0025] As an alternative implementation, in the first aspect of the present invention, each of the first pin protection sub-circuits includes an electrostatic pulse absorption circuit, a first current-limiting protection circuit, and a first high-voltage pulse absorption circuit, wherein:

[0026] For any one of the first pin protection sub - circuits, the first ends of the electrostatic pulse absorption circuit and the first current - limiting protection circuit in the first pin protection sub - circuit are both electrically connected to the OBD sub - interface corresponding to the first pin protection sub - circuit, and the first ends of the first high - voltage pulse absorption circuit and the second end of the first current - limiting protection circuit in the first pin protection sub - circuit are both electrically connected to the third end of the pin switch module;

[0027] The electrostatic pulse absorption circuit is used to perform an electrostatic shock pulse absorption operation on the second input current signal input by the OBD sub - interface;

[0028] The first current - limiting protection circuit is used to perform a current - limiting operation on the second input current signal input by the OBD sub - interface;

[0029] The first high - voltage pulse absorption circuit is used to perform a high - voltage shock pulse absorption operation on the second input current signal input by the OBD sub - interface.

[0030] As an optional implementation manner, in the first aspect of the present utility model, the pin switch module includes one or more pin switch circuits, and each pin switch circuit has a corresponding first pin protection sub - circuit, where:

[0031] For any one of the pin switch circuits, the second end of the first pin protection sub - circuit corresponding to the pin switch circuit is electrically connected to the first end of the pin switch circuit, and the second end of the pin switch circuit is electrically connected to the third end of the main control circuit.

[0032] As an optional implementation manner, in the first aspect of the present utility model, each pin switch circuit includes a signal isolation circuit, a voltage supply circuit, and a switch control circuit, where:

[0033] For any one of the pin switch circuits, the first end of the signal isolation circuit in the pin switch circuit is electrically connected to the third end of the main control circuit, the second end of the signal isolation circuit in the pin switch circuit is electrically connected to the first end of the voltage supply circuit in the pin switch circuit, the second end of the voltage supply circuit in the pin switch circuit is electrically connected to the first end of the switch control circuit in the pin switch circuit, the third end of the voltage supply circuit in the pin switch circuit is electrically connected to the second end and the third end of the switch control circuit in the pin switch circuit respectively, the fourth end of the voltage supply circuit in the pin switch circuit is electrically connected to the fourth end of the switch control circuit in the pin switch circuit, and the fifth end of the switch control circuit in the pin switch circuit is electrically connected to the second end of the first pin protection sub - circuit corresponding to the pin switch circuit;

[0034] The voltage supply circuit is used to supply a voltage signal to the switch control circuit when the target port is in the powered - on state;

[0035] The switch control circuit is configured to perform a line conduction operation when receiving the voltage signal transmitted by the voltage supply circuit;

[0036] The signal isolation circuit is configured to perform a signal isolation operation on corresponding pins in the OBD interface.

[0037] As an optional implementation manner, in the first aspect of the present invention, the main control circuit includes a power signal conduction circuit and a main control chip, wherein:

[0038] The first end of the power signal conduction circuit is electrically connected to the second end of the second power conversion circuit, the second end of the power signal conduction circuit is electrically connected to the first end of the pin switch module, the third end of the power signal conduction circuit is electrically connected to the first end of the main control chip, and the power supply terminal of the main control chip is configured to be electrically connected to the second end of the first power conversion circuit;

[0039] The main control chip is configured to send a level signal for a power supply setting signal to the power signal conduction circuit;

[0040] The power signal conduction circuit is configured to perform a power signal turn-off operation when the level signal is used to represent a pull-down level, so that the third voltage cannot be transmitted to the pin switch module; and perform a power signal conduction operation when the level signal is used to represent a high level, so that the third voltage can be transmitted to the pin switch module.

[0041] A second aspect of the present invention discloses an electronic device, which includes a hot-swap protection circuit applied to an OBD interface as disclosed in any one of the first aspect.

[0042] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0043] The present utility model provides a hot plug protection circuit and an electronic device applied to an OBD interface. The circuit includes: a pin protection module, a pin switch module, a main control module, and a power supply module, where: the first signal transmitted by the OBD interface is received through the pin protection module, and a pin protection processing operation is performed based on the first signal to obtain a second signal result, and the second signal result is respectively transmitted to the power supply module and the pin switch module; according to the voltage conversion requirement, the power supply module performs corresponding voltage conversion operations on the second signal result to obtain a voltage conversion result, and the voltage conversion result is respectively transmitted to the main control module and the pin switch module; the main control module performs on-off control operations according to the signal level information to obtain an on-off control result, and adjusts the current flowing through the pin switch module according to the on-off control result; the pin switch module determines the power-on situation according to the current magnitude input by the main control module, and controls the conduction or cut-off of the target pin included in the OBD interface according to the power-on situation. It can be seen that the present utility model can perform hot plug protection operations based on pin signal protection, targeted power supply voltage conversion, pin switch control, and line on-off control when the device is connected to the OBD interface, can realize the hot plug protection function of the OBD interface, is beneficial to improving the accuracy and reliability of the hot plug protection of the OBD interface, and is also beneficial to improving the timeliness, convenience, and effectiveness of the hot plug protection of the OBD interface. Furthermore, it is beneficial to protect the internal bus of the vehicle from signal interference when the device is connected to the vehicle through the OBD interface and protect the device from being burned out by the power supply crosstalk of the automotive OBD interface. In addition, this circuit is applicable to all brand models using the OBD standard interface, which is beneficial to improving the application universality of the hot plug protection of the OBD interface. In addition, this circuit occupies less MCU resources and has a simple logic, which is beneficial to reducing the R & D implementation cost and development cycle of the hot plug protection. Description of the Drawings

[0044] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model, the drawings required for the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present utility model. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0045] Figure 1 It is a schematic structural diagram of a hot plug protection circuit applied to an OBD interface disclosed in an embodiment of the present utility model;

[0046] Figure 2 It is a schematic structural diagram of another hot plug protection circuit applied to an OBD interface disclosed in an embodiment of the present utility model;

[0047] Figure 3 It is a schematic structural diagram of yet another hot plug protection circuit applied to an OBD interface disclosed in an embodiment of the present utility model;

[0048] Figure 4 It is a schematic structural diagram of a second pin protection circuit, a first power conversion circuit and a second power conversion circuit disclosed in an embodiment of the present utility model;

[0049] Figure 5 It is a schematic structural diagram of another hot-plug protection circuit applied to an OBD interface disclosed in an embodiment of the present utility model;

[0050] Figure 6 It is a schematic structural diagram of a first pin protection circuit and an OBD interface disclosed in an embodiment of the present utility model;

[0051] Figure 7 It is a schematic structural diagram of another hot-plug protection circuit applied to an OBD interface disclosed in an embodiment of the present utility model;

[0052] Figure 8 It is a schematic structural diagram of a pin switch circuit disclosed in an embodiment of the present utility model;

[0053] Figure 9 It is a schematic structural diagram of a power signal conduction circuit and a main control chip disclosed in an embodiment of the present utility model;

[0054] Figure 10 It is an architecture diagram of a hot-plug protection circuit applied to an OBD interface disclosed in an embodiment of the present utility model;

[0055] Figure 11 It is a schematic structural diagram of an electronic device disclosed in an embodiment of the present utility model. Specific embodiments

[0056] For better understanding and implementation, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0057] It should be noted that, unless otherwise clearly specified and defined, the term "electrically connected" in the description, claims and the above-mentioned drawings of the present utility model should be understood in a broad sense. For example, it can be a fixed electrical connection, a detachable electrical connection, or an integral electrical connection; it can be a mechanical electrical connection, an electrical electrical connection or can communicate with each other; it can be directly connected, or indirectly connected through an intermediate medium, and can be the communication inside two components or the interaction relationship between two components. In addition, the terms "first", "second", etc. in the description, claims and the above-mentioned drawings of the present utility model are used to distinguish different objects, rather than to describe a specific order. The terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0058] Embodiment 1

[0059] Please refer to Figure 1 , Figure 1 which is a schematic structural diagram of a hot-plug protection circuit applied to an OBD interface disclosed in an embodiment of the present utility model. Among them, Figure 1 The described hot-plug protection circuit applied to the OBD interface can be applied to an automotive general diagnostic instrument, or can be applied to other devices or apparatuses that require hot-plug protection for the OBD interface. The embodiments of the present utility model do not make any limitations. As Figure 1 shown, the circuit includes: a pin protection module 101, a pin switch module 102, a main control module 103 and a power supply module 104, where:

[0060] The first end of the pin protection module 101 is used to be electrically connected to the first end of the OBD interface 105. The second end of the pin protection module 101 is electrically connected to the first end of the power supply module 104. The second end of the power supply module 104 is electrically connected to the first end of the pin switch module 102. The third end of the power supply module 104 is electrically connected to the first end of the main control module 103. The second end of the main control module 103 is electrically connected to the second end of the pin switch module 102. The third end of the pin switch module 102 is electrically connected to the third end of the pin protection module 101;

[0061] The pin protection module 101 is configured to receive the first signal transmitted by the OBD interface 105, perform a pin protection processing operation based on the first signal to obtain a second signal result, and transmit the second signal result to the power supply module 104 and the pin switch module 102 respectively;

[0062] The power supply module 104 is configured to perform a corresponding voltage conversion operation on the second signal result according to the voltage conversion requirement to obtain a voltage conversion result, and transmit the voltage conversion result to the main control module 103 and the pin switch module 102 respectively;

[0063] The main control module 103 is configured to perform on / off control operations according to the signal level information, obtain an on / off control result, and adjust the magnitude of the current flowing through the pin switch module 102 according to the on / off control result;

[0064] The pin switch module 102 is configured to determine the power-on situation according to the magnitude of the current input by the main control module 103, and control the conduction or cutoff of the target pins included in the OBD interface 105 according to the power-on situation.

[0065] Optionally, the pin protection module transmits power to the power module, which is not limited in the embodiments of the present invention.

[0066] Optionally, the pin protection module and the pin switch module transmit signals back and forth, which is not limited in the embodiments of the present invention.

[0067] Optionally, the main control module can be understood as a group of circuits controlled by the built-in program of the MCU, which realizes functions such as signal control / logic judgment, etc., and is not limited in the embodiments of the present invention.

[0068] Optionally, the pin protection module can be understood as a group of circuits that absorb electrical impact pulses and limit impact current, which is not limited in the embodiments of the present invention.

[0069] Optionally, the power module can be understood as a group of power conversion circuits that convert the voltage output by the OBD interface on the vehicle into a stable voltage required by the main control module and the pin switch module, which is not limited in the embodiments of the present invention.

[0070] Optionally, the pin switch module can be understood as a group of circuits controlled by the main control module to realize the conduction / cutoff functions of the pins of the OBD interface, which is not limited in the embodiments of the present invention.

[0071] Optionally, the OBD interface can be understood as a standard male OBD connector of an automobile. By connecting to the automobile through the OBD interface, the device is connected to the automobile bus network, which is not limited in the embodiments of the present invention.

[0072] It can be seen that implementing Figure 1The described hot-plug protection circuit applied to the OBD interface can perform hot-plug protection operations based on pin signal protection, targeted conversion of power supply voltage, pin switch control, and line on / off control when a device is connected to the OBD interface, can implement the hot-plug protection function of the OBD interface, is beneficial to improving the accuracy and reliability of the hot-plug protection of the OBD interface, and is also beneficial to improving the timeliness, convenience, and effectiveness of the hot-plug protection of the OBD interface. Furthermore, it is beneficial to protect the internal bus of the vehicle from signal interference when the device is connected to the vehicle through the OBD interface and protect the device from being burned out by the power crosstalk of the vehicle OBD interface. In addition, this circuit is applicable to all brand models using the OBD standard interface, which is beneficial to improving the application universality of the hot-plug protection of the OBD interface. Moreover, this circuit occupies less MCU resources and has a simple logic, which is beneficial to reducing the R & D implementation cost and development cycle of the hot-plug protection.

[0073] In an alternative embodiment, Figure 2 is a schematic structural diagram of another hot-plug protection circuit applied to the OBD interface disclosed in the embodiment of the present invention. As Figure 2 shown, the pin protection module 101 includes a first pin protection circuit 1011 and a second pin protection circuit 1012, and the OBD interface 105 includes a first OBD interface 1051 and a second OBD interface 1052, where:

[0074] The first end of the first pin protection circuit 1011 is electrically connected to the first OBD interface 1051, and the second end of the first pin protection circuit 1011 is electrically connected to the third end of the pin switch module 102;

[0075] The first end of the second pin protection circuit 1012 is electrically connected to the second OBD interface 105, and the second end of the second pin protection circuit 1012 is electrically connected to the first end of the power supply module 104.

[0076] Optionally, the OBD interface can refer to JP1 and JP2 as shown in Figure 3 ; further, the first OBD interface can refer to pins 1 to 3, 6 to 8 in JP1 and pins 2 to 8 in JP2 as shown in Figure 3 , and the second OBD interface can refer to pin 5 in JP1 as shown in Figure 3 . The embodiment of the present invention does not make any limitations.

[0077] Optionally, the second end of the first pin protection circuit can be the OBD_P1 - OBD_P15 ports as shown in Figure 3 ; the second end of the second pin protection circuit can correspond to the OBDIN port as shown in Figure 3 . The embodiment of the present invention does not make any limitations.

[0078] It can be seen that the embodiment of the present utility model can perform pin signal protection through the first pin protection circuit or the second pin protection circuit, and can perform pin protection regardless of the different pins of the OBD interface, which is beneficial to improving the pertinence, diversity and comprehensiveness of the first pin protection circuit and the second pin protection circuit, and further beneficial to improving the intelligence of pin protection for different pins, thereby being beneficial to improving the pin signal protection effect of the pin signal.

[0079] In another optional embodiment, Figure 3 is a schematic structural diagram of another hot plug protection circuit applied to the OBD interface disclosed in the embodiment of the present utility model. As Figure 3 shown, the first pin protection circuit 1011 includes one or more first pin protection sub - circuits, the first OBD interface 105 includes one or more OBD sub - interfaces, and each OBD sub - interface has a corresponding first pin protection sub - circuit, where:

[0080] For any OBD sub - interface, the first end of the first pin protection sub - circuit corresponding to this OBD sub - interface is electrically connected to this OBD sub - interface, and the second end of the first pin protection sub - circuit corresponding to this OBD sub - interface is electrically connected to the third end of the pin switch module 102.

[0081] Optionally, the first pin protection circuit can refer to the circuit formed by D30 - D42, F2 - F14 and D1 - D13 as Figure 3 shown; the second pin protection circuit can refer to the circuit formed by F1, D25 and D14 as Figure 3 shown, and the embodiment of the present utility model does not make any limitations.

[0082] It can be seen that the embodiment of the present utility model can perform pin protection through one or more first pin protection sub - circuits, and can perform pin signal processing protection on the input signal regardless of the number of OBD sub - interfaces, which is beneficial to improving the pertinence, matching and specificity between the OBD sub - interface and the first pin protection sub - circuit, and further beneficial to improving the diversity and comprehensiveness of the input signal of the OBD sub - interface, thereby being beneficial to improving the pin protection efficiency and convenience of the input signal of the OBD sub - interface.

[0083] In yet another optional embodiment, Figure 4 is a schematic structural diagram of a second pin protection circuit, a first power conversion circuit and a second power conversion circuit disclosed in the embodiment of the present utility model. As Figure 4 shown, the second pin protection circuit 1012 includes a second current limiting protection circuit, a second strong electric pulse absorption circuit and an anti - backflow circuit, where:

[0084] The first end of the second current-limiting protection circuit is used for electrically connecting to the second OBD interface 105. The second end of the second current-limiting protection circuit is electrically connected to the first end of the second strong electrical pulse absorption circuit and the first end of the anti-backflow circuit respectively. The second end of the anti-backflow circuit is electrically connected to the first end of the power supply module 104.

[0085] The second current-limiting protection circuit is used to perform current-limiting operation on the first input current signal input by the second OBD interface 105.

[0086] The second strong electrical pulse absorption circuit is used to perform strong electrical impulse absorption operation on the first input current signal input by the second OBD interface 105.

[0087] The anti-backflow circuit is used to perform anti-backflow operation on the first input current signal input by the second OBD interface 105.

[0088] Optionally, the second current-limiting protection circuit may include a second current-limiting resistor, the second strong electrical pulse absorption circuit may include a second suppression diode, and the anti-backflow circuit may include an anti-backflow diode, where:

[0089] The first end of the second current-limiting resistor is used for electrically connecting to the second OBD interface. The second end of the second current-limiting resistor is electrically connected to the first end of the second suppression diode and the first end of the anti-backflow diode respectively. The second end of the anti-backflow diode is electrically connected to the first end of the power supply module 104.

[0090] Further optionally, the second suppression diode may be a transient voltage suppression diode, and the anti-backflow diode may be a common diode. The embodiments of the present invention do not make limitations.

[0091] Optionally, the second current-limiting protection circuit may refer to Figure 4 the F1 component shown, the second strong electrical pulse absorption circuit may refer to Figure 4 the D14 component shown, and the anti-backflow circuit may refer to Figure 4 the D25 component shown. The embodiments of the present invention do not make limitations.

[0092] Optionally, the second current-limiting protection circuit can be understood as performing current-limiting protection on the current circuit corresponding to the second OBD interface. The embodiments of the present invention do not make limitations.

[0093] Optionally, the second strong electrical pulse absorption circuit can be understood as absorbing the stronger electrical impulse coming in from the second OBD interface. The embodiments of the present invention do not make limitations.

[0094] It can be seen that the embodiment of the present utility model can achieve the second pin protection function through the second current limiting protection circuit, the second strong electric pulse absorption circuit, and the anti-backflow circuit, improving the comprehensiveness, integrity, and rationality of the second pin protection circuit. It can prevent the current signal input by the second OBD interface from being too large and damaging circuit components, improving the transmission stability and reliability of signals, and further improving the operation stability and safety of the circuit and electronic devices. In addition, it can also suppress and absorb strong pulse voltages or currents, reduce the generation of overvoltage and overcurrent, suppress the rapid change of the voltage and current change rate, and reduce electromagnetic interference and power supply noise. In addition, it can also prevent current backflow, avoid damaging components, improve the safety and stability of components, and further improve the operation stability of the circuit and ensure the operation performance.

[0095] In another optional embodiment, Figure 5 is a schematic structural diagram of another hot plug protection circuit for an OBD interface disclosed in the embodiment of the present utility model. As Figure 5 shown, the power supply module 104 includes a first power conversion circuit and a second power conversion circuit, and the main control module 103 includes a main control circuit, where:

[0096] The first end of the first power conversion circuit is electrically connected to the second end of the pin protection module 101, the second end of the first power conversion circuit is electrically connected to the first end of the main control circuit, the third end of the first power conversion circuit is electrically connected to the first end of the second power conversion circuit, the second end of the second power conversion circuit is electrically connected to the second end of the main control circuit, and the third end of the main control circuit is electrically connected to the first end of the pin switch module 102;

[0097] The first power conversion circuit is used to convert the first voltage input by the OBD interface 105 into a second voltage according to the first voltage requirement of the main control module 103 and transmit the second voltage to the main control module 103;

[0098] The second power conversion circuit is used to convert the first voltage input by the OBD interface 105 into a third voltage according to the second voltage requirement of the pin switch module 102;

[0099] The main control circuit is used to determine the power conduction control situation of the pin switch module 102 according to the level situation of the determined power setting signal. When the power conduction control situation is to control the power to conduct, it controls the third voltage to be transmitted to the pin switch module 102.

[0100] Optionally, after the OBD signal and the power supply are protected by the pin protection module, they respectively enter the pin switch module and the power supply module. Further, the power supply module can be divided into a power conversion circuit for the MCU circuit (i.e., the first power conversion circuit) and a power conversion circuit for the pin switch circuit (i.e., the second power conversion circuit), which is not limited in the embodiment of the present utility model.

[0101] Optionally, for the specific electronic components involved in the first power conversion circuit and their connection relationships, and for the specific electronic components involved in the second power conversion circuit and their connection relationships, please refer to Figure 4 shown below.

[0102] Optionally, the first power conversion circuit can be understood as converting the voltage of about 12V on the automotive OBD pin into a stable 3.3V voltage required for the operation of the main control module. The embodiments of the present invention do not make any limitations in this regard.

[0103] Optionally, the second power conversion circuit can be understood as converting the voltage of about 12V on the automotive OBD pin into a stable 23V voltage required for the operation of the pin switch module; further optionally, the first voltage, the second voltage, and the third voltage can be set to different voltage values according to actual requirements. The embodiments of the present invention do not make any limitations in this regard.

[0104] Optionally, when the OBD signal enters the pin switch circuit, the pin switch circuit is default off, and the conduction of the pin switch is controlled by the main control circuit to ensure the transmission timing of the OBD signal: that is, the pin switch circuit is only turned on after the device initialization and the default state configuration of signal transmission and reception are completed, so as to ensure that the hot plugging does not interfere with the in-vehicle bus network and bus signals. At the same time, since the pin switch circuit is default off, the OBD signal will not leak into the power module, and the power module can only draw power from the OBD_IN pin for voltage conversion to supply power for the device to power on and work, thus ensuring the power supply timing, and ultimately ensuring the working timing of the device when hot plugging into the automotive OBD interface. The embodiments of the present invention do not make any limitations in this regard.

[0105] It can be seen that the embodiments of the present invention can realize the power supply voltage function through the first power conversion circuit and the second power conversion circuit, improve the pertinence, diversity, and comprehensiveness of the first power conversion circuit and the second power conversion circuit, and further improve the accuracy and reliability of the voltage supply for the pin switch module and the main control module, and can meet different voltage supply requirements, thereby improving the adjustability of the power supply voltage, the power utilization rate, and the circuit reliability, and to a certain extent improving the operation stability, circuit reliability, and safety of the pin switch module and the main control module. In addition, combined with the main control circuit to control the conduction or off of the pin switch module, it ensures the transmission timing of the OBD signal, the power supply timing of the device when powering on and working, and the working timing of the device when hot plugging into the automotive OBD interface, so as to achieve no interference with the in-vehicle bus network and bus signals during hot plugging.

[0106] In yet another optional embodiment, Figure 6 is a schematic structural diagram of a first pin protection circuit and an OBD interface disclosed in the embodiments of the present invention, as shown in Figure 6As shown, each first pin protection sub-circuit includes an electrostatic pulse absorption circuit, a first current limiting protection circuit, and a first high-voltage pulse absorption circuit, where:

[0107] For any first pin protection sub-circuit, the first end of the electrostatic pulse absorption circuit and the first end of the first current limiting protection circuit in the first pin protection sub-circuit are both electrically connected to the corresponding OBD sub-interface of the first pin protection sub-circuit, and the first end of the first high-voltage pulse absorption circuit and the second end of the first current limiting protection circuit in the first pin protection sub-circuit are both electrically connected to the third end of the pin switch module 102;

[0108] The electrostatic pulse absorption circuit is used to perform an electrostatic shock pulse absorption operation on the second input current signal input from the OBD sub-interface;

[0109] The first current limiting protection circuit is used to perform a current limiting operation on the second input current signal input from the OBD sub-interface;

[0110] The first high-voltage pulse absorption circuit is used to perform a high-voltage shock pulse absorption operation on the second input current signal input from the OBD sub-interface.

[0111] Optionally, the electrostatic pulse absorption circuit can be understood as absorbing the electrostatic shock pulses coming in from the OBD sub-interface, and the embodiments of the present invention do not make any limitations.

[0112] Optionally, the first high-voltage pulse absorption circuit can be understood as absorbing the relatively high-voltage shock pulses coming in from the OBD sub-interface, and the embodiments of the present invention do not make any limitations.

[0113] Optionally, the first current limiting protection circuit can be understood as performing current limiting protection on the current circuit corresponding to the OBD sub-interface, and the embodiments of the present invention do not make any limitations.

[0114] Optionally, the first current limiting protection circuit can refer to Figure 6 the components F2 to F14 shown, the first high-voltage pulse absorption circuit can refer to Figure 6 the components D1 to D13 shown, and the electrostatic pulse absorption circuit can refer to Figure 6 the components D30 to D42 shown, and the embodiments of the present invention do not make any limitations.

[0115] Optionally, the first current limiting protection circuit can include a first current limiting resistor, the first high-voltage pulse absorption circuit can include a first suppression diode, and the electrostatic pulse absorption circuit can include a third suppression diode, where:

[0116] For any first pin protection sub-circuit, the first ends of the third suppression diode and the first current-limiting resistor corresponding to the first pin protection sub-circuit are both electrically connected to the OBD sub-interface corresponding to the first pin protection sub-circuit, and the first ends of the first suppression diode and the second ends of the first current-limiting resistor corresponding to the first pin protection sub-circuit are both electrically connected to the third end of the pin switch module.

[0117] Further optionally, the first suppression diode and the third suppression diode may be transient voltage suppression diodes, which are not limited in the embodiments of the present invention.

[0118] It can be seen that the embodiments of the present invention can implement the first pin protection function through the electrostatic pulse absorption circuit, the first current-limiting protection circuit, and the first strong electrical pulse absorption circuit, improve the comprehensiveness, integrity, and rationality of the first pin protection sub-circuit, prevent the second input current signal input by the OBD sub-interface from being too large and damaging circuit components, improve the transmission stability and reliability of the signal, and further improve the operation stability and safety of the circuit and the electronic device. In addition, it can also suppress and absorb strong pulse voltages or currents, reduce the generation of overvoltage and overcurrent, suppress the rapid change of the voltage and current change rate, reduce electromagnetic interference and power supply noise. In addition, it can also suppress and absorb the pulse voltages or currents generated by electrostatic discharge or other reasons, protect the components in the circuit from damage and reduce electromagnetic interference, improve the overall operation stability and reliability of the circuit, and extend the service life of the circuit and the electronic device.

[0119] In another optional embodiment, Figure 7 is a schematic structural diagram of another hot-swap protection circuit applied to the OBD interface disclosed in the embodiments of the present invention. As Figure 7 shown, the pin switch module 102 includes one or more pin switch circuits, and each pin switch circuit has a corresponding first pin protection sub-circuit, where:

[0120] For any pin switch circuit, the second end of the first pin protection sub-circuit corresponding to the pin switch circuit is electrically connected to the first end of the pin switch circuit, and the second end of the pin switch circuit is electrically connected to the third end of the main control circuit.

[0121] It can be seen that the embodiments of the present invention can perform on-off control of the pins of the OBD interface through one or more pin switch circuits, can perform pin switch control without being limited by the number of pins of the OBD interface, and each OBD interface pin is matched with a dedicated and targeted pin switch circuit, which is beneficial to improving the intelligence of the pin switch control of multiple OBD interface pins, and further beneficial to improving the pertinence, accuracy, and reliability of the pin switch control of the OBD interface pins, and also beneficial to improving the efficiency, convenience, and timeliness of the pin switch control of the OBD interface pins.

[0122] In yet another alternative embodiment, Figure 8 is a schematic structural diagram of a pin switch circuit disclosed in an embodiment of the present utility model, as Figure 8 shown, each pin switch circuit includes a signal isolation circuit, a voltage supply circuit, and a switch control circuit, where:

[0123] For any pin switch circuit, the first end of the signal isolation circuit in the pin switch circuit is electrically connected to the third end of the main control circuit, the second end of the signal isolation circuit in the pin switch circuit is electrically connected to the first end of the voltage supply circuit in the pin switch circuit, the second end of the voltage supply circuit in the pin switch circuit is electrically connected to the first end of the switch control circuit in the pin switch circuit, the third end of the voltage supply circuit in the pin switch circuit is electrically connected to the second end and the third end of the switch control circuit in the pin switch circuit respectively, the fourth end of the voltage supply circuit in the pin switch circuit is electrically connected to the fourth end of the switch control circuit in the pin switch circuit, and the fifth end of the switch control circuit in the pin switch circuit is electrically connected to the second end of the first pin protection sub-circuit corresponding to the pin switch circuit;

[0124] The voltage supply circuit is used to transmit a voltage signal to the switch control circuit when the target port is in the powered-on state;

[0125] The switch control circuit is used to perform a line conduction operation when receiving the voltage signal transmitted by the voltage supply circuit;

[0126] The signal isolation circuit is used to perform a signal isolation operation on the corresponding pin in the OBD interface 105.

[0127] Optionally, as Figure 8 shown, the third end of the main control circuit may correspond to the VSW_+23V_PULL interface, and the second end of the first pin protection sub-circuit may correspond to OBD_P1 to OBD_P15, which is not limited in the embodiment of the present utility model.

[0128] Further optionally, the third end of the pin switch circuit is used to connect to the signal transceiver processing circuit inside the machine; further, as Figure 8 shown, the third end of the pin switch circuit may correspond to OBD_P1_IN to OBD_P15_IN, which is not limited in the embodiment of the present utility model.

[0129] Optionally, the voltage supply circuit may include a first supply resistor and a second supply resistor, the switch control circuit may include a first dual NMOS transistor, and the signal isolation circuit may include a first isolation diode, where:

[0130] For any pin switch circuit, the first end of the first isolation diode corresponding to the pin switch circuit is electrically connected to the third end of the main control circuit, the second end of the first isolation diode corresponding to the pin switch circuit is electrically connected to the first end of the first supply resistor corresponding to the pin switch circuit, and the second ends of the second supply resistors corresponding to the pin switch circuit are respectively electrically connected to the first end of the first dual NMOS transistor corresponding to the pin switch circuit, the first end of the second supply resistor in the pin switch circuit, and the fourth end of the first dual NMOS transistor corresponding to the pin switch circuit. The second end of the second supply resistor in the pin switch circuit is electrically connected to the second end and the third end of the first dual NMOS transistor corresponding to the pin switch circuit, and the fifth end of the first dual NMOS transistor corresponding to the pin switch circuit is electrically connected to the second end of the first pin protection sub-circuit corresponding to the pin switch circuit.

[0131] Further optionally, as Figure 8 shown, the sixth end of the first dual NMOS transistor corresponding to the pin switch circuit can correspond to OBD_P1_IN to OBD_P15_IN, which is not limited in the embodiments of the present invention.

[0132] Optionally, for any pin switch circuit, the voltage supply circuit can refer to Figure 8 the combination of R760 and R756 shown and Figure 8 other similar relationship resistor combinations in Figure 5 shown, the switch control circuit can refer to Q1 to Q13 shown in Figure 8 shown, and the signal isolation circuit can refer to D44 to D56 shown in

[0133] Optionally, the voltage supply circuit can be understood as providing the VGS voltage for the switch control circuit after the MCU controls the power-on of VSW_+23V_PULL, so that the switch control circuit is turned on, which is not limited in the embodiments of the present invention.

[0134] Optionally, the signal isolation circuit can be understood as isolating the pin signals of the corresponding OBD interface, which is not limited in the embodiments of the present invention.

[0135] It can be seen that the embodiments of the present invention can realize the pin switch control function through the signal isolation circuit, the voltage supply circuit and the switch control circuit, can isolate the circuits on both sides from interfering with each other, reduce the mutual interference between circuits, improve the use safety and operation stability of the circuit, improve the quality and stability of the circuit signal, and further improve the accuracy, reliability and integrity of signal transmission. In addition, it can also transmit a voltage signal to the direction switch control circuit when the target port is in the powered-on state, so as to realize the conduction of the circuit, ensuring the transmission timing of the OBD signal, the power supply timing of the device when powered on, and the working timing of the device during the hot plugging of the automotive OBD interface.

[0136] In yet another alternative embodiment, as Figure 5 shown, the main control circuit includes a power signal conduction circuit and a main control chip, where:

[0137] The first end of the power signal conduction circuit is electrically connected to the second end of the second power conversion circuit, the second end of the power signal conduction circuit is electrically connected to the first end of the pin switch module 102, the third end of the power signal conduction circuit is electrically connected to the first end of the main control chip, and the power supply terminal of the main control chip is used to be electrically connected to the second end of the first power conversion circuit;

[0138] The main control chip is used to send a level signal for the power supply setting signal to the power signal conduction circuit;

[0139] The power signal conduction circuit is used to perform a power signal turn-off operation when the level signal is used to represent a pull-down level, so that the third voltage cannot be transmitted to the pin switch module 102; when the level signal is used to represent a high level, perform a power signal conduction operation, so that the third voltage can be transmitted to the pin switch module 102.

[0140] Optionally, for the specific electronic components involved in the power signal conduction circuit and the main control chip and their connection relationships, please refer to Figure 9 shown, which is not limited in the embodiments of the present invention.

[0141] Optionally, as Figure 9 shown, the main control circuit can be understood that the SET_VSW_+23V_ON signal (i.e., the power supply setting signal) is defaulted to pull-down, the P-type triode of the power signal conduction circuit is cut off, and VSW_+23V and VSW_+23V+PULL are turned off; when the control SET_VSW_+23V_ON signal is at a high level, the P-type triode is saturated, and VSW_+23V and VSW_+23V+PULL are turned on, so as to realize the conduction / turn-off of the main control circuit to control the pin switch circuit, which is not limited in the embodiments of the present invention.

[0142] It can be seen that the embodiments of the present invention can realize the conduction or turn-off of the pin switch module through the power signal conduction circuit and the main control chip, control the conduction / turn-off operation of the power signal through the level signal being a pull-down level or a high level, improve the control convenience and efficiency of the pin conduction and turn-off of the OBD interface, as well as improve the control accuracy and reliability of the pin conduction and turn-off of the OBD interface, occupy less MCU resources, have a simple logic, low cost, and high reliability.

[0143] In an alternative embodiment, as Figure 10 shown, Figure 10It is a schematic diagram of the architecture of a hot-swap protection circuit applied to an OBD interface disclosed by the present utility model. Among them, the OBD interface is connected to an automobile, and there is a two-way transmission between the OBD interface and the pin protection module. The pin protection module transmits power unidirectionally to the power supply module. There is a two-way transmission of signals between the pin protection module and the pin switch module. The power supply module transmits unidirectionally to the pin switch module, the power supply module transmits unidirectionally to the main control module, and the main control module transmits unidirectionally to the pin switch module. The embodiments of the present utility model are not limited thereto.

[0144] Embodiment 2

[0145] Please refer to Figure 11 , Figure 11 It is a schematic structural diagram of an electronic device disclosed by an embodiment of the present utility model. The electronic device includes a hot-swap protection circuit applied to an OBD interface as described in any one of Embodiment 1, and the functions that the electronic device can achieve include but are not limited to being able to achieve hot-swap protection of the OBD interface. It should be noted that for a detailed description of a hot-swap protection circuit applied to an OBD interface, please refer to the specific description of the relevant content in Embodiment 1, and this embodiment will not be elaborated here.

[0146] It can be seen that the Figure 11 described electronic device can perform hot-swap protection operations based on pin signal protection, targeted conversion of power supply voltage, pin switch control, and line on / off control when the device is connected to the OBD interface, can achieve the hot-swap protection function of the OBD interface, is beneficial to improving the accuracy and reliability of the hot-swap protection of the OBD interface, and is also beneficial to improving the timeliness, convenience, and effectiveness of the hot-swap protection of the OBD interface. Furthermore, it is beneficial to protect the internal bus of the automobile from signal interference when the device is connected to the vehicle through the OBD interface and protect the device from being burned out by the power supply crosstalk of the automobile OBD interface. In addition, this circuit is applicable to all brand models using the OBD standard interface, which is beneficial to improving the application universality of the hot-swap protection of the OBD interface. In addition, this circuit occupies less MCU resources and has a simple logic, which is beneficial to reducing the R & D implementation cost and development cycle of the hot-swap protection.

[0147] The above has introduced in detail a hot-swap protection circuit applied to an OBD interface and an electronic device disclosed by the embodiments of the present utility model. Specific embodiments are used in this article to elaborate on the principle and implementation manner of the present utility model. However, the above preferred embodiments are not used to limit the present utility model. The description of the above embodiments is only used to help understand the method and its core idea of the present utility model; at the same time, for those of ordinary skill in the art, according to the idea of the present utility model, without departing from the spirit and scope of the present utility model, there will be changes in the specific implementation manner and application scope. Therefore, the protection scope of the present utility model is subject to the scope defined by the claims.

Claims

1. A hot plug protection circuit applied to an OBD interface, characterized in that, The circuit includes a pin protection module, a pin switch module, a main control module, and a power supply module, where: The first end of the pin protection module is used for electrically connecting to the first end of the OBD interface. The second end of the pin protection module is electrically connected to the first end of the power supply module. The second end of the power supply module is electrically connected to the first end of the pin switch module. The third end of the power supply module is electrically connected to the first end of the main control module. The second end of the main control module is electrically connected to the second end of the pin switch module. The third end of the pin switch module is electrically connected to the third end of the pin protection module; The pin protection module is configured to receive a first signal transmitted by the OBD interface, perform a pin protection processing operation based on the first signal to obtain a second signal result, and transmit the second signal result to the power supply module and the pin switch module respectively; The power supply module is configured to perform a corresponding voltage conversion operation on the second signal result according to the voltage conversion requirement to obtain a voltage conversion result, and transmit the voltage conversion result to the main control module and the pin switch module respectively; The main control module is configured to perform an on-off control operation according to the signal level information to obtain an on-off control result, and adjust the magnitude of the current flowing through the pin switch module according to the on-off control result; The pin switch module is configured to determine the power-on situation according to the magnitude of the current input by the main control module, and control the conduction or cut-off of the target pin included in the OBD interface according to the power-on situation.

2. The hot plug protection circuit applied to the OBD interface according to claim 1, characterized in that The pin protection module includes a first pin protection circuit and a second pin protection circuit. The OBD interface includes a first OBD interface and a second OBD interface, where: The first end of the first pin protection circuit is electrically connected to the first OBD interface. The second end of the first pin protection circuit is electrically connected to the third end of the pin switch module; The first end of the second pin protection circuit is electrically connected to the second OBD interface. The second end of the second pin protection circuit is electrically connected to the first end of the power supply module.

3. The hot plug protection circuit applied to the OBD interface according to claim 2, characterized in that The first pin protection circuit includes one or more first pin protection sub-circuits. The first OBD interface includes one or more OBD sub-interfaces. Each OBD sub-interface has a corresponding first pin protection sub-circuit, where: For any one of the OBD sub-interfaces, the first end of the first pin protection sub-circuit corresponding to this OBD sub-interface is electrically connected to this OBD sub-interface, and the second end of the first pin protection sub-circuit corresponding to this OBD sub-interface is electrically connected to the third end of the pin switch module.

4. The hot plug protection circuit applied to the OBD interface according to claim 2, characterized in that, The second pin protection circuit includes a second current limiting protection circuit, a second strong electrical pulse absorption circuit, and an anti-backflow circuit, where: The first end of the second current limiting protection circuit is used for electrically connecting to the second OBD interface. The second end of the second current limiting protection circuit is electrically connected to the first end of the second strong electrical pulse absorption circuit and the first end of the anti-backflow circuit respectively. The second end of the anti-backflow circuit is electrically connected to the first end of the power supply module; The second current limiting protection circuit is used to perform a current limiting operation on the first input current signal input from the second OBD interface; The second high-voltage pulse absorption circuit is used to perform a high-voltage impulse absorption operation on the first input current signal input from the second OBD interface; The anti-backflow circuit is used to perform an anti-backflow operation on the first input current signal input from the second OBD interface.

5. The hot-swap protection circuit applied to the OBD interface according to claim 3, wherein The power supply module includes a first power conversion circuit and a second power conversion circuit, and the main control module includes a main control circuit, where: The first end of the first power conversion circuit is electrically connected to the second end of the pin protection module, the second end of the first power conversion circuit is electrically connected to the first end of the main control circuit, the third end of the first power conversion circuit is electrically connected to the first end of the second power conversion circuit, the second end of the second power conversion circuit is electrically connected to the second end of the main control circuit, and the third end of the main control circuit is electrically connected to the first end of the pin switch module; The first power conversion circuit is used to convert the first voltage input from the OBD interface into a second voltage according to the first voltage requirement of the main control module and transmit the second voltage to the main control module; The second power conversion circuit is used to convert the first voltage input from the OBD interface into a third voltage according to the second voltage requirement of the pin switch module; The main control circuit is used to determine the power conduction control situation of the pin switch module according to the level situation of the determined power supply setting signal. When the power conduction control situation is to control the power supply to conduct, it controls the third voltage to be transmitted to the pin switch module.

6. The hot plug protection circuit applied to the OBD interface according to claim 3, characterized in that, Each of the first pin protection sub-circuits includes an electrostatic pulse absorption circuit, a first current limiting protection circuit, and a first high-voltage pulse absorption circuit, where: For any one of the first pin protection sub-circuits, the first end of the electrostatic pulse absorption circuit and the first end of the first current limiting protection circuit in the first pin protection sub-circuit are both electrically connected to the corresponding OBD sub-interface of the first pin protection sub-circuit, and the first end of the first high-voltage pulse absorption circuit and the second end of the first current limiting protection circuit in the first pin protection sub-circuit are both electrically connected to the third end of the pin switch module; The electrostatic pulse absorption circuit is used to perform an electrostatic impulse absorption operation on the second input current signal input from the OBD sub-interface; The first current limiting protection circuit is used to perform a current limiting operation on the second input current signal input from the OBD sub-interface; The first high-voltage pulse absorption circuit is used to perform a high-voltage impulse absorption operation on the second input current signal input from the OBD sub-interface.

7. The hot-pluggable protection circuit applied to the OBD interface according to claim 5, characterized in that, The pin switch module includes one or more pin switch circuits, and each pin switch circuit has a corresponding first pin protection sub-circuit, where: For any one of the pin switch circuits, the second end of the first pin protection sub-circuit corresponding to the pin switch circuit is electrically connected to the first end of the pin switch circuit, and the second end of the pin switch circuit is electrically connected to the third end of the main control circuit.

8. The hot plug protection circuit applied to the OBD interface according to claim 7, characterized in that, Each of the pin switch circuits includes a signal isolation circuit, a voltage supply circuit, and a switch control circuit, where: For any one of the pin switch circuits, the first end of the signal isolation circuit in the pin switch circuit is electrically connected to the third end of the main control circuit, the second end of the signal isolation circuit in the pin switch circuit is electrically connected to the first end of the voltage supply circuit in the pin switch circuit, the second end of the voltage supply circuit in the pin switch circuit is electrically connected to the first end of the switch control circuit in the pin switch circuit, the third end of the voltage supply circuit in the pin switch circuit is electrically connected to the second end and the third end of the switch control circuit in the pin switch circuit respectively, the fourth end of the voltage supply circuit in the pin switch circuit is electrically connected to the fourth end of the switch control circuit in the pin switch circuit, and the fifth end of the switch control circuit in the pin switch circuit is electrically connected to the second end of the first pin protection sub-circuit corresponding to the pin switch circuit; The voltage supply circuit is configured to transmit a voltage signal to the switch control circuit when the target port is in a powered-on state; The switch control circuit is configured to perform a line conduction operation when receiving the voltage signal transmitted by the voltage supply circuit; The signal isolation circuit is configured to perform signal isolation operations on the corresponding pins in the OBD interface.

9. The hot plug protection circuit applied to the OBD interface according to claim 5, characterized in that, The main control circuit includes a power signal conduction circuit and a main control chip, where: The first end of the power signal conduction circuit is electrically connected to the second end of the second power conversion circuit, the second end of the power signal conduction circuit is electrically connected to the first end of the pin switch module, the third end of the power signal conduction circuit is electrically connected to the first end of the main control chip, and the power supply terminal of the main control chip is configured to be electrically connected to the second end of the first power conversion circuit; The main control chip is configured to send a level signal for the power setting signal to the power signal conduction circuit; The power signal conduction circuit is configured to perform a power signal turn-off operation when the level signal represents a pull-down level, so that the third voltage cannot be transmitted to the pin switch module; and perform a power signal conduction operation when the level signal represents a high level, so that the third voltage can be transmitted to the pin switch module.

10. An electronic device, characterized in that, The electronic device includes a hot plug protection circuit applied to the OBD interface according to any one of claims 1-9.

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