Anti-static protection circuit structure for network signal bus of electronic control unit

Abstract

The present application relates to the field of integrated circuit technology, and particularly relates to an anti-static protection circuit structure for a network signal bus of an electronic control unit. An anti-static protection circuit structure for a network signal bus of an electronic control unit includes a CAN Bus anti-static protection circuit and a LIN Bus anti-static protection circuit. The CAN Bus anti-static protection circuit is electrically connected to an ECU via a CAN Bus signal transceiver, and is sequentially electrically connected to a common mode inductor and a first TVS diode before grounding. The LIN Bus anti-static protection circuit is electrically connected to a LIN Bus signal transmission circuit, the LIN Bus signal transmission circuit is sequentially electrically connected to the ECU via a LIN Bus signal transceiver from a LIN Bus signal input end, one end of a second TVS diode in the LIN Bus anti-static protection circuit is electrically connected between the LIN Bus signal input end and the LIN Bus signal transceiver, and the other end of the second TVS diode is grounded.

Description

Technical Field

[0001] This invention relates to the field of integrated circuit technology, and in particular to an anti-static protection circuit structure for a network signal bus of an electronic control unit. Background Technology

[0002] Static electricity is a group of stationary charges that accumulate temporarily or permanently in a substance and are blocked by a high-resistivity medium, preventing them from flowing out of the substance. Once these charge groups accumulate in large quantities, causing an increase in potential energy, and the isolation conditions of the high-resistivity medium change, such as when a conductive medium approaches the contacted substance, air discharge or contact discharge may occur, causing the charge accumulated on the substance to be released to another substance through the conductive medium.

[0003] On the other hand, most vehicles have an electronic control unit (ECU) installed inside the vehicle (such as a vehicle computer or its peripheral control devices). Since most vehicles are encased in a metal shell, the metal shielding effect provides some protection for the embedded electronic devices. However, most tires are made of insulating rubber. When the vehicle body receives electrical charges released from other substances in the environment, because the rubber tires cannot truly ground the metal shell and allow the accumulated charge to flow back to the ground, a large amount of charge may still accumulate and remain on the metal shell.

[0004] When a user's body or an item they carry (such as a key) comes into contact with the vehicle's metal casing (such as the body, doors, or keyhole), a large amount of charge accumulated on the metal casing may flow to the user's body or the item they are carrying. When the user or their item enters the vehicle and then approaches or comes into contact with the ECU (Electronic Control Unit), it may discharge electricity to the ECU.

[0005] Because an increasing number of electronic control units (ECUs) installed in vehicles now have circuit buses and devices for transmitting network signals, such as the Control Area Network Bus (CAN Bus) and the Local Interconnect Network Bus (LIN Bus), if the aforementioned electrical charge is released to the ECU, it may cause signal distortion transmitted by the CAN Bus and LIN Bus, or even damage to important components (such as the ECU, CAN Bus transceiver, and LIN Bus transceiver), resulting in the inability to continue transmitting network signals normally.

[0006] To test the electrostatic discharge (ESD) resistance of an ECU device under powered operation, the ISO 10605 standard is widely used among existing ESD testing standards. The ISO 10605 standard first constructs an ESD test environment, maintaining the temperature at (23 ± 3)°C and the relative humidity between 20% and 40%. Then, a probe is placed between each exposed surface to perform air discharge (using air as a medium rather than direct contact) and contact discharge into the internal space of the ECU device. After the discharge, the internal components or circuits are inspected for damage or malfunction, which serves as the basis for judging the ECU device's anti-static capability.

[0007] Therefore, there is an urgent need for an anti-static protection circuit structure for the network signal bus of electronic control units to solve the above problems. Summary of the Invention

[0008] The purpose of this invention is to provide an anti-static protection circuit structure for the network signal bus of an electronic control unit, which can withstand a larger amount of static electricity discharge without affecting its network signal transmission function.

[0009] To achieve this objective, the present invention employs the following solution:

[0010] The electrostatic discharge (ESD) protection circuit structure for the network signal bus of an electronic control unit includes:

[0011] A control area network (CLAN) bus electrostatic discharge (ESD) protection circuit is electrically connected to the electronic control unit (ECU) via a CLAN bus transceiver. The CLAN bus ESD protection circuit includes a high-voltage level protection branch circuit and a low-voltage level protection branch circuit. The high-voltage level protection branch circuit is electrically connected to a common-mode inductor and a first transient voltage suppression diode in sequence via the high-potential pin of the CLAN bus transceiver, and then grounded. The low-voltage level protection branch circuit is electrically connected to the common-mode inductor and the first transient voltage suppression diode in sequence via the low-potential pin of the CLAN bus transceiver, and then grounded.

[0012] An electrostatic discharge (ESD) protection circuit for the regional interconnection network (GEM) bus is electrically connected to the GEM bus signal transmission circuit. The GEM bus signal transmission circuit is electrically connected to the electronic control unit from the GEM bus signal input terminal via the GEM bus signal transceiver. The GEM bus ESD protection circuit includes a second transient voltage suppression diode. One end of the second transient voltage suppression diode is electrically connected between the GEM bus signal input terminal and the GEM bus signal transceiver, and the other end of the second transient voltage suppression diode is grounded.

[0013] For example, the control area network bus signal transceiver is a TAJ1040 chip.

[0014] For example, the local area network bus signal transceiver is a TAJ1027 chip.

[0015] For example, the second transient voltage suppression diode can withstand both air discharge voltage and contact discharge voltage of 30kV.

[0016] For example, the second transient voltage suppression diode can withstand an air discharge voltage of 15kV and a contact discharge voltage of 8kV.

[0017] For example, the common mode inductor is a common mode inductor from the ACT45B series.

[0018] The beneficial effects of this invention are as follows:

[0019] The electrostatic discharge (ESD) protection circuit structure for the network signal bus of the electronic control unit provided by this invention can improve the ESD withstand capability of the network signal bus (including the control area network bus and the regional interconnection network bus), so that its related devices (such as the electronic control unit, the control area network bus transceiver and the regional interconnection network bus transceiver) are protected and less prone to damage. Attached Figure Description

[0020] Figure 1 This is a functional block diagram of the anti-static protection circuit structure for the network signal bus of an electronic control unit provided by the present invention;

[0021] Figure 2 This is a circuit diagram of the anti-static protection circuit for the control local area network bus, as well as related peripheral circuits and devices provided by the present invention.

[0022] Figure 3 This is a circuit diagram of the regional interconnection network bus anti-static protection circuit, related peripheral circuits, and devices provided by the present invention.

[0023] In the picture:

[0024] 100. Anti-static protection circuit structure for network signal bus of electronic control unit;

[0025] 200. Control Local Area Network Bus Signal Transceiver;

[0026] 300. Electronic control unit;

[0027] 400. Regional interconnection network bus signal input terminal;

[0028] 500. Regional Interconnect Network Bus Signal Transceiver;

[0029] 1. Control area network bus anti-static protection circuit;

[0030] 11. Common-mode inductor;

[0031] 12. First transient voltage suppression diode;

[0032] 2. Anti-static protection circuit for regional interconnection network bus;

[0033] 21. Second transient voltage suppression diode;

[0034] HVP, high voltage level protection branch circuit;

[0035] LVP, low voltage level protection branch circuit;

[0036] LB, area network bus signal transmission circuit;

[0037] CANH, high-potential pin;

[0038] CANL, low-potential pin. Detailed Implementation

[0039] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the present invention are shown in the accompanying drawings, not all of them.

[0040] This invention defines certain directional terms. Unless otherwise stated, the directional terms used, such as "up," "down," "left," "right," "inner," and "outer," are used for ease of understanding and therefore do not constitute a limitation on the scope of protection of this invention.

[0041] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0042] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0043] Please refer to Figure 1 This embodiment provides an anti-static protection circuit structure (hereinafter referred to as "protection circuit structure") 100 for the network signal bus of an electronic control unit, including an anti-static protection circuit 1 for a Control Area Network Bus (CAN Bus) (hereinafter referred to as "CAN Bus protection circuit") and an anti-static protection circuit 2 for a Local Interconnect Network Bus (LIN Bus) (hereinafter referred to as "LIN Bus protection circuit").

[0044] The CAN Bus protection circuit 1 is electrically connected to the Electronic Control Unit (ECU) 300 via the CAN Bus transceiver 200. The CAN Bus protection circuit 1 includes a common-mode inductor 11, a first transient voltage suppressor (TVS) diode 12, a high-voltage level protection branch circuit HVP, and a low-voltage level protection branch circuit LVP. The LIN Bus protection circuit 2 is electrically connected to the LIN Bus signal transmission circuit LB. The LIN Bus protection circuit 2 includes a second transient voltage suppressor diode 21. The LIN Bus signal transmission circuit LB is electrically connected to the ECU 300 via the LIN Bus signal input terminal 400 and the LIN Bus transceiver 500.

[0045] Please continue to refer to this. Figure 1 and Figure 2 Since the CAN Bus signal is a differential signal, the CAN Bus transceiver 200 includes a high-level pin CANH and a low-level pin CANL.

[0046] In this embodiment, the high-voltage level protection branch circuit HVP is formed by sequentially connecting the high-potential pin CANH of the CAN Bus transceiver 200 to the common-mode inductor 11 and the first TVS diode 12, and then grounding. Similarly, the low-voltage level protection branch circuit LVP is formed by sequentially connecting the low-potential pin CANL of the CAN Bus transceiver 200 to the common-mode inductor 11 and the first TVS diode 12, and then grounding.

[0047] Preferably, the CAN Bus transceiver 200 in this embodiment can be a TAJ1040 chip. The first TVS diode 12 can withstand an air discharge voltage and a contact discharge voltage of 30kV. The common-mode inductor 11 is an ACT45B series common-mode inductor.

[0048] Please refer to the following: Figure 1 and Figure 3 The LIN Bus transceiver 500 includes LIN Bus signal pins (i.e., Figure 3 The LIN pins are internally marked in component 500, and the LIN Bus signal transmission pins are also marked. Figure 3The TXD pin (internal markings) of component 500 and the LIN Bus signal receiving pin (i.e. Figure 3 The RXD pin is marked inside component 500. The LIN Bus signal transmission circuit LB is electrically connected from the LIN Bus signal input terminal 400 to the LIN Bus signal transceiver 500 via the LIN Bus signal pin, and then electrically connected to the ECU 300 via the LIN Bus signal transmit pin and the LIN Bus signal receive pin respectively.

[0049] One end of the second TVS diode 21 is electrically connected between the LIN Bus signal input terminal 400 and the LIN Bus signal transceiver 500, and the other end of the second TVS diode 21 is grounded. Preferably, the LIN Bus signal transceiver 500 can be a TAJ1027 chip, and the air discharge voltage and contact discharge voltage that the second TVS diode 21 can withstand are 15kV and 8kV, respectively.

[0050] Due to the stability of CAN Bus signal transmission when subjected to electrostatic interference or impact, especially with high-potential CANH and low-potential CANL pins, and the LIN Bus signal pins (i.e.... Figure 3 The stability of the LIN Bus signal transmission when the LIN pins (internally marked with LIN) in the middle component 500 are subjected to electrostatic interference or impact determines the overall anti-static capability of the ECU 300's network signal bus.

[0051] Furthermore, according to the ISO 10605 test specification, during ECU 300 operation, static electricity ranging from 4kV to 8kV is released via contact discharge at the gaps between the high-potential CANH pin, the low-potential CANL pin, the LIN Bus signal pins, and the housing, and via air discharge ranging from 4kV to 25kV. Therefore, direct or indirect electrical connections to the protection circuit at these points are necessary to provide direct and effective protection. By employing these methods, the electrostatic discharge tolerance of the network signal bus (including CAN Bus and LIN Bus) can be significantly improved, protecting related components (such as ECU 300, CAN Bus transceiver 200, and LIN Bus transceiver 500) and making them less prone to damage.

[0052] In summary, by using the above methods, the electrostatic discharge (ESD) tolerance of network signal buses (including CAN Bus and LIN Bus) can be significantly improved, protecting related devices (such as ECU 300, CAN Bus transceiver 200, and LIN Bus transceiver 500) from damage.

[0053] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit its implementation. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. An electrostatic protection circuit structure for a network signal bus of an electronic control unit, characterized by, Comprising: a control local area network bus anti-static protection circuit (1) electrically connected with an electronic control unit (300) through a control local area network bus signal transceiver (200), the control local area network bus anti-static protection circuit (1) comprising a high voltage level protection branch circuit (HVP) and a low voltage level protection branch circuit (LVP), the high voltage level protection branch circuit (HVP) being electrically connected in sequence to a common mode inductor (11) and a first transient voltage suppression diode (12) grounded after the common mode inductor (11) and the first transient voltage suppression diode (12) through a high voltage pin (CANH) of the control local area network bus signal transceiver (200), the low voltage level protection branch circuit (LVP) being electrically connected in sequence to the common mode inductor (11) and the first transient voltage suppression diode (12) grounded after the common mode inductor (11) and the first transient voltage suppression diode (12) through a low voltage pin (CANL) of the control local area network bus signal transceiver (200); and a local area network bus anti-static protection circuit (2) electrically connected with a local area network bus signal transmission circuit (LB), the local area network bus signal transmission circuit (LB) being electrically connected in sequence from a local area network bus signal input end (400) to the electronic control unit (300) via a local area network bus signal transceiver (500), the local area network bus anti-static protection circuit (2) comprising a second transient voltage suppression diode (21), one end of the second transient voltage suppression diode (21) being electrically connected between the local area network bus signal input end (400) and the local area network bus signal transceiver (500), the other end of the second transient voltage suppression diode (21) being grounded. The control local area network bus signal transceiver (200) is a TAJ1040 chip.

2. The antistatic protection circuit structure for a network signal bus of an electronic control unit according to claim 1, characterized in that, The local area network bus signal transceiver (500) is a TAJ1027 chip.

3. The antistatic protection circuit structure for a network signal bus of an electronic control unit according to claim 1, characterized in that, The second transient voltage suppression diode (21) can withstand an air discharge voltage and a contact discharge voltage of 30 kV.

4. The electrostatic protection circuit structure for a network signal bus of an electronic control unit according to claim 1, characterized by, The second transient voltage suppression diode (21) can withstand an air discharge voltage and a contact discharge voltage of 15 kV and 8 kV, respectively.

5. The electrostatic protection circuit structure for a network signal bus of an electronic control unit according to claim 1, characterized by, The common mode inductor (11) is a common mode inductor of ACT45B series.

6. The electrostatic protection circuit structure for a network signal bus of an electronic control unit according to claim 1, characterized by, ​

Images