LIN bus driving circuit, LIN node, LIN bus system and vehicle
By introducing a collaborative design of switching modules, voltage divider modules, isolation modules, and comparator modules into the LIN bus system, the problems of signal distortion and inconsistent logic levels in complex environments of the LIN bus system are solved, thereby improving the stability and reliability of the system.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- AVATR CO LTD
- Filing Date
- 2025-04-22
- Publication Date
- 2026-05-26
Smart Images
Figure CN224289813U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the fields of integrated circuit technology and LIN bus technology, and particularly to a LIN bus driver circuit, a LIN node, a LIN bus system, and a vehicle. Background Technology
[0002] Local Interconnect Network (LIN) is a low-cost, single-wire serial communication network. In vehicle development, the LIN bus connects the communication between various controllers and sensors. The communication path is long, and the vehicle's working environment is complex and full of interference sources, which can easily lead to LIN bus signal distortion and inconsistent logic level transmission and reception, resulting in poor stability of the LIN bus system. Utility Model Content
[0003] Therefore, embodiments of this application provide a LIN bus driver circuit, a LIN node, a LIN bus system, and a vehicle, which can isolate the LIN node and the LIN bus, thereby improving the stability and reliability of the LIN bus system.
[0004] To achieve the above objectives, the technical solution of this application embodiment is implemented as follows:
[0005] In a first aspect, embodiments of this application provide a LIN bus driver circuit, including: a switching module, a voltage divider module, an isolation module, and a comparator module; a first terminal of the switching module is connected to the data transmitting terminal of the microcontroller, and a second terminal of the switching module is connected to the first terminal of the voltage divider module; a second terminal of the voltage divider module is connected to the LIN bus, and a third terminal of the voltage divider module is connected to the input terminal of the isolation module; the output terminal of the isolation module is connected to the input terminal of the comparator module; and the output terminal of the comparator module is connected to the data receiving terminal of the microcontroller.
[0006] Secondly, embodiments of this application provide a LIN node, including: a microcontroller and the aforementioned LIN bus driver circuit; the data transmitting end of the microcontroller is connected to the first end of the switching module in the LIN bus driver circuit; the data receiving end of the microcontroller is connected to the output end of the comparison module in the LIN bus driver circuit.
[0007] Thirdly, embodiments of this application provide a LIN bus system, including: a LIN bus and a plurality of LIN nodes as described above; the plurality of LIN nodes are serially connected to the LIN bus.
[0008] Fourthly, embodiments of this application provide a vehicle including the aforementioned LIN bus system.
[0009] The LIN bus driver circuit, LIN node, LIN bus system, and vehicle provided in this application embodiment, in the LIN bus driver circuit, through a switching module and a voltage divider module, convert the logic level signal output to the data transmitting end into the LIN bus bus level and provide input voltage to the isolation module. The high input impedance and low output impedance of the isolation module can isolate the preceding and following circuits. The comparator module can convert the voltage output by the isolation module into the level signal received by the data receiving end. Through the coordinated action of the switching module, voltage divider module, isolation module, and comparator module, it is ensured that the logic level signal sent by the data receiving end is consistent with the logic level signal received by the data input end. Furthermore, the high input impedance and low output impedance of the isolation module can isolate the preceding and following circuits, reduce interference caused by changes in application load, and improve the stability and reliability of the LIN bus system. Attached Figure Description
[0010] Figure 1 A schematic diagram of the LIN bus driver circuit provided in the embodiments of this application. Figure 1 ;
[0011] Figure 2 Schematic diagram of the switching module provided in the embodiments of this application Figure 1 ;
[0012] Figure 3 This is a schematic diagram of the structure of the inverting unit provided in an embodiment of this application;
[0013] Figure 4 Schematic diagram of the switching module provided in the embodiments of this application Figure 2 ;
[0014] Figure 5 This is a schematic diagram of the voltage divider module provided in an embodiment of this application;
[0015] Figure 6 This is a schematic diagram of the structure of the isolation module provided in an embodiment of this application;
[0016] Figure 7 A schematic diagram of the structure of the comparison module provided in an embodiment of this application;
[0017] Figure 8 A schematic diagram of the LIN bus driver circuit provided in the embodiments of this application. Figure 2 ;
[0018] Figure 9 A schematic diagram of the LIN bus driver circuit provided in the embodiments of this application. Figure 3 ;
[0019] Figure 10 This is a schematic diagram of the LIN bus system provided in an embodiment of this application.
[0020] Figure label:
[0021] 110: Switching module; 120: Voltage divider module; 130: Isolation module; 140: Comparator module; 210: Inverting unit; 220: Switching unit; 710: Voltage divider unit; R1: First resistor; R2: Second resistor; R3: Third resistor; R4: Fourth resistor; R5: Fifth resistor; R6: Sixth resistor; R7: Seventh resistor; R8: Eighth resistor; R9: Ninth resistor; U: Inverter; Q: Field-effect transistor; D: Diode; C: Capacitor; A1: First operational amplifier; A2: Second operational amplifier; 1010: LIN bus; 1020: Master node; 1030: Slave node. Detailed Implementation
[0022] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the specific technical solutions of this application will be further described in detail below with reference to the accompanying drawings of the embodiments of this application. The following embodiments are used to illustrate this application, but are not intended to limit the scope of this application.
[0023] In the embodiments of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the embodiments of this application, unless otherwise stated, "multiple" means two or more.
[0024] Furthermore, in the embodiments of this application, directional terms such as "upper," "lower," "left," and "right" are defined relative to the positions in which the components are schematically placed in the accompanying drawings. It should be understood that these directional terms are relative concepts, used for relative description and clarification, and can change accordingly depending on the position of the components in the accompanying drawings.
[0025] In the embodiments of this application, unless otherwise explicitly specified and limited, the term "connection" should be interpreted broadly. For example, "connection" can mean a fixed connection, a detachable connection, or an integral part; it can mean a direct connection or an indirect connection through an intermediate medium.
[0026] In embodiments of this application, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.
[0027] In the embodiments of this application, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design that is described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design. Specifically, the use of the terms "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.
[0028] It should be understood that, in the following description, "circuit" refers to a conductive loop consisting of at least one element or sub-circuit connected by an electrical or electromagnetic link. When an element or circuit is said to be "connected" to another element or "connected" between two nodes, it can be directly coupled or connected to the other element, or there may be intermediate elements. The connection between elements can be physical, logical, or a combination thereof. Conversely, when an element is said to be "directly coupled to" or "directly connected" to another element, it means that there are no intermediate elements between them.
[0029] This application provides a LIN bus driver circuit, a LIN node, a LIN bus system, and a vehicle. It should be noted that the LIN bus (Local Interconnect Network) is a local interconnect network that links the communication between various controllers and sensors in the overall vehicle development.
[0030] The LIN bus driver circuit in this application is used to convert logic level signals (0 or 1) into physical levels (dominant or recessive levels) of the LIN bus in the transmitting direction, and to convert physical levels of the LIN bus into logic level signals in the receiving direction. It can also provide sufficient current to drive the LIN bus. The LIN node in this application includes the LIN bus driver circuit and a microcontroller.
[0031] The LIN bus system in this application includes: a LIN bus and LIN nodes. The LIN nodes include master nodes and slave nodes. The master node is responsible for scheduling communication, and the slave nodes respond to the commands of the master node. The LIN node includes: a microcontroller and a LIN bus driver circuit. The microcontroller is used to run the control program and control the application load. The application load can be a sensor or an actuator. For example, in the LIN bus system of a vehicle, the application load can be a door, seat, air conditioning, lighting system, etc.
[0032] The term "vehicle" in this application can refer to large vehicles, small vehicles, special-purpose vehicles, etc. For example, according to vehicle type, the vehicle in this application can be a sedan, an off-road vehicle, a multi-purpose vehicle (MPV), or other types of vehicles. Generally, a vehicle is equipped with wheels, a power source, and a transmission system between the wheels and the power source. The transmission system transmits the power provided by the power source to the wheels, causing the wheels to rotate and thus driving the vehicle.
[0033] It should be noted that the type of power source of the vehicle is not limited in the embodiments of this application. For example, for fuel vehicles, the power source can refer to fuel engines such as gasoline engines and diesel engines; for electric vehicles, the power source can refer to electric motors; for hybrid vehicles, the power source can refer to engines or electric motors; for vehicles powered by other means, the power source can refer to devices that generate power.
[0034] In vehicle development, the LIN bus connects the communication between various controllers and sensors. However, the communication path is long, and the vehicle's working environment is complex and full of interference sources, which may lead to problems such as LIN bus signal distortion and inconsistent logic levels. Improving the anti-interference capability of the LIN bus system is a core requirement. The LIN bus driver circuit provided in this application isolates the front and rear stage circuits from the perspective of hardware circuit design, reduces the impact of application load changes on LIN nodes and LIN bus, ensures the consistency of LIN node transmission and reception logic and the stability of LIN bus levels, and improves the stability and reliability of the LIN bus system.
[0035] Reference Figure 1 This application provides a LIN bus driver circuit, including: a switch module 110, a voltage divider module 120, an isolation module 130, and a comparator module 140;
[0036] The first terminal of the switch module 110 is connected to the data transmission terminal of the microcontroller, and the second terminal of the switch module 110 is connected to the first terminal of the voltage divider module 120.
[0037] The second terminal of the voltage divider module 120 is connected to the LIN bus, and the third terminal of the voltage divider module 120 is connected to the input terminal of the isolation module 130.
[0038] The output of isolation module 130 is connected to the input of comparison module 140;
[0039] The output of the comparator module 140 is connected to the data receiver of the microcontroller.
[0040] Among them, the microcontroller unit (MCU) is used to run the control program; when the LIN node is the master node, the microcontroller of the master node runs the LIN protocol and upper-layer control logic; when the LIN node is the slave node, the microcontroller of the slave node is used to parse the master node's instructions and control the local application load.
[0041] For example, the application load is the window motor; the master node sends a window raising command to the slave node, and the MCU of the slave node outputs a control signal to the window motor according to the window raising command, driving the window motor to perform the action of raising the window.
[0042] The microcontroller has a data transmitter (TXD, Transmit Data), which can send logic level signals 1 or 0; and a data receiver (RXD, Receive Data), which can receive logic level signals. When the TXD sends a logic level signal, the actual transmitted signal is fed back to the RXD through the LIN bus driver circuit to confirm whether the microcontroller's transmission and reception are consistent.
[0043] The switch module 110 and the voltage divider module 120 work together to achieve level conversion, that is, to convert the logic level signal of TXD into the bus level of the LIN bus.
[0044] When the logic level signal of TXD is 0, the LIN bus is pulled to the dominant level through the switch module 110 and the voltage divider module 120. When the logic level signal of TXD is 1, the LIN bus is pulled to the recessive level through the switch module 110 and the voltage divider module 120.
[0045] The switching module 110 and the voltage divider module 120 work together to provide input voltage to the isolation module 130. When the bus level of the LIN bus is dominant, the voltage divider module 120 divides the voltage, making the input of the isolation module 130 low. When the bus level of the LIN bus is recessive, the voltage divider module 120 divides the voltage, making the input of the isolation module 130 high.
[0046] The isolation module 130 has a very high input impedance, which makes its impact on the preceding circuit small, almost like an open circuit. This high impedance characteristic helps protect the preceding circuit and prevent signal loss. The isolation module 130 has a very low output impedance, which makes its impact on the following circuit small. Regardless of the impedance of the following circuit, a large voltage can be obtained, maintaining the stability of the output voltage of the isolation module 130.
[0047] The high input impedance and low output impedance of the isolation module 130 can isolate the preceding and following circuits, reduce interference caused by changes in application load, and improve the stability and reliability of the LIN bus system.
[0048] The comparison module 140 is used to compare the voltage magnitudes of the two input terminals to determine the output level signal. The output level signal is either 1 or 0. The output terminal of the comparison module 140 is connected to the RXD of the MCU. In other words, the level signal output by the comparison module 140 is the level signal received by the RXD. When the output terminal of the isolation circuit is at a low voltage, the comparison module 140 can output a level signal of 0. When the output terminal of the isolation circuit is at a high voltage, the comparison module 140 can output a level signal of 1.
[0049] Through the coordinated action of isolation module 130 and comparison module 140, it can be ensured that when the LIN bus is at a dominant level, the level signal received by RXD is 0, and when the LIN bus is at a recessive level, the level signal received by RXD is 1.
[0050] The LIN bus driver circuit provided in this application includes: a switch module 110, a voltage divider module 120, an isolation module 130, and a comparator module 140; the first terminal of the switch module 110 is connected to the data transmitting terminal of the microcontroller, the second terminal of the switch module 110 is connected to the first terminal of the voltage divider module 120; the second terminal of the voltage divider module 120 is connected to the LIN bus, and the third terminal of the voltage divider module 120 is connected to the input terminal of the isolation module 130; the output terminal of the isolation module 130 is connected to the input terminal of the comparator module 140; and the output terminal of the comparator module 140 is connected to the data receiving terminal of the microcontroller. The switching module 110 and voltage divider module 120 convert the logic level signal output to the data transmitting end into the bus level of the LIN bus and provide input voltage to the isolation module 130. The high input impedance and low output impedance of the isolation module 130 can isolate the preceding and following circuits. The comparator module 140 can convert the voltage output by the isolation module 130 into the level signal received by the data receiving end. In this embodiment, through the synergistic effect of the switching module 110, voltage divider module 120, isolation module 130 and comparator module 140, the logic level signal sent by the data receiving end is consistent with the logic level signal received by the data input end. Furthermore, the high input impedance and low output impedance of the isolation module 130 can isolate the preceding and following circuits, reduce interference caused by changes in application load, and improve the stability and reliability of the LIN bus system.
[0051] In some embodiments of this application, reference is made to Figure 2 The switching module 110 includes an inverting unit 210 and a switching unit 220; the input terminal of the inverting unit 210 is connected to the data transmission terminal of the microcontroller, and the output terminal of the inverting unit 210 is connected to the first terminal of the switching unit 220; the second terminal of the switching unit 220 is connected to the first terminal of the voltage divider module 120; and the third terminal of the switching unit 220 is grounded.
[0052] In other words, the first terminal of the switching module 110 is the input terminal of the inverting unit 210, and the second terminal of the switching module 110 is the second terminal of the switching unit 220.
[0053] The inverting unit 210 is used to invert the logic level signal of TXD. When the logic level signal of TXD is 1, the output of the inverting unit 210 is 0, and when the logic level signal of TXD is 0, the output of the inverting unit 210 is 1.
[0054] Switching unit 220 is in an ON or OFF state. When switching unit 220 is in an ON state, the LIN bus is pulled to a dominant level. When switching unit 220 is in an OFF state, the LIN bus is pulled to a recessive level.
[0055] Specifically, the switching unit 220 can be a field-effect transistor (FET), the output terminal of the inverting unit 210 is connected to the gate of the FET, the source of the FET is grounded, and the drain of the FET is connected to the first terminal of the voltage divider module 120.
[0056] In some embodiments of this application, reference is made to Figure 3 The inverter unit 210 includes an inverter U and a ninth resistor R9. The input terminal of the inverter U is connected to the data transmission terminal of the microcontroller, and the first terminal of the ninth resistor R9 is connected to the first terminal of the switching unit 220. The second terminal of the ninth resistor R9 is connected to the second power supply.
[0057] The second power supply can be a 5V power supply. That is, the input terminal of inverter U and the first terminal of the ninth resistor R9, i.e., the first terminal of switch module 110, are connected, and the output terminal of inverter U is the output terminal of inverter unit 210.
[0058] In the above embodiment, the second power supply is connected through the ninth resistor R9, so that the default input of the inverter U is high level, thus preventing the inverter U from being floating.
[0059] Reference Figure 4 When the logic level signal of TXD is 0, the logic level signal output by inverter U is 1, and the field-effect transistor Q is in the on state, so that the LIN bus is grounded through the voltage divider module 120 and the third terminal of the field-effect transistor Q, thereby pulling the LIN bus to the dominant level; when the logic level signal of TXD is 1, the logic level signal output by inverter U is 0, and the field-effect transistor Q is in the off state, so that the LIN bus receives a high voltage through the voltage divider module 120, thereby pulling the LIN bus to the recessive level.
[0060] In the above embodiment, the logic level signal of TXD is inverted by the inverting unit 210 to control the on or off state of the switching unit 220, so as to convert the logic level signal of TXD into the bus level of the LIN bus, so that the logic level signal sent by TXD is consistent with the level signal sent to the LIN bus.
[0061] In some embodiments of this application, reference is made to Figure 5 The voltage divider module 120 includes: a first resistor R1, a second resistor R2, and a third resistor R3; the first end of the first resistor R1 is connected to the second end of the switch module 110, the LIN bus, and the first end of the second resistor R2; the second end of the first resistor R1 is connected to the first power supply; the second end of the second resistor R2 is connected to the second end of the first resistor R1 and the input end of the isolation module 130, and the first end of the third resistor R3 is connected; the second end of the third resistor R3 is grounded.
[0062] In other words, in the specific circuit structure of the voltage divider module 120, the first end of the first resistor R1 is the first end of the voltage divider module 120, and the second end of the voltage divider module 120 is connected to the first end of the voltage divider module 120 by a wire. It can be understood that the first end and the second end of the voltage divider module 120 are the same end; the third end of the voltage divider module 120 is the second end of the second resistor R2, which is also the first end of the third resistor R3.
[0063] The first power source can be a power source that provides 12V voltage; the resistance of the first resistor R1 is less than the resistance of the second resistor R2 and also less than the resistance of the third resistor R3.
[0064] When the logic level signal 0 sent by TXD is turned on, the field-effect transistor Q is turned on, and the 12V voltage provided by the first power supply is shorted to ground, that is, the voltage at the first end of the first resistor R1 is 0, and the bus level of the LIN bus is the dominant level; since the third resistor R3 is grounded, the voltage at the input end of the isolation module 130 is 0. After passing through the isolation module 130 and the comparator module 140, the logic level signal received by RXD is 0, thus realizing the logic transmit and receive consistency of the LIN bus driver circuit.
[0065] When TXD sends a logic level signal of 1, the field-effect transistor Q is turned off. The 12V voltage provided by the first power supply is divided by the voltage divider module 120. Since the resistance of the first resistor R1 is small and the resistances of the second resistor R2 and the third resistor R3 are large, the second resistor R2 and the third resistor R3 receive more voltage, while the first resistor R1 receives less voltage. The bus level of the LIN bus is recessive. After the bus voltage is divided by the second resistor R2 and the third resistor R3, a high voltage is output to the input of the isolation module 130. After passing through the isolation module 130 and the comparator module 140, the logic level signal 1 received by RXD is realized, achieving logical transmit and receive consistency of the LIN bus driver circuit.
[0066] For example, the resistance of the first resistor R1 can be 1K ohms, the resistance of the second resistor R2 can be 47K ohms, and the resistance of the third resistor R3 can be 33K ohms. The resistance of the first resistor R1 is much smaller than the resistances of the second resistor R2 and the third resistor R3, so that the bus level of the LIN bus is close to 12V. After the voltage is divided by the second resistor R2 and the third resistor R3, the voltage at the input terminal of the isolation module 130 is 5V.
[0067] Optionally, the voltage divider module 120 further includes at least one of a diode D or a capacitor C, wherein the anode of the diode D is connected to the first power supply, the cathode of the diode D is connected to the second terminal of the first resistor R1, the first terminal of the capacitor C is connected to the first terminal of the first resistor R1, and the second terminal of the capacitor C is grounded.
[0068] Diode D has unidirectional conductivity, which can prevent current backflow, achieve power supply isolation, and protect the safety of the power supply. When the logic level signal output by TXD switches between 0 and 1, capacitor C provides local power for transient current, reducing the impact of power supply noise on the bus level.
[0069] In the above embodiments, the voltage divider module 120 and the switch module 110 work together to convert the logic level signal of TXD into the bus level of the LIN bus, so that the logic level signal emitted by TXD is consistent with the level signal sent to the LIN bus. They can also provide an input voltage to the isolation module 130, so that the logic level signal emitted by TXD is consistent with the logic level signal received by RXD.
[0070] In some embodiments of this application, reference is made to Figure 6 The isolation module 130 includes: a first operational amplifier A1, a fourth resistor R4, and a fifth resistor R5; the first end of the fourth resistor R4 is connected to the third end of the voltage divider module 120, and the second end of the fourth resistor R4 is connected to the non-inverting input of the first operational amplifier A1; the output of the first operational amplifier A1 is connected to the first end of the fifth resistor R5; the inverting input of the first operational amplifier A1 is connected to the second end of the fifth resistor R5; and the second end of the fifth resistor R5 is connected to the input of the comparator module 140.
[0071] The resistance values of the fourth resistor R4 and the fifth resistor R5 can be set based on experience; no limit is placed on their resistance values here.
[0072] It should be noted that the input resistance of the inverting input of the first operational amplifier A1 approaches infinity. Connecting the inverting input to the output effectively short-circuits the feedback circuit, resulting in a gain of 1. This means the input voltage of the isolation module 130 equals the output voltage. Because the non-inverting input of the first operational amplifier A1 has a very high impedance, its impact on the preceding circuit is minimal, almost negligible. This high impedance characteristic helps protect the preceding circuit and prevent signal loss. Furthermore, the very low output impedance of the first operational amplifier A1 means it has minimal impact on the following circuit, is unaffected by the impedance of the following stage, and maintains output voltage stability. These high input and low output impedance characteristics effectively isolate the preceding and following circuits, reducing interference caused by changes in application load and improving the stability and reliability of the LIN bus system.
[0073] In some embodiments of this application, reference is made to Figure 7The comparison module 140 includes: a second operational amplifier A2, a sixth resistor R6, and a voltage divider unit 710; the first end of the sixth resistor R6 is connected to the non-inverting input of the second operational amplifier A2 and the output of the isolation module 130, and the second end of the sixth resistor R6 is connected to the second power supply; the inverting input of the second operational amplifier A2 is connected to the first end of the voltage divider unit 710; and the output of the second operational amplifier A2 is connected to the data receiving terminal of the microcontroller.
[0074] The first end of the sixth resistor R6 is connected to the non-inverting input of the second operational amplifier A2, and the second end of the sixth resistor R6 is connected to the second power supply, so that the non-inverting input of the second operational amplifier A2 is at a default high level to prevent it from being floating.
[0075] In some embodiments of this application, reference is made to Figure 7 The voltage divider unit 710 includes a seventh resistor R7 and an eighth resistor R8; the first end of the seventh resistor R7 is connected to the inverting input of the second operational amplifier A2 and the first end of the eighth resistor R8, and the second end of the seventh resistor R7 is grounded; the second end of the eighth resistor R8 is connected to the second power supply.
[0076] In this embodiment, the resistance values of the seventh resistor R7 and the eighth resistor R8 are equal. Since the second power supply provides a 5V voltage, the voltage at the inverting input terminal of the second operational amplifier A2 is 2.5V. The resistance values of the seventh resistor R7 and the eighth resistor R8 can be set according to actual conditions. This embodiment does not limit the resistance values of the seventh resistor R7 and the eighth resistor R8.
[0077] For example, the LIN bus driver circuit is as follows Figure 8 As shown, when the logic level signal of TXD is 1, the logic level signal is processed by inverter U, and the output logic level signal of inverter U is 0, causing the field-effect transistor Q to be cut off. The current flow is as follows. Figure 8 As shown by the dashed line, the 12V voltage is divided by the voltage divider module 120, making the voltage at the input terminal of the isolation module 130 5V, that is, the voltage at the first terminal of the fourth resistor R4 is 5V, and thus the voltage at the non-inverting input terminal of the second operational amplifier A2 is 5V. Since the voltage at the inverting input terminal of the second operational amplifier A2 is 2.5V, the second operational amplifier A2 outputs a level signal of 1.
[0078] Reference Figure 9 When the logic level signal of TXD is 0, the logic level signal is processed by inverter U, and the output logic level signal of inverter U is 1, causing the switching unit 220 to be cut off, and the 12V voltage to be shorted to ground. The current flow is as follows. Figure 9As shown by the dashed line, the on-state voltage drop of the field-effect transistor Q is 0.7V, therefore the drain voltage of the field-effect transistor Q is 0.7V. After being divided by the voltage divider module 120, the voltage at the input terminal of the isolation module 130 is 0.3V, that is, the voltage at the first terminal of the fourth resistor R4 is 0.3V. Consequently, the voltage at the non-inverting input terminal of the second operational amplifier A2 is 0.3V. Since the voltage at the inverting input terminal of the second operational amplifier A2 is 2.5V, the output level signal of the second operational amplifier A2 is 0.
[0079] Therefore, it can be seen that by converting the output voltage of the isolation module 130 into a level signal through the comparison module 140, and by setting the voltage divider unit 710, the logic level signal sent by TXD is ensured to be consistent with the logic level signal received by RXD.
[0080] In this embodiment, the switching module 110 and voltage divider module 120 convert the logic level signal output to the data transmitting end into the bus level of the LIN bus and provide input voltage to the isolation module 130. The high input impedance and low output impedance of the isolation module 130 can isolate the preceding and following circuits. The comparator module 140 can convert the voltage output by the isolation module 130 into the level signal received by the data receiving end. In this embodiment, through the synergistic effect of the switching module 110, voltage divider module 120, isolation module 130 and comparator module 140, the logic level signal sent by the data receiving end is consistent with the logic level signal received by the data input end. Furthermore, the high input impedance and low output impedance of the isolation module 130 can isolate the preceding and following circuits, reduce interference caused by changes in application load, and improve the stability and reliability of the LIN bus system.
[0081] This application also provides a LIN node, including: a microcontroller and the LIN bus driver circuit mentioned in all the above embodiments; the data transmitting end of the microcontroller is connected to the first end of the switching module 110 in the LIN bus driver circuit; the data receiving end of the microcontroller is connected to the output end of the comparison module 140 in the LIN bus driver circuit.
[0082] For a detailed description of the LIN bus driver circuit, please refer to the description in the above embodiments.
[0083] The LIN node provided in this application includes a microcontroller and a LIN bus driver circuit. The LIN bus driver circuit converts the logic level signal output to the data transmitting end into the bus level of the LIN bus through a switching module and a voltage divider module, and provides an input voltage to the isolation module. The high input impedance and low output impedance of the isolation module can isolate the preceding and following circuits. The comparator module can convert the voltage output by the isolation module into a level signal received by the data receiving end. Through the synergistic effect of the switching module, voltage divider module, isolation module and comparator module, this application ensures that the logic level signal sent by the data receiving end is consistent with the logic level signal received by the data input end. Furthermore, the high input impedance and low output impedance of the isolation module can isolate the preceding and following circuits, reduce interference caused by changes in application load, and improve the stability and reliability of the LIN bus system.
[0084] This application also provides a LIN bus system, see reference. Figure 10 It includes: a LIN bus 1010 and multiple LIN nodes. The multiple LIN nodes are serially connected to the LIN bus 1010.
[0085] The LIN nodes include master node 1020 and slave node 1030.
[0086] The microcontroller is used to run control programs to control application loads, which can be sensors or actuators. For example, in a vehicle's LIN bus system, application loads can be doors, seats, air conditioning, lighting systems, etc.
[0087] The LIN node includes: a microcontroller and the LIN bus driver circuit mentioned in all the above embodiments; the data transmitting end of the microcontroller is connected to the first end of the switching module 110 in the LIN bus driver circuit; the data receiving end of the microcontroller is connected to the output end of the comparison module 140 in the LIN bus driver circuit.
[0088] For a detailed description of the LIN bus driver circuit, please refer to the description in the above embodiments.
[0089] LIN bus driver circuit; the data transmitting end of the microcontroller is connected to the first terminal of the switching module 110 in the LIN bus driver circuit; the data receiving end of the microcontroller is connected to the output terminal of the comparison module 140 in the LIN bus driver circuit.
[0090] The LIN bus system provided in this application includes a LIN bus and multiple LIN nodes. Each LIN node includes a microcontroller and a LIN bus driver circuit. The LIN bus driver circuit converts the logic level signal output to the data transmitting end into the bus level of the LIN bus through a switching module and a voltage divider module, and provides an input voltage to the isolation module. The high input impedance and low output impedance of the isolation module can isolate the preceding and following circuits. The comparator module can convert the voltage output by the isolation module into a level signal received by the data receiving end. Through the synergistic effect of the switching module, voltage divider module, isolation module, and comparator module, this application ensures that the logic level signal sent by the data receiving end is consistent with the logic level signal received by the data input end. Furthermore, the high input impedance and low output impedance of the isolation module can isolate the preceding and following circuits, reduce interference caused by changes in application load, and improve the stability and reliability of the LIN bus system.
[0091] This application also provides a vehicle, including a LIN bus system.
[0092] The LIN bus system includes a LIN bus and multiple LIN nodes. The multiple LIN nodes are serially connected to the LIN bus; each LIN node includes a microcontroller and the LIN bus driver circuitry mentioned in all the above embodiments.
[0093] The sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments. The above are merely preferred embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made based on the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.
Claims
1. A LIN bus drive circuit, characterized by, include: Switching module, voltage divider module, isolation module, and comparator module; The first terminal of the switch module is connected to the data transmission terminal of the microcontroller, and the second terminal of the switch module is connected to the first terminal of the voltage divider module. The second terminal of the voltage divider module is connected to the LIN bus, and the third terminal of the voltage divider module is connected to the input terminal of the isolation module. The output of the isolation module is connected to the input of the comparison module; The output of the comparison module is connected to the data receiving end of the microcontroller.
2. The circuit according to claim 1, characterized in that, The voltage divider module includes: a first resistor, a second resistor, and a third resistor; The first terminal of the first resistor is connected to the second terminal of the switching module, the LIN bus, and the first terminal of the second resistor; the second terminal of the first resistor is connected to the first power supply. The second end of the second resistor is connected to the input terminal of the isolation module and the first end of the third resistor; The second terminal of the third resistor is grounded.
3. The circuit according to claim 1, characterized in that, The isolation module includes: a first operational amplifier, a fourth resistor, and a fifth resistor; The first end of the fourth resistor is connected to the third end of the voltage divider module, and the second end of the fourth resistor is connected to the non-inverting input of the first operational amplifier. The output terminal of the first operational amplifier is connected to the first terminal of the fifth resistor; The inverting input terminal of the first operational amplifier is connected to the second terminal of the fifth resistor; The second end of the fifth resistor is connected to the input terminal of the comparison module.
4. The circuit according to claim 1, characterized in that, The comparison module includes: a second operational amplifier, a sixth resistor, and a voltage divider unit; The first end of the sixth resistor is connected to the non-inverting input terminal of the second operational amplifier and the output terminal of the isolation module, and the second end of the sixth resistor is connected to the second power supply. The inverting input terminal of the second operational amplifier is connected to the first terminal of the voltage divider unit; The output of the second operational amplifier is connected to the data receiver of the microcontroller.
5. The circuit according to claim 4, characterized in that, The voltage divider unit includes: a seventh resistor and an eighth resistor; The first end of the seventh resistor is connected to the inverting input terminal of the second operational amplifier and the first end of the eighth resistor, and the second end of the seventh resistor is grounded. The second end of the eighth resistor is connected to the second power supply.
6. The circuit according to any one of claims 1 to 5, characterized in that, The switching module includes: an inverting unit and a switching unit; The input terminal of the inverting unit is connected to the data transmission terminal of the microcontroller, and the output terminal of the inverting unit is connected to the first terminal of the switching unit. The second end of the switching unit is connected to the first end of the voltage divider module; The third terminal of the switching unit is grounded.
7. The circuit according to claim 6, characterized in that, The inverting unit includes an inverter and a ninth resistor; The input terminal of the inverter is connected to the data transmission terminal of the microcontroller and the first terminal of the ninth resistor; the output terminal of the inverter is connected to the first terminal of the switching unit. The second end of the ninth resistor is connected to the second power supply.
8. A LIN node, characterized in that, include: The microcontroller and the LIN bus driver circuit as described in any one of claims 1-7; The data transmitting end of the microcontroller is connected to the first terminal of the switching module in the LIN bus driver circuit; the data receiving end of the microcontroller is connected to the output terminal of the comparison module in the LIN bus driver circuit.
9. A LIN bus system, characterized in that, include: A LIN bus and a plurality of LIN nodes as described in claim 8; the plurality of LIN nodes are serially connected to the LIN bus.
10. A vehicle, characterized in that, include: The LIN bus system as described in claim 9.