Vehicle-mounted LIN network transceiver circuit, communication apparatus, and vehicle unit system

Abstract

Embodiments of the present application relate to the technical field of automobile electronics, and specifically relate to a vehicle-mounted LIN network transceiver circuit, a communication apparatus, and a vehicle unit system. In the vehicle-mounted LIN network transceiver circuit of the present application, an enable circuit, an output circuit, an input circuit, and a protection circuit are provided, and the enable circuit, the output circuit, the input circuit, and the protection circuit are connected between a microcontroller unit and a LIN bus, so that not only are LIN signal transmission and reception achieved, but also the output circuit and the protection circuit are connected to the LIN bus to perform overcurrent protection for an electrical signal transmitted from the LIN bus, thereby preventing damage to a device and a failure to achieve LIN communication. By means of the enable circuit, low current consumption of the circuit is achieved, to meet static current requirements in a vehicle-mounted product.

Description

In-vehicle LIN network transceiver circuit, communication device and vehicle infotainment system

[0001] This application claims priority to Chinese patent application filed on August 28, 2024, with application number 202411190550.4 and title "Vehicle-mounted LIN network transceiver circuit, communication device and vehicle system", the entire contents of which are incorporated herein by reference. Technical Field

[0002] The embodiments of the present invention relate to the field of automotive electronics technology, specifically to in-vehicle LIN network transceiver circuits, communication devices, and vehicle infotainment systems. Background Technology

[0003] The goal of LIN (Local Interconnect Network) is to provide auxiliary functions for existing automotive networks, such as the CAN bus. Therefore, the LIN bus is an auxiliary bus network. In situations where the bandwidth and versatility of the CAN bus are not required, such as communication between smart sensors and braking systems, using the LIN bus can significantly reduce costs.

[0004] In addition to defining the basic protocol and physical layer, the LIN technical specification also defines development tools and application software interfaces. LIN communication is based on the SCI (UART) data format, employs a single master controller / multiple slave device mode, uses only a single 12V signal bus, and a node synchronization clock line without a fixed time base. This low-cost serial communication mode and corresponding development environment have been standardized by the LIN Association. LIN standardization will reduce costs for automakers and suppliers in research and development, applications, and operating systems.

[0005] In-vehicle LIN networks mostly use dedicated automotive-grade LIN transceiver chips for communication, which are more expensive. Furthermore, the integrated chips are usually packaged in SO8, and the peripheral circuits result in a larger circuit board area, which is not advantageous for miniaturized product designs. Summary of the Invention

[0006] In view of the above problems, embodiments of the present invention provide an in-vehicle LIN network transceiver circuit, a communication device, and an in-vehicle infotainment system, which solves the problems of high cost and large size of automotive-grade LIN transceiver chips.

[0007] In a first aspect, the present invention provides an in-vehicle LIN network transceiver circuit, applied in a microcontroller having an enable signal terminal, a LIN output terminal, a LIN input terminal, and a power supply output terminal. The circuit includes an enable circuit, an output circuit, an input circuit, and a protection circuit.

[0008] The enabling circuit is connected to the enabling signal terminal, and the enabling circuit is connected to the LIN communication interface through the protection circuit to control the level signal of the LIN communication interface.

[0009] The output circuit is connected to the LIN output terminal and the LIN communication interface. The output circuit is used to output the microcontroller's LIN to the LIN communication interface.

[0010] The input circuit is connected to the LIN input terminal and the LIN communication interface, and the input circuit is used to output the LIN signal of the LIN communication interface to the microcontroller.

[0011] In some alternative embodiments, the enabling circuit includes a second transistor, a sixth resistor, an eighth resistor, and a fifth transistor;

[0012] The base of the second transistor is connected to the enable signal terminal, the collector is connected to the base of the fifth transistor through the sixth resistor, and the emitter is grounded;

[0013] The emitter of the fifth transistor is connected to the power supply of the battery, and the collector is connected to the LIN communication interface through a protection circuit.

[0014] One end of the eighth resistor is connected to the base of the fifth transistor, and the other end is connected to the emitter of the fifth transistor.

[0015] In some optional embodiments, the protection circuit includes a first diode, a ninth resistor, and a first capacitor;

[0016] The cathode of the first diode is connected to the collector of the fifth transistor, and the anode of the first diode is connected to the LIN communication interface through the ninth resistor; one end of the first capacitor is connected to the LIN communication interface and the other end is grounded.

[0017] In some optional embodiments, the output circuit includes a first resistor, a second resistor, a third diode, a fourth diode, and a seventh resistor;

[0018] One end of the first resistor is connected to the output terminal of the LIN transistor, and the other end is connected to the second resistor, the collector of the third transistor, the base of the fourth transistor, and the power supply output terminal.

[0019] The collector of the fourth transistor is connected to the LIN communication, and the emitter is connected to the base of the third transistor and the seventh resistor.

[0020] The emitter of the third transistor, the other end of the second resistor, and the other end of the seventh resistor are grounded.

[0021] In some optional embodiments, the output circuit includes a first resistor, a second resistor, a first transistor, a third resistor, a fifth resistor, a third diode, a fourth diode, and a seventh resistor;

[0022] One end of the first resistor is connected to the LIN output terminal, and the other end is connected to the second resistor and the base of the first transistor.

[0023] The collector of the first transistor is connected to the third resistor, the fifth resistor, the collector of the third transistor, and the base of the fourth transistor, while the emitter is grounded.

[0024] The collector of the fourth transistor is connected to the LIN communication, and the emitter is connected to the base of the third transistor and the seventh resistor.

[0025] The other end of the third resistor is connected to the power supply output terminal, and the emitter of the third transistor, the other end of the second resistor, the other end of the fifth resistor, and the other end of the seventh resistor are grounded.

[0026] In some alternative embodiments, the first transistor, second transistor, third transistor, fourth transistor, and fifth transistor are replaced with MOSFETs.

[0027] In some alternative embodiments, the input circuit includes a voltage detector, a tenth resistor, an eleventh resistor, a second capacitor, and a fourth resistor;

[0028] The voltage detector is provided with a detection input terminal and a detection output terminal. The detection input terminal is connected to the tenth resistor, the eleventh resistor, and the second capacitor. The other end of the tenth resistor is connected to the LIN communication interface, and the other ends of the eleventh resistor and the second capacitor are grounded.

[0029] The detection output terminal is connected to the LIN input terminal and the fourth resistor, and the other end of the fourth resistor is connected to the power supply output terminal.

[0030] In some alternative embodiments, the input circuit includes a voltage comparator, a tenth resistor, an eleventh resistor, a second capacitor, and a fourth resistor;

[0031] The non-inverting input of the voltage comparator is connected to the tenth resistor, the eleventh resistor, the second capacitor, and the fourth resistor; the inverting input is connected to the reference voltage; and the output terminal (LIN input) is connected to the fourth resistor. The other end of the fourth resistor is connected to the power supply output terminal, the other end of the tenth resistor is connected to the LIN communication interface, and the other end of the eleventh resistor and the second capacitor is grounded.

[0032] Secondly, the present invention provides a communication device, including a housing, a circuit board, and the aforementioned vehicle-mounted LIN network transceiver circuit, wherein the circuit board is installed inside the housing, and the vehicle-mounted LIN network transceiver circuit is integrated into the circuit board.

[0033] Secondly, the present invention provides a vehicle infotainment system, including a microcontroller, a LIN transmission line, and the aforementioned communication device, wherein the microcontroller is connected to the LIN communication interface of the LIN transmission line via the communication device.

[0034] Compared with the prior art, the beneficial effects of the present invention are as follows: The vehicle-mounted LIN network transceiver circuit of the present invention, by setting an enable circuit, an output circuit, an input circuit, and a protection circuit, and connecting the enable circuit, output circuit, input circuit, and protection circuit between the microcontroller and the LIN communication interface, not only realizes the transmission and reception of LIN signals, but also provides overcurrent protection for the electrical signals transmitted from the LIN communication interface through the connection of the output circuit and the protection circuit with the LIN communication interface, so as to avoid device damage and failure to realize LIN communication; the enable circuit achieves low current consumption of the circuit, meeting the static current requirements in vehicle-mounted products.

[0035] This invention employs an analog circuit design, which can replace existing automotive-grade dedicated chips to realize the transmission and reception of LIN network signals and LIN network overcurrent protection, meeting the μA-level static current requirements of automotive products. The circuit is simple, the cost is low, and the circuit board utilization efficiency is higher, demonstrating high innovation and strong practicality.

[0036] The above description is merely an overview of the technical solutions of the embodiments of the present invention. In order to better understand the technical means of the embodiments of the present invention and to implement them in accordance with the contents of the specification, and to make the above and other objects, features and advantages of the embodiments of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0037] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0038] Figure 1 shows a schematic diagram of the structure of the vehicle-mounted LIN network transceiver circuit according to Embodiment 1 of the present invention;

[0039] Figure 2 shows the circuit schematic of the vehicle-mounted LIN network transceiver circuit according to Embodiment 2 of the present invention;

[0040] Figure 3 shows a schematic diagram of the vehicle infotainment system according to Embodiment 4 of the present invention.

[0041] in,

[0042] 110. Enable circuit; 120. Output circuit; 130. Input circuit; 140. Protection circuit; MCU (Microcontroller); LIN BUS (LIN communication interface);

[0043] Q1, first transistor; Q2, second transistor; Q3, third transistor; Q4, fourth transistor; Q5, fifth transistor;

[0044] C1, first capacitor; C2, second capacitor; D1, first diode; U1, voltage detector;

[0045] 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; R10, tenth resistor; R11, eleventh resistor;

[0046] 300. Vehicle infotainment system; 310. Communication device. Embodiments of the present invention

[0047] Exemplary embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein.

[0048] Example 1:

[0049] Figure 1 illustrates a first embodiment of an in-vehicle LIN network transceiver circuit according to the present invention, applied in a microcontroller (MCU) equipped with an enable signal terminal, a LIN output terminal, a LIN input terminal, and a power supply output terminal. This circuit includes an enable circuit 110, an output circuit 120, an input circuit 130, and a protection circuit 140.

[0050] Enable circuit 110 is connected to enable signal terminal, and enable circuit 110 is connected to LIN communication interface LIN BUS through protection circuit 140 to control the level signal of LIN communication interface LIN BUS; output circuit 120 is connected to LIN output terminal and LIN communication interface LIN BUS, and output circuit 120 is used to output the LIN signal of microcontroller MCU to LIN communication interface LIN BUS; input circuit 130 is connected to LIN input terminal and LIN communication interface LIN BUS, and input circuit 130 is used to output the LIN signal of LIN communication interface LIN BUS to microcontroller MCU.

[0051] The vehicle-mounted LIN network transceiver circuit of the present invention comprises an enable circuit 110, an output circuit 120, an input circuit 130, and a protection circuit 140. These circuits are connected between a microcontroller (MCU) and a LIN communication interface (LIN BUS). This not only enables the transmission and reception of LIN signals but also provides overcurrent protection for electrical signals transmitted from the LIN communication interface (LIN BUS) through the output circuit 120 and the protection circuit 140, preventing device damage and ensuring LIN communication. The enable circuit 110 also achieves low current consumption, meeting the static current requirements of vehicle-mounted products.

[0052] This invention employs an analog circuit design, which can replace existing automotive-grade dedicated chips to realize the transmission and reception of LIN network signals and LIN network overcurrent protection, meeting the μA-level static current requirements of automotive products. The circuit is simple, the cost is low, and the circuit board utilization efficiency is higher, demonstrating high innovation and strong practicality.

[0053] Example 2:

[0054] Figure 2-3 illustrates a first embodiment of an in-vehicle LIN network transceiver circuit according to the present invention. Based on embodiment 1, the circuit of the present invention includes an enable circuit 110, an output circuit 120, an input circuit 130, and a protection circuit 140. The enable circuit 110 is connected to an enable signal terminal and is connected to the LIN communication interface LIN BUS through the protection circuit 140 to control the level signal of the LIN communication interface LIN BUS. The output circuit 120 is connected to the LIN output terminal and the LIN communication interface LIN BUS, and is used to output the LIN signal of the microcontroller MCU to the LIN communication interface LIN BUS. The input circuit 130 is connected to the LIN input terminal and the LIN communication interface LIN BUS, and is used to output the LIN signal of the LIN communication interface LIN BUS to the microcontroller MCU.

[0055] In some optional implementations, the enable circuit 110 includes a second transistor Q2, a sixth resistor R6, an eighth resistor R8, and a fifth transistor Q5; the base of the second transistor Q2 is connected to the enable signal terminal, the collector is connected to the base of the fifth transistor Q5 through the sixth resistor R6, and the emitter is grounded; the emitter of the fifth transistor Q5 is connected to the power supply of the battery, and the collector is connected to the LIN communication interface LIN BUS through the protection circuit 140; one end of the eighth resistor R8 is connected to the base of the fifth transistor Q5, and the other end is connected to the emitter of the fifth transistor Q5.

[0056] In this embodiment, the emitter of the fifth transistor Q5 is connected to the battery power supply VBAT, and the collector is connected to the anode of the first diode D1 in the protection circuit; one end of the eighth resistor R8 is connected to the emitter of the fifth transistor Q5, and the other end is connected to the base of the fifth transistor Q5; one end of the sixth resistor R6 is connected to the emitter of the fifth transistor Q5, and the other end is connected to the collector of the second transistor Q2. The emitter of the second transistor Q2 is grounded, and its base is connected to the enable signal terminal LIN POWER EN.

[0057] The enabling circuit works as follows: When the system is powered on, if the microcontroller's (MCU) enable signal terminal LIN POWER EN outputs a high level, it transmits this high level to the base of the second transistor Q2, causing Q2 to saturate and conduct. At this time, the end of the sixth resistor R6 connected to the collector of the second transistor Q2 is essentially grounded. Simultaneously, the battery power supply VBAT, after being powered on, is transmitted to the base of the fifth transistor Q5 through the voltage divider of the eighth resistor R8 and the sixth resistor R6, causing Q5 to conduct. The battery power supply VBAT is then transmitted to the anode of the first diode D1 through the emitter of the fifth transistor Q5. If the MCU enable signal terminal LIN POWER EN outputs a low level, it transmits this low level to the base of the second transistor Q2, causing neither Q2 nor Q5 to conduct. The battery power supply VBAT cannot be transmitted to the anode of the first diode D1, thus preventing it from passing through the first diode D1 and the ninth resistor R9, tenth resistor R10, and eleventh resistor R11, reducing current consumption.

[0058] In some optional implementations, the protection circuit 140 includes a first diode D1, a ninth resistor R9, and a first capacitor C1; the cathode of the first diode D1 is connected to the collector of the fifth transistor Q5, and the anode of the first diode D1 is connected to the LIN communication interface LIN BUS through the ninth resistor R9; one end of the first capacitor C1 is connected to the LIN communication interface LIN BUS and the other end is grounded.

[0059] In this embodiment, the anode of the first diode D1 is connected to the collector of the fifth transistor Q5 in the enable circuit, and its cathode is connected to one end of the ninth resistor R9. The other end of the ninth resistor R9 is connected to the LIN communication interface LIN BUS. One end of the first capacitor C1 is connected to the LIN communication interface LIN BUS, and the other end is grounded.

[0060] The working principle of the protection circuit is as follows: The first diode D1 prevents the LIN communication interface LIN BUS current from flowing in reverse to the battery power supply VBAT, avoiding faults caused by reverse polarity; the ninth resistor R9 limits the current and prevents faults caused by the LIN BUS signal short-circuiting to ground; the first capacitor C1 acts as a filter and provides electrostatic protection to prevent faults caused by external signal interference.

[0061] In some alternative embodiments, a first possible implementation of the output circuit 120 is provided in this embodiment. The output circuit 120 includes a first resistor R1, a second resistor R2, a first transistor Q1, a third resistor R3, a fifth resistor R5, a third diode, a fourth diode, and a seventh resistor R7. One end of the first resistor R1 is connected to the LIN output terminal, and the other end is connected to the second resistor R2 and the base of the first transistor Q1. The collector of the first transistor Q1 is connected to the third resistor R3, the fifth resistor R5, the collector of the third transistor Q3, and the base of the fourth transistor Q4. The emitter of the fourth transistor Q4 is grounded. The collector of the fourth transistor Q4 is connected to the LIN communication terminal, and the emitter is connected to the base of the third transistor Q3 and the seventh resistor R7. The other end of the third resistor R3 is connected to the power supply output terminal, and the emitter of the third transistor Q3, the other end of the second resistor R2, the other end of the fifth resistor R5, and the other end of the seventh resistor R7 are grounded.

[0062] In this embodiment, one end of the first resistor R1 is connected to the signal LIN output terminal MCU TXD, and the other end is connected to the base of the first transistor Q1; one end of the second resistor R2 is connected to the base of the first transistor Q1, and the other end is connected to ground; one end of the third resistor R3 is connected to the power supply output terminal VCC, and the other end is connected to the collector of the first transistor Q1; one end of the fifth resistor R5 is connected to the collector of the first transistor Q1, and the other end is grounded; the collector of the transistor is connected to the collector of the first transistor Q1, the emitter is grounded, and the base is connected to the emitter of the fourth transistor Q4; the base of the fourth transistor Q4 is connected to the collector of the third transistor Q3, and the collector is connected to LIN BUS; the seventh resistor R7 is connected to the emitter of the fourth transistor Q4, and the other end is grounded.

[0063] The output circuit works as follows: When the system is powered on and the enable circuit is turned on, the battery power supply VBAT is transmitted to the signal LIN BUS through the first diode D1 and the ninth resistor R9. The LIN BUS voltage is close to the battery power supply VBAT voltage, i.e., LIN BUS is at a high level. If the MCU outputs a high level signal MCU TXD, this high level is transmitted to the base of the first transistor Q1 through the voltage divider of the first resistor R1 and the second resistor R2, causing the first transistor Q1 to saturate and conduct. At this time, the end of the third resistor R3, the fifth resistor R5, and the base of the fourth transistor Q4 connected to the collector of the first transistor Q1 is equivalent to grounding; the fourth transistor Q4 is not conducting. If the MCU's LIN output terminal MCU TXD outputs a low level, this low level is transmitted to the base of the first transistor Q1 through a voltage divider formed by resistors R1 and R2, causing Q1 to turn off. Meanwhile, the power supply VCC is transmitted to the base of the fourth transistor Q4 through a voltage divider formed by resistors R3 and R5, causing Q4 to turn on. LIN BUS is then grounded after passing through the collector of Q4 and resistor R7, resulting in a low level for LIN BUS. The third transistor Q3 and resistor R7 provide overcurrent protection. When the current flowing through R7 to LIN BUS is excessive, the VBE of the third transistor Q3 equals the voltage across resistor R7, reaching a threshold. Q3 then turns on, reducing the current flowing to the base of the fourth transistor Q4, and consequently reducing the on-state current of Q4, eventually achieving equilibrium and preventing Q4 from overcurrent breakdown.

[0064] In some alternative implementations, a second possible embodiment of the output circuit 120 is provided in this embodiment. The output circuit 120 includes a first resistor R1, a second resistor R2, a third diode, a fourth diode, and a seventh resistor R7. One end of the first resistor R1 is connected to the LIN output terminal, and the other end is connected to the second resistor R2, the collector of the third transistor Q3, the base of the fourth transistor Q4, and the power supply output terminal. The collector of the fourth transistor Q4 is connected to the LIN communication terminal, and its emitter is connected to the base of the third transistor Q3 and the seventh resistor R7. The emitter of the third transistor Q3, the other end of the second resistor R2, and the other end of the seventh resistor R7 are grounded. Compared to the first possible embodiment of the output circuit 120, the transistor Q1, resistors R3 and R5 in the output circuit can be omitted. The signal MCU TXD is connected to the base of the transistor Q4 after being divided by resistors R1 and R2. The inversion of the MCU TXD and LIN BUS signals can be processed at the MCU end, reducing some costs and the space occupied by the circuit board.

[0065] In some alternative implementations, the first transistor Q1, the second transistor Q2, the third transistor Q3, the fourth transistor Q4, and the fifth transistor Q5 are replaced with MOSFETs in the enable circuit and the output circuit. In this embodiment, considering the higher transmission rate of the LIN network, the NPN transistor can be replaced with an NMOS transistor, and the PNP transistor can be replaced with a PMOS transistor, with the voltage divider resistor values ​​adjusted accordingly to meet the requirements for transistor conduction.

[0066] In some optional embodiments, the input circuit 130 includes a voltage detector U1, a tenth resistor R10, an eleventh resistor R11, a second capacitor C2, and a fourth resistor R4. The voltage detector U1 is provided with a detection input terminal and a detection output terminal. The detection input terminal is connected to the tenth resistor R10, the eleventh resistor R11, and the second capacitor C2. The other end of the tenth resistor R10 is connected to the LIN communication interface LIN BUS, and the other ends of the eleventh resistor R11 and the second capacitor C2 are grounded. The detection output terminal is connected to the LIN input terminal and the fourth resistor R4. The other end of the fourth resistor R4 is connected to the power supply output terminal.

[0067] In this embodiment, one end of the tenth resistor R10 is connected to the LIN BUS, and the other end is connected to the input terminal of the voltage detector U1; one end of resistor R11 is grounded, and the other end is connected to the input terminal of the voltage detector U1; one end of capacitor C2 is grounded, and the other end is connected to the input terminal of the voltage detector U1; one end of the fourth resistor R4 is connected to the power supply output terminal VCC, and the other end is connected to the output terminal of the voltage detector U1; the LIN input terminal MCU RXD is connected to the output terminal of the voltage detector U1. The LIN input terminal MCU RXD in the input circuit can be split into two branches: one output to the MCU, and the other output to the device that needs to be woken up by the LIN network. When a change in the MCU RXD signal level is detected, the device can be woken up.

[0068] The input circuit works as follows: When the system is powered on and the enable circuit is turned on, the battery power supply VBAT is transmitted to the LIN communication interface LIN BUS through the first diode D1 and the ninth resistor R9. The LIN BUS voltage is close to the battery power supply VBAT voltage, i.e., LIN BUS is at a high level. When the voltage detector U1 detects that the input level is lower than the detection threshold, its output is low; when it detects that the input level is higher than the specified value, its output is high impedance. If LIN BUS is high, this high level is transmitted to the input of voltage detector U1 after being divided by the tenth resistor R10 and the eleventh resistor R11 and filtered by the second capacitor C2. When voltage detector U1 detects that the input level is higher than the detection threshold, its output is high impedance, and the power supply output VCC is transmitted to the LIN input MCU RXD through resistor R4. If the LIN BUS is low, the low level is transmitted to the input of the voltage detector U1 after being divided by the tenth resistor R10 and the eleventh resistor R11 and filtered by the second capacitor C2. The voltage detector U1 detects that the level at the input is lower than the detection threshold, and its output terminal outputs a low level, which is transmitted to the LIN input terminal MCU RXD.

[0069] In the above embodiment, the voltage detector can be replaced by a voltage comparator. Specifically, the input circuit 130 includes a voltage comparator, a tenth resistor R10, an eleventh resistor R11, a second capacitor C2, and a fourth resistor R4; the non-inverting input of the voltage comparator is connected to the tenth resistor R10, the eleventh resistor R11, the second capacitor C2, and the fourth resistor R4, the inverting input is connected to the reference voltage, and the output terminal (LIN input) is connected to the fourth resistor R4; the other end of the fourth resistor R4 is connected to the power supply output terminal, the other end of the tenth resistor R10 is connected to the LIN communication interface (LIN BUS), and the other end of the eleventh resistor R11 and the second capacitor C2 is grounded. In this embodiment, the voltage detector U1 in the input circuit can be replaced by a voltage comparator to compare the LIN BUS signal voltage and the reference voltage, thereby causing the MCU RXD signal level to follow the LIN BUS signal level. The reference voltage can be provided by the power supply output terminal or the power supply conversion of the battery.

[0070] Example 3:

[0071] Based on Embodiment 1 or Embodiment 2, the present invention provides a communication device, including a housing, a circuit board, and the aforementioned vehicle-mounted LIN network transceiver circuit. The circuit board is installed inside the housing, and the vehicle-mounted LIN network transceiver circuit is integrated within the circuit board. In this embodiment, the vehicle-mounted LIN network transceiver circuit can be integrated into the housing of the communication device, and the housing is provided with a first interface and a second interface. One end of the first interface is connected to the vehicle-mounted LIN network transceiver circuit, and the other end is connected to a microcontroller. One end of the second interface is connected to the vehicle-mounted LIN network transceiver circuit, and the other end is connected to a LIN communication interface.

[0072] This invention employs an analog circuit design, which can replace existing automotive-grade dedicated chips to realize the transmission and reception of LIN network signals and LIN network overcurrent protection, meeting the μA-level static current requirements of automotive products. The circuit is simple, the cost is low, and the circuit board utilization efficiency is higher, demonstrating high innovation and strong practicality.

[0073] Example 4:

[0074] Based on Embodiment 3, the present invention provides a vehicle infotainment system, including a microcontroller, a LIN transmission line, and the aforementioned communication device. The microcontroller is connected to the LIN communication interface of the LIN transmission line via the communication device.

[0075] In this embodiment, the microcontroller (MCU) is provided with an enable signal terminal, a LIN output terminal, a LIN input terminal, and a power output terminal. The circuit includes an enable circuit 110, an output circuit 120, an input circuit 130, and a protection circuit 140. The enable circuit 110 is connected to the enable signal terminal and is connected to the LIN communication interface (LIN BUS) through the protection circuit 140 to control the level signal of the LIN communication interface (LIN BUS). The output circuit 120 is connected to the LIN output terminal and the LIN communication interface (LIN BUS) and is used to output the LIN signal from the microcontroller (MCU) to the LIN communication interface (LIN BUS). The input circuit 130 is connected to the LIN input terminal and the LIN communication interface (LIN BUS) and is used to output the LIN signal from the LIN communication interface (LIN BUS) to the microcontroller (MCU).

[0076] The microcontroller may be a central processing unit (CPU), an application-specific integrated circuit (ASIC), or one or more integrated circuits configured to implement embodiments of the present invention. The one or more microcontrollers included in the vehicle infotainment system may be of the same type, such as one or more CPUs; or they may be of different types, such as one or more CPUs and one or more ASICs.

[0077] This invention employs an analog circuit design, which can replace existing automotive-grade dedicated chips to realize the transmission and reception of LIN network signals and LIN network overcurrent protection, meeting the μA-level static current requirements of automotive products. The circuit is simple, the cost is low, and the circuit board utilization efficiency is higher, demonstrating high innovation and strong practicality.

[0078] The algorithms or displays provided herein are not inherently related to any particular computer, virtual system, or other device. Furthermore, the embodiments of this invention are not directed to any particular programming language.

[0079] Numerous specific details are set forth in the specification provided herein. However, it will be understood that embodiments of the invention may be practiced without these specific details. Similarly, for the sake of brevity and to aid in understanding one or more aspects of the invention, in the description of exemplary embodiments of the invention above, various features of the embodiments are sometimes grouped together in a single embodiment, figure, or description thereof. The claims, which follow the detailed description, are hereby expressly incorporated into that detailed description, wherein each claim itself is a separate embodiment of the invention.

[0080] Those skilled in the art will understand that the modules in the device of the embodiment can be adaptively changed and placed in one or more devices different from that embodiment. Modules, units, or components in the embodiment can be combined into a single module, unit, or component, and further, they can be divided into multiple sub-modules, sub-units, or sub-components, except that at least some of such features and / or processes or units are mutually exclusive.

[0081] It should be noted that the above embodiments are illustrative of the invention and not restrictive, and that those skilled in the art can devise alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses should not be construed as limiting the claims. The word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The invention can be implemented by means of hardware comprising several different elements and by means of a suitably programmed computer. In the unit claims enumerating several means, several of these means may be embodied by the same item of hardware. The use of the words first, second, and third, etc., does not indicate any order. These words can be interpreted as names. The steps in the above embodiments, unless otherwise specified, should not be construed as limiting the order of execution.

Claims

1. A vehicle-mounted LIN network transceiver circuit, wherein, This circuit is applied in microcontrollers equipped with an enable signal terminal, a LIN output terminal, a LIN input terminal, and a power supply output terminal. It includes an enable circuit, an output circuit, an input circuit, and a protection circuit. The enabling circuit is connected to the enabling signal terminal, and the enabling circuit is connected to the LIN communication interface through the protection circuit to control the level signal of the LIN communication interface. The output circuit is connected to the LIN output terminal and the LIN communication interface. The output circuit is used to output the microcontroller's LIN to the LIN communication interface. The input circuit is connected to the LIN input terminal and the LIN communication interface, and the input circuit is used to output the LIN signal of the LIN communication interface to the microcontroller.

2. The vehicle-mounted LIN network transceiver circuit according to claim 1, wherein, The enabling circuit includes a second transistor, a sixth resistor, an eighth resistor, and a fifth transistor; The base of the second transistor is connected to the enable signal terminal, the collector is connected to the base of the fifth transistor through the sixth resistor, and the emitter is grounded; The emitter of the fifth transistor is connected to the power supply of the battery, and the collector is connected to the LIN communication interface through a protection circuit. One end of the eighth resistor is connected to the base of the fifth transistor, and the other end is connected to the emitter of the fifth transistor.

3. The vehicle-mounted LIN network transceiver circuit according to claim 2, wherein, The protection circuit includes a first diode, a ninth resistor, and a first capacitor; The cathode of the first diode is connected to the collector of the fifth transistor, and the anode of the first diode is connected to the LIN communication interface through the ninth resistor; one end of the first capacitor is connected to the LIN communication interface and the other end is grounded.

4. The vehicle-mounted LIN network transceiver circuit according to claim 3, wherein, The output circuit includes a first resistor, a second resistor, a third diode, a fourth diode, and a seventh resistor; One end of the first resistor is connected to the output terminal of the LIN transistor, and the other end is connected to the second resistor, the collector of the third transistor, the base of the fourth transistor, and the power supply output terminal. The collector of the fourth transistor is connected to the LIN communication, and the emitter is connected to the base of the third transistor and the seventh resistor. The emitter of the third transistor, the other end of the second resistor, and the other end of the seventh resistor are grounded.

5. A vehicle-mounted LIN network transceiver circuit according to claim 3, wherein, The output circuit includes a first resistor, a second resistor, a first transistor, a third resistor, a fifth resistor, a third diode, a fourth diode, and a seventh resistor; One end of the first resistor is connected to the LIN output terminal, and the other end is connected to the second resistor and the base of the first transistor. The collector of the first transistor is connected to the third resistor, the fifth resistor, the collector of the third transistor, and the base of the fourth transistor, while the emitter is grounded. The collector of the fourth transistor is connected to the LIN communication, and the emitter is connected to the base of the third transistor and the seventh resistor. The other end of the third resistor is connected to the power supply output terminal, and the emitter of the third transistor, the other end of the second resistor, the other end of the fifth resistor, and the other end of the seventh resistor are grounded.

6. A vehicle-mounted LIN network transceiver circuit according to claim 4 or 5, wherein, Replace the first, second, third, fourth, and fifth transistors with MOSFETs.

7. A vehicle-mounted LIN network transceiver circuit according to claim 6, wherein, The input circuit includes a voltage detector, a tenth resistor, an eleventh resistor, a second capacitor, and a fourth resistor; The voltage detector is provided with a detection input terminal and a detection output terminal. The detection input terminal is connected to the tenth resistor, the eleventh resistor, and the second capacitor. The other end of the tenth resistor is connected to the LIN communication interface, and the other ends of the eleventh resistor and the second capacitor are grounded. The detection output terminal is connected to the LIN input terminal and the fourth resistor, and the other end of the fourth resistor is connected to the power supply output terminal.

8. The vehicle-mounted LIN network transceiver circuit according to claim 6, wherein, The input circuit includes a voltage comparator, a tenth resistor, an eleventh resistor, a second capacitor, and a fourth resistor; The non-inverting input of the voltage comparator is connected to the tenth resistor, the eleventh resistor, the second capacitor, and the fourth resistor; the inverting input is connected to the reference voltage; and the output terminal (LIN input) is connected to the fourth resistor. The other end of the fourth resistor is connected to the power supply output terminal, the other end of the tenth resistor is connected to the LIN communication interface, and the other end of the eleventh resistor and the second capacitor is grounded.

9. A communication device, wherein, The device includes a housing, a circuit board, and the vehicle-mounted LIN network transceiver circuit according to any one of claims 1-8, wherein the circuit board is installed inside the housing and the vehicle-mounted LIN network transceiver circuit is integrated into the circuit board.

10. A vehicle infotainment system, wherein, It includes a microcontroller, a LIN transmission line, and the communication device as described in claim 9, wherein the microcontroller is connected to the LIN communication interface of the LIN transmission line through the communication device.

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