An isolated lin bus communication wake-up circuit and battery management system

Abstract

This invention relates to the technical fields of battery management systems, and provides an isolated LIN bus communication wake-up circuit and a battery management system. The circuit includes: a power data isolation module connected to an MCU and a LIN level conversion chip; and an isolated wake-up circuit connected to the LIN bus and the MCU. When the BMS goes into sleep mode and the power data isolation module is turned off, the wake-up level change signal sent by an external device is processed by the isolated wake-up circuit to form an MCU wake-up signal, waking up the MCU. After the MCU is woken up, the power data isolation module is restarted to establish a communication link. The isolated wake-up circuit includes a passive capacitive coupling unit, a drive level generation unit, and a noise filtering unit. Under the condition of complete power-off isolation, a novel architecture combining pure passive capacitive coupling and multi-stage transistor amplification is used to achieve remote wake-up of the LIN bus. The entire system's sleep current is only 30μA, balancing extremely low power consumption and remote wake-up capability. The circuit structure is simple, low-cost, and highly reliable.

Description

Technical Field

[0001] This invention relates to the field of communication circuit technology for battery management systems, and more particularly to an isolated LIN bus communication wake-up circuit and battery management system applied to a BMS. Background Technology

[0002] See Figure 2 In existing BMS systems, to reduce power consumption, the MCU actively isolates communication in sleep mode. However, this prevents external devices from waking the BMS for communication. When the battery status needs to be checked, the external device cannot obtain the data. Specifically, the MCU connects to the UART-LIN conversion chip via a power-data isolation module (isolation power supply + digital isolator) to achieve LIN bus communication with external devices. When the BMS enters sleep mode, the MCU shuts off the isolation power supply via the power control pin PWR1_EN, stopping power supply to the UART-LIN level conversion chip and the digital isolator. Because the digital isolator is de-energized and the isolation link is completely interrupted, any level changes on the LIN bus cannot be transmitted to the MCU, thus preventing external devices from sending a remote wake-up signal via the LIN bus to wake the MCU when the BMS is in sleep mode.

[0003] As can be seen, in existing technologies, the wake-up path is completely interrupted after the isolated power supply is turned off. External devices cannot actively obtain battery status data from the BMS and can only establish communication by actively waking up the BMS itself, resulting in extremely poor interaction flexibility. Moreover, existing technologies cannot support LIN bus remote wake-up and remote diagnostic functions, limiting the functional completeness of BMS products. Users need to manually trigger BMS wake-up through methods such as plugging in a charger, leading to a poor user experience. Summary of the Invention

[0004] This invention provides an isolated LIN bus communication wake-up circuit, which aims to solve the technical problem in the prior art that the wake-up path is completely interrupted after the isolated power is turned off, and it is impossible to achieve both low power consumption and remote wake-up.

[0005] In a first aspect, the present invention provides an isolated LIN bus communication wake-up circuit applied to a BMS, comprising: a power data isolation module electrically connected to an MCU and a LIN level conversion chip on the BMS, wherein the LIN level conversion chip is used to electrically connect to the LIN bus of an external communication device; and an isolated wake-up circuit electrically connected to the LIN bus of the LIN level conversion chip and the MCU; when the BMS enters sleep mode, the MCU controls the power data isolation module to shut down, thereby de-energizing the LIN level conversion chip; when the external communication device sends a wake-up level change signal via the LIN bus, the wake-up level change signal is processed by the isolated wake-up circuit to form an MCU wake-up signal, the MCU wake-up signal is transmitted to the MCU to wake up the MCU, and after the MCU is woken up, the power data isolation module is restarted to establish a LIN bus communication link between the MCU and the external communication device.

[0006] Furthermore, the isolated wake-up circuit includes: a passive capacitive coupling unit electrically connected to the LIN bus between the LIN level conversion chip and the external communication device, used to passively couple the wake-up level change signal on the LIN bus after the power data isolation module is turned off; and a drive level generation unit electrically connected to the passive capacitive coupling unit and the MCU, used to receive the wake-up level change signal, perform level conversion and amplification on the wake-up level change signal, and generate an MCU wake-up signal in the form of a drive level for input to the MCU. The isolated wake-up circuit includes a passive capacitive coupling unit and a drive level generation unit, which passively couple the wake-up signal and then generate a drive level through level conversion and amplification, so that signal transmission does not rely on an isolated power supply, achieving efficient coordination between pure passive coupling and active processing.

[0007] Furthermore, the isolated wake-up circuit also includes a noise filtering unit, electrically connected to the drive level generation unit, used to filter out bus noise interference carried in the MCU wake-up signal before the MCU wake-up signal is input to the MCU. The noise filtering unit filters out bus noise interference before the MCU wake-up signal is input to the MCU, preventing false wake-ups and improving wake-up reliability.

[0008] Furthermore, the passive capacitive coupling unit includes a first isolation capacitor C1, a first resistor R1, a second resistor R2, and a second isolation capacitor C2 connected in series. The first isolation capacitor C1 is connected to the LIN bus, the second isolation capacitor C2 is grounded, and the first resistor R1 and the second resistor R2 are connected to the input terminal of the drive level generation unit. The output terminal of the drive level generation unit is connected to the MCU. The passive capacitive coupling unit adopts a specific architecture of C1, R1, R2, and C2 connected in series, with C1 connected to the LIN bus and C2 grounded. It uses a simple voltage divider network to complete the signal isolation coupling and voltage divider output, resulting in a simple and reliable structure.

[0009] Further, the drive level generation unit includes a first transistor Q1, a second transistor Q2, a third transistor Q3, a fourth transistor Q4, a third resistor R3, a fourth resistor R4, a fifth resistor R5, and a seventh resistor R7; the base of the first transistor Q1 is the input terminal of the drive level generation unit, connected to the common node of the first resistor R1 and the second resistor R2, for receiving the wake-up level change signal; the collector of the first transistor Q1 is connected to the emitter of the third transistor Q3, the seventh resistor R7, and the VD of the MCU through the fourth transistor Q4 and the third resistor R3 connected in series. Pin D; the base of the second transistor Q2 is connected to the common node of the first resistor R3 and the fourth resistor R4. The emitter of the second transistor Q2 is connected to the base of the third transistor Q3. The collectors of the second transistor Q2 and the third transistor Q3 are connected to the base of the fourth transistor Q4 through the fifth resistor R5. The common node of the collector of the fourth transistor Q4 and the seventh resistor R7 serves as the output terminal of the drive level generation unit and is connected to the WAKUP_INT pin of the MCU to receive the MCU wake-up signal. The emitters of the fourth transistor Q4 and the first transistor Q1 are both grounded. The drive level generation unit adopts a four-stage transistor architecture. Q1 performs level conversion, Q2 and Q3 form a Darlington structure to amplify current, and Q4 outputs the drive level. It can amplify weak coupled signals to a drive level that can trigger an MCU interrupt, with a fast response speed.

[0010] Furthermore, the isolated wake-up circuit also includes a noise filtering unit. The noise filtering unit is electrically connected to the drive level generation unit and is used to filter out bus noise interference carried in the MCU wake-up signal before the MCU wake-up signal is input to the MCU. The noise filtering unit includes a third capacitor C3 and a sixth resistor R6 connected together to the base of the fourth transistor Q4; the other ends of the third capacitor C3 and the sixth resistor R6 are grounded together. The noise filtering unit, composed of C3 and R6 connected to the base of Q4, has a simple structure and effectively filters out bus noise interference.

[0011] Furthermore, the LIN bus has a communication rate of 9600bps. The capacitance of the first isolation capacitor C1 and the second isolation capacitor C2 is 1μF. The resistance of the first resistor R1 is 100KΩ, and the resistance of the second resistor R2 is 10KΩ. Based on the capacitive reactance formula XC=1 / (2πfC), the total capacitive reactance of C1 and C2 is approximately 8.29Ω. When the LIN bus voltage is 12V, the voltage drop across the second resistor R2 is approximately 1V, and the passive capacitor coupling unit consumes approximately 109μA of current. For the 9600bps LIN bus communication rate, the parameters of C1, C2, R1, and R2 are optimized to ensure that the voltage drop across R2 is greater than the Q1 conduction threshold, guaranteeing reliable triggering. Simultaneously, the passive capacitor coupling unit consumes only approximately 109μA of current, far less than traditional optocoupler solutions, achieving extremely low wake-up power consumption.

[0012] Furthermore, the isolated LIN bus communication wake-up circuit is configured to include: Step S1: The BMS enters sleep mode, the MCU controls the power data isolation module to shut down, the LIN level conversion chip loses power, and the MCU enters low power mode. Step S2: The external communication device sends a wake-up level change signal through the LIN bus, and the passive capacitive coupling unit couples the wake-up level change signal in a passive manner. Step S3: The wake-up level change signal is amplified and level converted by the drive level generation unit to form an MCU wake-up signal in the form of a drive level. The noise filtering unit filters out the bus noise interference in the MCU wake-up signal to obtain the MCU wake-up signal after filtering out the bus noise interference. Step S4: The MCU wake-up signal after filtering out bus noise interference is input to the MCU's WAKUP_INT pin, which receives the MCU wake-up signal, through the drive level generation unit, and the MCU is woken up; Step S5: After the MCU is woken up, the power data isolation module is restarted to establish a LIN bus communication link between the MCU and the external communication device.

[0013] In this solution, the circuit works in concert with complete functions of sleep, coupling, amplification and filtering, wake-up and communication recovery. After the BMS goes into sleep mode and the power and data isolation module is turned off, the isolated wake-up circuit independently processes the wake-up level change signal on the LIN bus to form the MCU wake-up signal. After the MCU is woken up, the power and data isolation module is turned on again to establish a communication link. This achieves the beneficial effect that the BMS can still be remotely woken up by external devices in the low-power sleep mode when the isolated power is turned off.

[0014] Furthermore, the power data isolation module includes an isolation power supply and a digital isolator. In step S1, after the power data isolation module is turned off, the power consumption of the isolation power supply, digital isolator, and LIN level conversion chip is zero. The capacitor circuit in the passive capacitor coupling unit is in a DC steady state and does not consume power. The MCU is in a 30μA low-power mode, and the total sleep current of the entire BMS system is 30μA. After the power data isolation module is turned off, the power consumption on the isolation side is zero, the capacitor circuit has no DC power consumption, the MCU is in a 30μA low-power mode, and the total sleep current of the entire system is only 30μA, which significantly reduces power consumption compared to the continuous power supply solution.

[0015] Secondly, the present invention provides a battery management system that integrates the isolated LIN bus communication wake-up circuit described in any of the above claims.

[0016] The battery management system of the present invention integrates the isolated LIN bus communication wake-up circuit described in any of the above claims. By using the isolated wake-up circuit to independently process the wake-up level change signal on the LIN bus to form an MCU wake-up signal after the BMS goes into sleep mode and the power data isolation module is turned off, the MCU is woken up and then the power data isolation module is turned on again to establish a communication link. This achieves the beneficial effect of being able to be remotely woken up by external devices even in the extremely low power sleep state when the isolated power is turned off.

[0017] Compared with the prior art, the beneficial effects of this invention are as follows: This invention provides an isolated LIN bus communication wake-up circuit and a battery management system. The isolated LIN bus communication wake-up circuit is applied to a battery management system. The circuit includes: a power data isolation module electrically connected to the MCU and LIN level conversion chip on the BMS, wherein the LIN level conversion chip is used to electrically connect to the LIN bus of an external communication device; and an isolated wake-up circuit electrically connected to the LIN bus of the LIN level conversion chip and the MCU. When the BMS enters sleep mode, the MCU controls the power data isolation module to shut down, thereby de-energizing the LIN level conversion chip. When the external communication device sends a wake-up level change signal via the LIN bus, the wake-up level change signal is processed by the isolated wake-up circuit to form an MCU wake-up signal. The MCU wake-up signal is transmitted to the MCU to wake it up. After the MCU is woken up, the power data isolation module is restarted to establish a LIN bus communication link between the MCU and the external communication device. The isolated LIN bus communication wake-up circuit provided by this invention breaks through the conventional thinking that the wake-up detection circuit must be located on the powered side or require its own power supply. Even with the power data isolation module turned off, the MCU can still be remotely woken up via the LIN bus, achieving both extremely low sleep power consumption and remote wake-up and remote diagnostic capabilities for external devices. Attached Figure Description

[0018] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. Some specific embodiments of the invention will be described in detail below with reference to the accompanying drawings in an exemplary and non-limiting manner. The same reference numerals in the drawings designate the same or similar parts or components. It should be understood by those skilled in the art that these drawings are not necessarily drawn to scale. In the drawings: Figure 1 This is a system architecture diagram of the isolated LIN bus communication wake-up circuit according to an embodiment of this application; Figure 2 This is the architecture diagram of the LIN communication circuit in a traditional BMS; Figure 3 This is a schematic diagram of the isolated LIN bus communication wake-up circuit according to an embodiment of this application. Detailed Implementation

[0019] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0020] Example 1 Reference Figure 1 This application provides an isolated LIN bus communication wake-up circuit, which is applied to a BMS, i.e., a battery management system.

[0021] Figure 1 The architecture of the isolated LIN bus communication wake-up circuit is illustrated. The MCU on the BMS is connected to the LIN level conversion chip via a power-data isolation module (containing an isolated power supply and a digital isolator). The LIN level conversion chip is used to connect to the LIN bus of external communication devices. The isolated wake-up circuit is independent of the power-data isolation module; one end is connected to the LIN bus, and the other end is connected to the MCU's WAKUP_INT pin, which receives the MCU wake-up signal. The MCU controls the power-data isolation module to turn on and off via the power control pin PWR1_EN.

[0022] Example 2 Reference Figure 3 This application provides an isolated LIN bus communication wake-up circuit. Figure 3The principle of an isolated LIN bus communication wake-up circuit is illustrated, including its specific structure. In this embodiment, the isolated wake-up circuit includes a passive capacitive coupling unit and a drive level generation unit.

[0023] The passive capacitive coupling unit includes a first isolation capacitor C1, a first resistor R1, a second resistor R2, and a second isolation capacitor C2 connected in series. One end of the first isolation capacitor C1 is connected to the LIN bus between the LIN level conversion chip and the external communication device, and one end of the second isolation capacitor C2 is grounded (MCU-side isolation ground). The first resistor R1 and the second resistor R2 are connected in series, and their common node serves as the output terminal of the passive capacitive coupling unit, connected to the input terminal of the drive level generation unit. The wake-up level change signal is coupled and transmitted through an AC loop formed by the LIN bus, C1, R1, R2, C2, and ground, generating a voltage divider signal across the second resistor R2.

[0024] The drive level generation unit includes a first transistor Q1, a second transistor Q2, a third transistor Q3, a fourth transistor Q4, a third resistor R3, a fourth resistor R4, a fifth resistor R5, and a seventh resistor R7. The base of the first transistor Q1 serves as the input terminal of the drive level generation unit and is connected to the common node of the first resistor R1 and the second resistor R2. The collector of the first transistor Q1 is connected to the emitter of the third transistor Q3, the seventh resistor R7, and the VDD pin of the MCU via the fourth resistor R4 and the third resistor R3 connected in series. The base of the second transistor Q2 is connected to the common node of the third resistor R3 and the fourth resistor R4. The emitter of the second transistor Q2 is connected to the base of the third transistor Q3. The collectors of the second transistor Q2 and the third transistor Q3 are connected to the base of the fourth transistor Q4 via the fifth resistor R5. The common node between the collector of the fourth transistor Q4 and the seventh resistor R7 serves as the output of the drive level generation unit, connected to the WAKUP_INT pin of the MCU to receive the MCU wake-up signal. The emitters of both the fourth transistor Q4 and the first transistor Q1 are grounded.

[0025] Taking a LIN bus communication rate of 9600bps as an example, the capacitance values ​​of the first isolation capacitor C1 and the second isolation capacitor C2 are both selected as 1μF, the resistance value of the first resistor R1 is 100KΩ, and the resistance value of the second resistor R2 is 10KΩ. Based on the capacitive reactance formula XC=1 / (2πfC), the total capacitive reactance of C1 and C2 is approximately 8.29Ω. When the LIN bus voltage is 12V, the voltage drop across the second resistor R2 is approximately 1V, which is greater than the base-emitter turn-on threshold voltage of the first transistor Q1 (approximately 0.6V), ensuring reliable conduction of the first transistor Q1. The passive capacitive coupling unit consumes approximately 109μA of current when transmitting the wake-up signal, which is far less than the milliampere-level drive current of traditional optocoupler solutions.

[0026] Furthermore, the isolation wake-up circuit also includes a noise filtering unit. The noise filtering unit is electrically connected to the drive level generation unit and is used to filter out bus noise interference carried in the MCU wake-up signal before the MCU wake-up signal is input to the MCU. The noise filtering unit includes a third capacitor C3 and a sixth resistor R6, both connected to the base of the fourth transistor Q4, and the other ends of the third capacitor C3 and the sixth resistor R6 are grounded.

[0027] Example 3 Combination Figure 1 and Figure 3 This application provides an embodiment of the operation process of an isolated LIN bus communication wake-up circuit, the operation process including: Step S1: The BMS enters sleep mode. The MCU controls the power data isolation module to shut down via the power control pin PWR1_EN. The isolation power supply stops supplying power to the digital isolator and the LIN level conversion chip, and the LIN level conversion chip is de-energized. The MCU enters low-power Stop mode.

[0028] Step S2: The external communication device sends a wake-up level change signal via the LIN bus. Since the isolation wake-up circuit is independent of the power and data isolation module, the first isolation capacitor C1 and the second isolation capacitor C2 in the passive capacitor coupling unit passively couple the wake-up level change signal, generating a voltage-divided wake-up level change signal across the second resistor R2.

[0029] Step S3: The wake-up level change signal, obtained by voltage division across the second resistor R2, is input to the base of the first transistor Q1. When the voltage division exceeds the conduction threshold voltage of Q1, the first transistor Q1 conducts, achieving level conversion. The conduction current of Q1 is amplified by the Darlington structure formed by the second transistor Q2 and the third transistor Q3, driving the fourth transistor Q4 to conduct. Simultaneously, the third capacitor C3 and the sixth resistor R6 in the noise filtering unit filter out bus noise interference.

[0030] Step S4: After the fourth transistor Q4 is turned on, it pulls down the WAKUP_INT pin level connected to the seventh resistor R7, generating a falling edge interrupt as the MCU wake-up signal. After detecting this falling edge interrupt, the MCU exits the Stop low-power mode, completing the wake-up process.

[0031] Step S5: After the MCU is woken up, the power data isolation module is restarted through the power control pin PWR1_EN. The isolation power supply resumes to power the digital isolator and LIN level conversion chip, and the LIN bus communication link between the MCU and the external communication device is restored. The external device can then obtain the battery status data of the BMS.

[0032] Regarding sleep power consumption, after the power data isolation module is turned off, the power consumption of the isolation power supply, digital isolation chip, and LIN level conversion chip is zero. Capacitors C1 and C2 and resistors R1 and R2 in the passive capacitive coupling unit do not consume power under DC steady-state conditions without communication. The MCU is in Stop low-power mode, with a sleep current of only 30μA. Therefore, the total sleep current of the entire BMS system is 30μA, which is hundreds of times lower than the traditional continuous power supply scheme (the combined power consumption of the isolation power supply, digital isolation chip, and LIN level conversion chip is approximately 10mA).

[0033] The isolation wake-up circuit in this embodiment is built entirely with discrete resistors, capacitors, and transistors, and does not include optocouplers, digital isolators, or circuit structures that rely on the built-in INH wake-up pin of a dedicated LIN transceiver. With the power and data isolation modules completely shut down, it can independently achieve remote wake-up via the LIN bus, is compatible with various brands and models of LIN level conversion chips, and features a simple structure, low cost, and high reliability.

[0034] Based on the same inventive concept, this application also provides a battery management system that integrates an isolated LIN bus communication wake-up circuit as described in any of the previous embodiments.

[0035] It should be noted that the above embodiments are merely preferred embodiments of the present invention, and the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention, and the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. An isolated LIN bus communication wake-up circuit, applied in BMS, characterized in that, include: The power data isolation module is electrically connected to the MCU and LIN level conversion chip on the BMS, respectively. The LIN level conversion chip is used to electrically connect to the LIN bus of external communication devices. An isolated wake-up circuit is electrically connected to the LIN bus of the LIN level conversion chip and the MCU, respectively. When the BMS enters sleep mode, the MCU controls the power data isolation module to shut down, thereby de-energizing the LIN level conversion chip. When the external communication device sends a wake-up level change signal via the LIN bus, the wake-up level change signal is processed by the isolation wake-up circuit to form an MCU wake-up signal. The MCU wake-up signal is transmitted to the MCU to wake it up. After the MCU is woken up, the power data isolation module is restarted to establish a LIN bus communication link between the MCU and the external communication device.

2. The isolated LIN bus communication wake-up circuit according to claim 1, characterized in that, The isolated wake-up circuit includes: A passive capacitive coupling unit is electrically connected to the LIN bus between the LIN level conversion chip and the external communication device. It is used to passively couple the wake-up level change signal on the LIN bus after the power data isolation module is turned off. The drive level generation unit is electrically connected to the passive capacitive coupling unit and the MCU respectively. It is used to receive the wake-up level change signal, perform level conversion and amplification on the wake-up level change signal, and generate an MCU wake-up signal in the form of a drive level for input to the MCU.

3. The isolated LIN bus communication wake-up circuit according to claim 2, characterized in that, The isolation wake-up circuit further includes a noise filtering unit, which is electrically connected to the drive level generation unit, and is used to filter out bus noise interference carried in the MCU wake-up signal before the MCU wake-up signal is input to the MCU.

4. The isolated LIN bus communication wake-up circuit according to claim 2, characterized in that, The passive capacitive coupling unit includes a first isolation capacitor C1, a first resistor R1, a second resistor R2, and a second isolation capacitor C2 connected in series. The first isolation capacitor C1 is connected to the LIN bus, the second isolation capacitor C2 is grounded, the first resistor R1 and the second resistor R2 are connected to the input terminal of the drive level generation unit, and the output terminal of the drive level generation unit is connected to the MCU.

5. The isolated LIN bus communication wake-up circuit according to claim 3, characterized in that, The drive level generation unit includes a first transistor Q1, a second transistor Q2, a third transistor Q3, a fourth transistor Q4, a third resistor R3, a fourth resistor R4, a fifth resistor R5, and a seventh resistor R7. The base of the first transistor Q1 is the input terminal of the drive level generation unit and is connected to the common node of the first resistor R1 and the second resistor R2 to receive the wake-up level change signal. The collector of the first transistor Q1 is connected to the emitter of the third transistor Q3, the seventh resistor R7, and the VDD pin of the MCU through the fourth transistor Q4 and the third resistor R3 connected in series. The base of the second transistor Q2 is connected to the common node of the first resistor R3 and the fourth resistor R4. The emitter of the second transistor Q2 is connected to the base of the third transistor Q3. The collectors of the second transistor Q2 and the third transistor Q3 are connected to the base of the fourth transistor Q4 through the fifth resistor R5. The common node of the collector of the fourth transistor Q4 and the seventh resistor R7 serves as the output terminal of the drive level generation unit and is connected to the WAKUP_INT pin of the MCU that receives the MCU wake-up signal. The emitters of the fourth transistor Q4 and the first transistor Q1 are both grounded.

6. The isolated LIN bus communication wake-up circuit according to claim 5, characterized in that, The noise filtering unit includes a third capacitor C3 and a sixth resistor R6 that are connected together to the base of the fourth transistor Q4; the other ends of the third capacitor C3 and the sixth resistor R6 are grounded together.

7. The isolated LIN bus communication wake-up circuit according to claim 4, characterized in that, The LIN bus has a communication rate of 9600bps. The capacitance of the first isolation capacitor C1 and the second isolation capacitor C2 is 1μF. The resistance of the first resistor R1 is 100KΩ and the resistance of the second resistor R2 is 10KΩ. Based on the capacitive reactance formula XC=1 / (2πfC), the total capacitive reactance of C1 and C2 is approximately 8.29Ω. When the LIN bus voltage is 12V, the voltage drop obtained by the second resistor R2 is approximately 1V, and the passive capacitive coupling unit consumes approximately 109μA of current.

8. An isolated LIN bus communication wake-up circuit, characterized in that, The isolated LIN bus communication wake-up circuit is configured to include: Step S1: The BMS enters sleep mode, the MCU controls the power data isolation module to shut down, the LIN level conversion chip loses power, and the MCU enters low power mode. Step S2: The external communication device sends a wake-up level change signal through the LIN bus, and the passive capacitive coupling unit couples the wake-up level change signal in a passive manner. Step S3: The wake-up level change signal is amplified and level converted by the drive level generation unit to form an MCU wake-up signal in the form of a drive level. The noise filtering unit filters out the bus noise interference in the MCU wake-up signal to obtain the MCU wake-up signal after filtering out the bus noise interference. Step S4: The MCU wake-up signal after filtering out bus noise interference is input to the MCU's WAKUP_INT pin, which receives the MCU wake-up signal, through the drive level generation unit, and the MCU is woken up; Step S5: After the MCU is woken up, the power data isolation module is restarted to establish a LIN bus communication link between the MCU and the external communication device.

9. The isolated LIN bus communication wake-up circuit according to claim 8, characterized in that, The power data isolation module includes an isolation power supply and a digital isolator; in step S1, after the power data isolation module is turned off, the power consumption of the isolation power supply, digital isolator and LIN level conversion chip is zero; the capacitor circuit in the passive capacitor coupling unit is in DC steady state and does not consume power; the MCU is in a low-power mode of 30μA, and the total sleep current of the entire BMS system is 30μA.

10. A battery management system, characterized in that, The battery management system integrates the isolated LIN bus communication wake-up circuit as described in any one of claims 1-9.

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