Infineon TLE7250VSJ LIN Bus Transceiver: Key Features and Application Design Guide

The Infineon TLE7250VSJ is a highly integrated, monolithic LIN (Local Interconnect Network) transceiver designed to interface between a LIN protocol controller and the physical bus in automotive networks. As a key enabler for sensor and actuator communication in body electronics, this device stands out for its robustness, low power consumption, and compliance with the latest automotive standards.

Key Features

Compliance with Latest Standards: The TLE7250VSJ is fully compliant with the LIN 2.2/2.2A, SAE J2602-2, and ISO 17987-4 specifications, ensuring interoperability within modern automotive architectures.

Exceptional ESD Robustness: It offers superior system-level electrostatic discharge (ESD) protection, rated up to ±8 kV according to IEC 61000-4-2 on the LIN bus pin. This significantly enhances the reliability and durability of the network in harsh electrical environments.

Very Low Standby Current: A critical feature for automotive applications is power management. The transceiver boasts an ultra-low current consumption in low-power standby mode (typ. 7 µA), which is essential for meeting the strict quiescent current requirements of modern vehicles to prevent battery drain.

Integrated Wake-Up Features: The device supports wake-up through both local and remote wake-up requests via the LIN bus. This allows the system to remain in a low-power state until communication is required, improving overall energy efficiency.

High Immunity to EMI: The TLE7250VSJ is designed to operate reliably in the electrically noisy environment of an automobile, demonstrating high electromagnetic immunity (EMI) to disturbances.

Thermal Protection and Fail-Safe Operation: Built-in protection mechanisms include thermal shutdown and protection against short circuits to battery voltage and ground, safeguarding the device and the microcontroller from potential damage.

Application Design Guide

Designing with the TLE7250VSJ requires attention to several key areas to ensure optimal performance:

1. Power Supply (VSUP): A stable power supply is crucial. It is recommended to use a decoupling capacitor (e.g., 100 nF) placed as close as possible to the VSUP pin and the ground terminal to suppress high-frequency noise.

2. LIN Bus Interface: The LIN bus line is a single-wire connection susceptible to external disturbances. To ensure signal integrity and minimize EMI:

Use a series resistor (Rs) of 1 kΩ between the TXD input and the microcontroller to limit current injection.

Implement a RC filter (e.g., 470 Ω + 4.7 nF) on the RXD output to the microcontroller to smooth the signal.

The bus output is current-limited, making an external series resistor between the LIN pin and the bus line typically unnecessary.

3. Slope Control: The TLE7250VSJ features controlled slew rates on the LIN bus output, which helps to reduce electromagnetic emissions (EME). This is automatically managed by the internal circuitry, simplifying design.

4. Wake-Up and Sleep Management: To utilize the low-power features effectively, the host microcontroller must be able to manage the transceiver's modes (Normal, Sleep, Standby) via the EN (Enable) pin. Proper handling of local and remote wake-up events is key to designing energy-efficient control nodes.

5. PCB Layout: For optimal EMC performance, keep the traces between the transceiver and the microcontroller short. The ground pin should be connected to the PCB's ground plane with a low-inductance path. The LIN bus connection should be properly shielded if necessary.

Typical Applications

The TLE7250VSJ is ideal for a wide range of automotive sub-nodes, including:

Door control modules (window lifters, mirror adjustment)

Seat control units (motors, sensors)

Steering wheel controls

Smart sensors (rain/light, position sensors)

Roof and climate control modules

ICGOODFIND: The Infineon TLE7250VSJ is a robust and reliable solution for LIN network design, offering a perfect blend of low power consumption, high ESD protection, and full standard compliance. Its integrated features simplify design while ensuring performance in the demanding automotive environment, making it an excellent choice for a vast array of body electronics applications.

Keywords: LIN Transceiver, Automotive Networking, Low Power Consumption, ESD Protection, ISO 17987-4