Infineon TLE7250LEXUMA1 LIN Transceiver: Features, Applications, and Design Considerations

The Infineon TLE7250LEXUMA1 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 of robust and cost-effective communication in body electronics and other in-vehicle subsystems, this device stands out for its reliability and advanced feature set.

Key Features

The TLE7250LEXUMA1 is packed with features that make it a premier choice for automotive designers. Its core functionality is to convert logic-level signals from a microcontroller (MCU) into a bus signal and vice versa, complying with the LIN 2.x, SAE J2602, and ISO 17987-4 standards.

A primary highlight is its extremely low quiescent current in sleep mode, typically just 6 µA. This is critical for modern vehicles, where minimizing battery drain when the ignition is off is paramount. The device supports multiple wake-up sources, including both local and remote wake-up via the LIN bus, ensuring the network can be reactivated when needed.

Robustness is engineered into its core. It features high immunity to Electrostatic Discharge (ESD), exceeding 8 kV according to the Human Body Model (HBM), and offers excellent EMC performance. Built-in protection mechanisms include protection against loss of battery and ground, over-temperature shutdown, and transmit data (TXD) dominant timeout to prevent bus blockades.

Primary Applications

The TLE7250LEXUMA1 finds its home in a wide array of automotive applications where a simple, low-cost, single-wire network is sufficient. Its most common uses include:

Body Control Modules (BCM): Acting as a central hub for convenience features.

Sensor and Actuator Nodes: Such as power seats, window lifters, mirror controls, and sunroofs.

Steering Column Modules: For controlling wipers, turn signals, and ignition.

Door Control Units: Managing locks, windows, and mirror adjustments.

Comfort and Convenience Systems: Including seat heating and climate control subsystems.

Essential Design Considerations

Successfully integrating the TLE7250LEXUMA1 requires attention to several key design aspects:

1. Power Supply and Decoupling: A stable and clean power supply is crucial. A decoupling capacitor (e.g., 100 nF) placed close to the Vbat pin is mandatory to suppress noise and ensure stable operation.

2. Bus Termination and Biasing: Proper termination is required at both ends of the LIN bus. The master node typically uses a 1 kΩ resistor in series with a diode and a pull-up resistor (e.g., 1 kΩ) to Vbat, while a slave node requires a pull-up resistor (typically 30 kΩ) to Vbat. A series resistor (e.g., 220 Ω) is also often used on the LIN pin for additional ESD protection.

3. PCB Layout: To minimize electromagnetic emissions (EME) and improve electromagnetic immunity (EMI), the LIN bus trace should be kept as short as possible and routed away from noisy or sensitive circuits. A ground plane beneath the IC is highly recommended.

4. Wake-up and Sleep Management: The system firmware must correctly manage the transition between normal, standby, and sleep modes to achieve the lowest possible power consumption. Proper handling of the EN (enable) pin and wake-up interrupt signals is essential.

5. Thermal Management: Although the device includes over-temperature protection, ensuring adequate copper area for the exposed thermal pad (EP) on the PCB will help dissipate heat and improve long-term reliability.

ICGOOODFIND

The Infineon TLE7250LEXUMA1 establishes itself as a robust and highly efficient solution for LIN network implementation. Its exceptional low-power performance, comprehensive suite of protective features, and full compliance with automotive standards make it an indispensable component for designers building reliable and power-efficient electronic control units. For engineers sourcing components, it represents a top-tier choice from a leading semiconductor manufacturer, promising quality and longevity in harsh automotive environments.

Keywords: LIN Transceiver, Automotive Networking, Low Quiescent Current, ESD Protection, TLE7250LEXUMA1