Infineon TLE7259-2GE LIN Transceiver: Key Features and Application Design Guide
The Infineon TLE7259-2GE is a highly integrated 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 robust and reliable communication in body control modules, sensor interfaces, and other sub-network applications, this IC stands out for its combination of performance, protection, and power efficiency.
Key Features of the TLE7259-2GE
The TLE7259-2GE is packed with features that make it a premier choice for automotive designers:
Compliance with LIN Standards: The device is fully compliant with the latest LIN 2.2/2.2A, SAE J2602, and ISO 17987-4 specifications, ensuring interoperability within standardized automotive networks.
Very Low Standby Current: A critical feature for automotive applications is its ultra-low current consumption in sleep mode, typically 7 µA. This is essential for meeting the strict quiescent current requirements of modern vehicles to prevent battery drain when the ignition is off.
Enhanced Electromagnetic Compatibility (EMC): The transceiver boasts excellent EMC performance, featuring a very high ESD robustness of up to ±6 kV according to the Human Body Model (HBM). It also includes improved ESD handling on the LIN bus pin, safeguarding the system against electrostatic discharges.
Comprehensive Protection Functions: Built-in protection mechanisms include over-temperature shutdown, supply voltage undervoltage detection, and a permanent dominant detection timer. The LIN bus pin is protected against transients in the automotive environment (e.g., load dump) and is short-circuit proof to battery and ground.
Wake-up Source Recognition: The device can be woken up by either a local wake-up via the WAKE/NMI pin or a remote wake-up via the LIN bus, providing flexibility in system design for various wake-up scenarios.
Green Product (RoHS compliant): The TLE7259-2GE is offered in a leadless PG-SSO-14-13 package, which is optimized for automated assembly and meets environmental standards.
Application Design Guide
Implementing the TLE7259-2GE effectively requires attention to several key design aspects:
1. Power Supply and Decoupling: A stable and clean power supply is paramount. A decoupling capacitor (e.g., 100 nF) placed close to the VSUP pin is mandatory to filter high-frequency noise. A larger bulk capacitor (e.g., 10 µF to 47 µF) may be required to handle voltage dips and ensure stable operation during load transients.
2. LIN Bus Interface: The LIN bus line should be properly terminated. A series resistor (e.g., 1 kΩ) is recommended between the TXD pin and the microcontroller to limit current and dampen oscillations. The LIN bus requires a pull-up resistor (typically 1 kΩ) and a series diode to the battery (VSUP), as specified in the LIN standard. A common-mode choke (CMC) on the bus line is highly recommended to suppress common-mode noise and improve EMC performance.
3. Grounding: A solid, low-impedance ground connection is crucial for signal integrity and noise immunity. Ensure the GND pin has a direct and low-inductance path to the system ground plane.
4. Wake-up Management: To minimize power consumption, the system microcontroller should put the TLE7259-2GE into low-power sleep mode when communication is not required. The WAKE/NMI pin can be configured to generate a non-maskable interrupt to the microcontroller upon a wake-up event, triggering the system to resume normal operation.
5. PCB Layout: For optimal EMC/EMI performance, keep the traces between the transceiver and the microcontroller (TXD, RXD) as short as possible. The area of the loop formed by the LIN bus traces should be minimized to reduce electromagnetic emissions. The use of a ground plane beneath the IC is strongly advised.
The Infineon TLE7259-2GE establishes itself as a robust and reliable cornerstone for LIN network design. Its exceptional low-power performance, comprehensive suite of protective features, and strong compliance with automotive standards make it an ideal solution for a wide array of in-vehicle applications, from comfort electronics to intelligent sensors, ensuring dependable communication while enhancing overall system energy efficiency.
Keywords: LIN Transceiver, Low Standby Current, ESD Protection, Automotive Networking, Wake-up Recognition
