NXP TJA1021TK/20/C,118 LIN 2 Transceiver: Datasheet, Application Circuit, and Key Features

The NXP TJA1021TK/20/C,118 is a Local Interconnect Network (LIN) transceiver, serving as the physical layer interface between a LIN protocol controller and the LIN bus. This highly integrated device is engineered to support the latest LIN 2.x standards and is a cornerstone component in modern automotive networking for sub-systems like sensors, actuators, and door modules.

Key Features

The TJA1021 stands out due to its robust feature set tailored for the harsh automotive environment. Its low electromagnetic emission (EME) and high electromagnetic immunity (EMI) ensure reliable communication without interfering with other sensitive electronics. A critical feature is its very low current consumption in sleep mode, typically as low as 10 µA, which is essential for meeting the strict quiescent current requirements of always-connected automotive applications. The transceiver includes comprehensive protection mechanisms, such as bus terminal protection against automotive transients (e.g., load dump) and protection against loss of battery and ground. Furthermore, it supports baud rates up to 20 kbaud and is fully compliant with the LIN 2.0, LIN 2.1, LIN 2.2, and SAE J2602 standards.

Application Circuit

Implementing the TJA1021 is straightforward. The typical application circuit requires a minimal number of external components. The core connection involves:

Vbat Pin: Connected to the vehicle's battery voltage (typically 12V), often through a series resistor for additional protection.

LIN Pin: The bus line output, connected to the LIN network via a series resistor and often a diode for additional EMC performance.

TXD Pin: Connected to the transmit data output of the host microcontroller (LIN protocol controller).

RXD Pin: Connected to the receive data input of the host microcontroller.

WAKE/NMI Pin: Used to wake the local microcontroller from a low-power mode via a wake-up signal from the LIN bus.

A pull-up resistor and a series diode on the LIN bus line are common external components recommended to optimize performance and robustness. The specific values and layout are detailed in the datasheet and application notes to ensure signal integrity.

Datasheet Overview

The official datasheet is the ultimate source of truth for design-in. It provides detailed electrical characteristics, including absolute maximum ratings, DC parameters, and AC timing parameters crucial for timing analysis. It extensively covers the functional description of each operating mode (Normal, Sleep, Standby), the waveforms for wake-up and dominant time-out procedures, and application information with guidelines for PCB layout and EMC performance. For any serious design, consulting the datasheet is non-negotiable.

ICGOODFIND: The NXP TJA1021TK/20/C,118 is a highly reliable and efficient LIN transceiver that exemplifies modern automotive-grade design. Its ultra-low power sleep mode, extensive protective features, and compliance with key standards make it an ideal choice for cost-effective and robust body electronics and sensor networking in vehicles.

Keywords: LIN Transceiver, Automotive Networking, Low Power Consumption, EMC Protection, NXP Semiconductors