NXP TJA1048TK,118 High-Speed CAN Transceiver: Datasheet, Features, and Application Circuit Design
The NXP TJA1048TK,118 is a high-speed Controller Area Network (CAN) transceiver serving as the critical interface between a CAN protocol controller and the physical two-wire CAN bus. Complying with the ISO 11898-2:2016 standard, it is engineered for robust performance in automotive and industrial applications where electromagnetic compatibility (EMC) and electrostatic discharge (ESD) protection are paramount.
Key Features and Datasheet Overview
The TJA1048TK,118 belongs to NXP's third generation of high-speed CAN transceivers, offering significant improvements over its predecessors. Its standout features, as detailed in its datasheet, include:
Very Low Power Consumption: It features multiple low-power modes, including a Standby mode with local and remote wake-up capability and a Sleep mode with extremely low quiescent current. This is crucial for automotive applications requiring compliance with strict energy consumption standards.
Excellent EMC Performance: The device is designed to minimize electromagnetic emissions and provides high immunity to electromagnetic interference, ensuring reliable communication in noisy environments.
High ESD Robustness: It offers superior protection, with ±8 kV ESD protection (according to IEC 61000-4-2) on the CAN bus pins, safeguarding the IC and the wider network from transient events.
Fail-Safe Features: The transceiver supports undervoltage detection on the VCC supply and will disconnect the CAN bus in case of a loss of power, preventing the node from loading the network.
Silent Mode: This mode allows the CAN controller to monitor the bus traffic without influencing it, which is essential for node diagnosis and self-test during startup.
Small Package: The TJA1048TK,118 is offered in an HVSON8 package, making it suitable for space-constrained applications.
Typical Application Circuit Design
Implementing the TJA1048TK,118 in a CAN node design is straightforward. A typical application circuit includes the following key components and design considerations:
1. Microcontroller Interface: The transceiver connects directly to a CAN protocol controller (often integrated into a microcontroller) via the TXD (Transmit Data) and RXD (Receive Data) pins. A series resistor (e.g., 100Ω) on the RXD line is sometimes used to limit current.
2. Power Supply: The VCC pin is typically connected to a +5V supply, which must be well-regulated and decoupled. A 100 nF ceramic capacitor should be placed as close as possible between the VCC and GND pins to filter high-frequency noise.
3. Mode Control: The STB (Standby) pin controls the operating mode. Pulling this pin low puts the transceiver into Normal mode. Pulling it high activates Standby mode. This pin is controlled by the microcontroller for power management.
4. CAN Bus Lines: The CANH and CANL pins connect to the physical CAN bus. The bus must be terminated at both ends with 120Ω resistors to prevent signal reflections. The value of these resistors is critical for proper impedance matching.
5. Protection and Filtering: For enhanced robustness in harsh environments, additional external components are recommended:
Common-Mode Choke (CMC): Placed in series on the CANH and CANL lines, it significantly improves EMC performance by suppressing common-mode noise.
Transient Voltage Suppression (TVS) Diodes: Placed between CANH/GND and CANL/GND, these diodes clamp high-voltage transients (e.g., from load dump pulses) beyond the internal ESD protection limits.
Series Resistors: Small value resistors (e.g., 10-22Ω) in series with each bus line can help limit current during transient events and dampen ringing.
This combination of a robust IC and careful external circuit design ensures a highly reliable and fault-tolerant network node.
ICGOODFIND: The NXP TJA1048TK,118 stands out as an industry-leading high-speed CAN transceiver, delivering an optimal blend of ultra-low power management, exceptional robustness, and ease of integration, making it an ideal choice for next-generation automotive and industrial network architectures.
Keywords: CAN Transceiver, Low Power Mode, ESD Protection, Application Circuit, ISO 11898-2
