UJA1078ATW/5V0WD,1

Specialized Overview

The UJA1078ATW/5V0WD,1 is a System Basis Chip (SBC) from NXP Semiconductors designed for automotive Electronic Control Units. It integrates a high-speed CAN transceiver compliant with ISO 11898-2 and ISO 11898-5 standards, alongside two LIN transceivers supporting LIN 2.2A and SAE J2602 protocols. The device features a scalable 5 V main voltage regulator delivering up to 250 mA for microcontroller supply, extendable via an external PNP transistor. A dedicated 5 V regulator powers the on-board CAN transceiver independently. Key functional blocks include a programmable watchdog with window and timeout modes, a full-duplex SPI interface for configuration, two local wake-up ports, and a limp home output port. The component operates within a temperature range of -40 °C to +125 °C and is housed in a 32-lead HTSSOP package.

Specialized Feature Summary

• Integrates high-speed CAN and dual LIN transceivers with enhanced EMC performance and robust ESD protection.
• Features a scalable 5 V voltage regulator capable of supplying up to 250 mA, with options for external current extension.
• Includes an advanced independent watchdog with configurable window and timeout modes supported by an on-chip oscillator.
• Provides comprehensive power management with multiple operating modes including standby, sleep, and overtemperature shutdown.

Specialized Applications

• Automotive Electronic Control Units (ECU) requiring integrated networking and power management
• Sensor peripheral control systems utilizing CAN as the main network interface
• Power distribution units managing local sub-busses via LIN interfaces

Specialized Procurement Notes

Verify the specific ordering suffix against the manufacturer's official documentation to confirm regulatory compliance and feature set. Ensure the selected variant matches the required voltage regulator output and presence of the watchdog function. Cross-reference the package type and thermal specifications with your PCB layout requirements before finalizing procurement orders.

Specialized Selection Notes

Select this component when a single-chip solution is required to replace discrete CAN/LIN transceivers and power regulators in automotive ECUs. Consider the 5 V regulator version if the microcontroller requires a 5 V supply. Evaluate the need for the watchdog feature, indicated by the 'WD' suffix, for safety-critical applications. Verify compatibility with the target microcontroller's SPI interface and reset requirements.

Specialized Part Context

The UJA1078A belongs to NXP's core System Basis Chip family, designed to simplify ECU design by integrating common functions into one package. It serves as a central hub for communication and power management, replacing multiple discrete components. This integration reduces board space and improves system reliability compared to traditional discrete implementations.

Specialized Replacement Considerations

The datasheet notes downward compatibility with the TJA1042 CAN transceiver but does not list direct pin-to-pin replacement part numbers for the entire SBC. Verify electrical parameters and pinout compatibility carefully if substituting with other SBCs from different manufacturers or families.

Specialized FAQ

What is the maximum current output of the main voltage regulator?

The main voltage regulator (V1) can deliver up to 250 mA. This capacity can be extended using an external PNP transistor for increased current capability and better heat distribution.

Does the UJA1078ATW/5V0WD,1 include a watchdog timer?

Yes, variants with the 'WD' suffix contain an advanced independent watchdog. It supports Window, Timeout, and Off modes and is clocked by an on-chip oscillator.

How many LIN interfaces are integrated into this chip?

The UJA1078A integrates two LIN transceivers, allowing it to support two local LIN sub-busses in addition to the main high-speed CAN interface.