NXP Semiconductors UJA1076TW/3V3/WD,1

Overview

UJA1076TW/3V3/WD,1 from NXP Semiconductors is a high-speed CAN core System Basis Chip (SBC) integrating a 3.3 V/250 mA microcontroller voltage regulator, ISO 11898-2/5-compliant CAN transceiver, advanced window/timeout watchdog with on-chip oscillator, SPI interface, dual local wake-up inputs, and limp-home output - designed for automotive ECU power and communication management.

For engineers reviewing the UJA1076TW/3V3/WD,1 datasheet, UJA1076TW/3V3/WD,1 pinout, UJA1076TW/3V3/WD,1 application, or UJA1076TW/3V3/WD,1 equivalent, key selection considerations include 3.3 V regulator accuracy (±2 %), CAN bus short-circuit robustness (±58 V), HBM ESD rating (±8 kV on CAN/wake pins), HTSSOP32 thermal performance, and SPI-configurable watchdog timing (128 ms default period).

Technical Context

The UJA1076TW/3V3/WD,1 implements a state-machine-based system controller managing Off/Standby/Normal/Sleep/Overtemp modes with deterministic transitions triggered by VBAT thresholds, wake events, or temperature faults. Its dual-regulator architecture isolates V1 (3.3 V for MCU) from V2 (5 V for CAN transceiver), enabling independent undervoltage monitoring and fault reporting via SPI-accessible status registers.

Watchdog operation is decoupled from V1/V2 supplies via an internal VBAT-powered oscillator and supports three distinct modes: Window mode (reset on early/late trigger or overflow), Timeout mode (cyclic interrupt + reset on overflow with pending CI), and Off mode (WDOFF HIGH or WMC=1 in Standby). Wake-up sources include CAN bus activity, WAKE1/WAKE2 inputs with configurable sampling (16/64 ms), and cyclic wake capability.

Key Specifications

Pinout & Package

Package: HTSSOP32 (SOT549-1), 6.1 mm × 11 mm body, 0.65 mm pitch, exposed die pad for PCB thermal dissipation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar CAN SBC applications.

Compared with TJA1043TK/3 and UJA1075TW/3V3/WD,1, the UJA1076TW/3V3/WD,1 uniquely integrates full ECU power management, dual-regulator isolation, and SPLIT-enabled CAN bus stabilization - reducing component count and improving system-level EMC in complex automotive nodes.

Availability

UJA1076TW/3V3/WD,1 is available at Aetrix Electronics and suitable for automotive Body Control Modules, Engine Control Units, ADAS sensor hubs, and Electric Power Steering ECUs requiring stable component supply, long-lifecycle support, and AEC-Q100 qualified reliability.

Supply support for UJA1076TW/3V3/WD,1 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

NXP Semiconductors is a global semiconductor leader specializing in secure connectivity solutions for automotive, industrial, and IoT applications, with deep expertise in CAN, SBC, and automotive power management ICs.

The UJA1076TW/3V3/WD,1 belongs to NXP's System Basis Chip product line, engineered specifically for automotive electronic control units requiring integrated high-speed CAN communication, robust power regulation, and fail-safe system supervision.

FAQ

What is the nominal output voltage and accuracy of the main regulator in UJA1076TW/3V3/WD,1?

The UJA1076TW/3V3/WD,1 features a 3.3 V main voltage regulator (V1) with ±2 % output accuracy across temperature and load. This precision ensures reliable operation of connected microcontrollers and peripherals without requiring external trimming. The regulator delivers up to 250 mA and supports extension with an external PNP transistor for higher current demands and improved thermal distribution on the PCB.

Does UJA1076TW/3V3/WD,1 support both Window and Timeout modes for its watchdog function?

Yes, the UJA1076TW/3V3/WD,1 supports both Window and Timeout watchdog modes, selectable via the WMC bit in the WD_and_Status register. In Window mode, it resets the system if triggered too early or too late within the programmed period (default 128 ms). In Timeout mode, it generates a cyclic interrupt on overflow and performs a reset if the interrupt remains pending - providing flexible safety supervision tailored to different MCU firmware architectures.

How does the UJA1076TW/3V3/WD,1 handle wake-up events from the CAN bus and local inputs?

The UJA1076TW/3V3/WD,1 detects wake-up events from both the CAN bus (via RXDC) and two dedicated local inputs (WAKE1 and WAKE2). Wake sources are individually configurable for edge sensitivity and sampling timing (16 ms or 64 ms) using the Int_Control register. Status is reported in real time through the Int_Status register, and wake interrupts can be enabled or masked independently - enabling selective low-power operation in Standby or Sleep modes.

What is the purpose of the SPLIT pin on UJA1076TW/3V3/WD,1 and how is it used?

Pin 24 (SPLIT) on the UJA1076TW/3V3/WD,1 stabilizes the recessive common-mode voltage on split-terminated CAN bus topologies. It connects to the midpoint of a resistive divider between CANH and CANL, reducing bus reflections and improving signal integrity - especially in longer or branched networks. This feature enhances EMC performance and supports compliance with ISO 11898-2 requirements for high-speed CAN physical layer stability.

Can UJA1076TW/3V3/WD,1 operate during automotive cranking conditions?

Yes, the UJA1076TW/3V3/WD,1 operates reliably during cranking, supporting VBAT down to 4.5 V for the main regulator (V1) and 5.5 V for the CAN transceiver regulator (V2), in accordance with ISO 7637-2 pulse 4/4b and ISO 16750-2 specifications. Its undervoltage detection thresholds (90 % of nominal) and hysteresis ensure stable reset behavior and continuous monitoring even under severe battery sag conditions typical in start-stop systems.