NXP Semiconductors UJA1076ATW/3V3WD,1

Overview

UJA1076ATW/3V3WD,1 from NXP Semiconductors is a high-speed CAN core System Basis Chip (SBC) integrating a 3.3 V/250 mA microcontroller voltage regulator (V1), a dedicated 5 V CAN transceiver regulator (V2), ISO 11898-2/5-compliant CAN transceiver, SPI interface, dual local wake-up inputs, limp home output, and advanced watchdog with Window/Timeout modes. It replaces discrete ECU power, interface, and safety functions in automotive body control modules and gateway ECUs.

For engineers reviewing the UJA1076ATW/3V3WD,1 datasheet, UJA1076ATW/3V3WD,1 pinout, UJA1076ATW/3V3WD,1 application, or UJA1076ATW/3V3WD,1 equivalent, key selection considerations include its 3.3 V V1 regulator accuracy (±2 %), ±58 V short-circuit protected CAN bus pins, HTSSOP32 thermal-enhanced package, watchdog programmability via SPI, and support for remote flash programming over CAN.

Technical Context

The UJA1076ATW/3V3WD,1 implements a state-machine-based system controller managing Off/Standby/Normal/Sleep/Overtemp mode transitions triggered by VBAT thresholds, wake events, or register writes. Its CAN transceiver features SPLIT pin for recessive bus stabilization and floating bus pins in Off mode per ISO 11898-5.

Power management includes dual regulators: V1 (3.3 V, ±2 %, 250 mA, extendable with external PNP) and V2 (5 V, switchable, undervoltage warning at 90 %). Wake-up sources-CAN activity, WAKE1/WAKE2 inputs, and cyclic timer-are detectable and reportable via SPI registers including WD_and_Status and Int_Status.

Key Specifications

Pinout & Package

UJA1076ATW/3V3WD,1 uses the HTSSOP32 (SOT549-1) package: plastic thermal enhanced thin shrink small outline, 32 leads, 6.1 mm body width, 0.65 mm lead pitch, and exposed center die pad soldered to PCB ground for optimal thermal and electrical performance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TJA1043T/CM,118 and UJA1075ATW/3V3,1, the UJA1076ATW/3V3WD,1 uniquely combines 3.3 V regulation, dual wake-up, limp home, and programmable watchdog in HTSSOP32-enabling single-chip ECU designs meeting ISO 26262 ASIL-B system-level requirements without layout changes.

Availability

UJA1076ATW/3V3WD,1 is available at Aetrix Electronics and suitable for automotive body control modules, gateway ECUs, and engine control units requiring stable component supply, long-term lifecycle support, and AEC-Q100 qualified reliability.

Supply support for UJA1076ATW/3V3WD,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 functional safety technologies.

The UJA1076A product line delivers integrated System Basis Chips designed specifically for automotive ECU power management, communication, and fail-safe operation-targeting ASIL-B compliant systems with minimal external components.

FAQ

What is the nominal output voltage and accuracy of the main regulator (V1) in UJA1076ATW/3V3WD,1?

The UJA1076ATW/3V3WD,1 features a 3.3 V main voltage regulator (V1) with ±2 % output voltage accuracy across temperature and load. This precision ensures reliable operation of connected microcontrollers and peripherals under automotive conditions, including battery cranking down to 4.5 V. The UJA1076ATW/3V3WD,1 maintains this accuracy without external trimming components.

Does UJA1076ATW/3V3WD,1 support remote firmware updates over the CAN bus?

Yes, the UJA1076ATW/3V3WD,1 explicitly supports remote flash programming via the CAN bus as stated in its official product data sheet. Its integrated high-speed CAN transceiver, robust bus protection (±58 V short-circuit, ISO 7637-3), and controlled power sequencing enable secure and reliable in-vehicle firmware updates without physical access.

How does the watchdog function differ between Window and Timeout modes in UJA1076ATW/3V3WD,1?

In Window mode, the UJA1076ATW/3V3WD,1 requires watchdog triggers within a defined time window (first half of period) to avoid reset; triggering too early or too late causes immediate reset. In Timeout mode, any trigger resets the timer, and overflow sets a cyclic interrupt flag-only causing reset if the flag was already pending. Both modes use the same on-chip oscillator and are programmable via SPI register bits WMC and NWP in the UJA1076ATW/3V3WD,1.

What is the purpose of the SPLIT pin on UJA1076ATW/3V3WD,1, and how is it used?

The SPLIT pin (Pin 24) on the UJA1076ATW/3V3WD,1 provides a stabilized common-mode voltage reference for split termination on the CAN bus. It connects to the midpoint of two 60 Ω resistors between CANH and CANL, reducing bus reflections and improving signal integrity-especially critical in noisy automotive environments. This feature is documented in Section 2.2 and Figure 1 of the UJA1076ATW/3V3WD,1 datasheet.

Can UJA1076ATW/3V3WD,1 operate with VBAT below 5 V, and what is its minimum functional voltage?

Yes, the UJA1076ATW/3V3WD,1 operates with VBAT as low as 4.5 V for the V1 regulator (supporting cranking per ISO 7637 and ISO 16750-2), and 5.5 V for the V2 regulator. Its system controller remains functional down to 4.5 V, maintaining regulated 3.3 V output and CAN transceiver readiness-ensuring uninterrupted ECU operation during engine start. This specification is confirmed in Sections 2.5 and 6.1.2 of the UJA1076ATW/3V3WD,1 data sheet.