NXP Semiconductors UJA1076ATW/3V3,112

Overview

UJA1076ATW/3V3,112 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 supply (V2), ISO 11898-2/5-compliant high-speed CAN transceiver, SPI interface, dual local wake-up inputs, and limp home output - designed for automotive ECU power management and network interface consolidation.

For engineers reviewing the UJA1076ATW/3V3,112 datasheet, UJA1076ATW/3V3,112 pinout, UJA1076ATW/3V3,112 application, or UJA1076ATW/3V3,112 equivalent, this page delivers verified functional architecture, regulator accuracy (±2 %), thermal shutdown behavior, watchdog timing modes (128 ms default), and HTSSOP32 package-level design constraints critical for automotive ECU start-up sequencing and fail-safe operation.

Technical Context

The UJA1076ATW/3V3,112 implements a state-machine-based system controller managing Off/Standby/Normal/Sleep/Overtemp mode transitions triggered by VBAT thresholds, wake events, or register-controlled MC bits. Its dual-regulator architecture isolates V1 (3.3 V, ±2 %, 250 mA) for MCU/peripherals from V2 (5 V) for the CAN transceiver - enabling independent undervoltage detection (90 % Vuvd) and cranking resilience down to 4.5 V (V1) and 5.5 V (V2).

SPI communication uses full-duplex 16-bit framing with register-mapped control (WD_and_Status, Mode_Control, Int_Control), while the CAN transceiver supports bus-floating in Off mode, SPLIT pin for recessive level stabilization, and ±58 V short-circuit protection on CANH/CANL - all compliant with ISO 7637-3 transient immunity and IEC 61000-4-2 ±6 kV ESD.

Key Specifications

Pinout & Package

HTSSOP32 package (SOT549-1) with 32 leads, 6.1 mm body width, 0.65 mm lead pitch, and thermally enhanced exposed die pad soldered to PCB ground per datasheet recommendation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TJA1043TK/3 and UJA1075ATW/3V3,112, the UJA1076ATW/3V3,112 uniquely integrates limp home output, external PNP regulator extension, and programmable watchdog with window mode - making it the only option among the three qualified for ASIL-B-compliant power management in safety-critical ECUs.

Availability

UJA1076ATW/3V3,112 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 across extended temperature ranges (−40 °C to +150 °C) and long lifecycle commitments.

Supply support for UJA1076ATW/3V3,112 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 architectures.

The UJA1076ATW/3V3,112 belongs to NXP's System Basis Chip product line, engineered specifically to consolidate power management, communication interface, and safety monitoring functions into a single automotive-qualified IC for ECU miniaturization and ASIL-B compliance.

FAQ

What is the nominal output voltage and accuracy of the main regulator (V1) in UJA1076ATW/3V3,112?

The UJA1076ATW/3V3,112 features a 3.3 V main voltage regulator (V1) with ±2 % output accuracy across temperature and load conditions. This precision ensures reliable operation of connected microcontrollers and peripherals, especially during battery cranking events where VBAT drops to 4.5 V - a key requirement for automotive ECU certification per ISO 16750-2.

Does UJA1076ATW/3V3,112 support external extension of its V1 regulator current capability?

Yes, the UJA1076ATW/3V3,112 supports external current extension of its 3.3 V V1 regulator using an external PNP transistor connected via VEXCTRL (base control) and VEXCC (collector current sense) pins. The activation threshold is programmable (50 mA or 85 mA), enabling thermal load distribution across the PCB - a critical feature for high-current ECUs where on-die dissipation must be minimized.

How does the watchdog function in UJA1076ATW/3V3,112 differ from basic timeout-only implementations?

The UJA1076ATW/3V3,112 watchdog supports Window, Timeout, and Off modes - with Window mode requiring trigger events within a defined time window (first half of period) to prevent reset. This prevents both early and late software hangs, unlike simple timeout watchdogs. Its default 128 ms period is configurable (8–4096 ms), and it uses an independent on-chip oscillator, ensuring reliability even if V1/V2 are unstable.

What safety-critical outputs does UJA1076ATW/3V3,112 provide for automotive fail-operational design?

The UJA1076ATW/3V3,112 provides two hardware-enforced safety outputs: EN (enable) for controlling external safety-critical circuitry and LIMP (limp home) - an active-low open-drain output asserted during overtemperature events or software-triggered faults. Both are directly tied to internal fault monitors and require no MCU intervention, fulfilling ASIL-B requirements for autonomous fault response.

Is UJA1076ATW/3V3,112 compatible with ISO 11898-5 for fault-tolerant CAN networks?

Yes, the UJA1076ATW/3V3,112 high-speed CAN transceiver is explicitly compliant with both ISO 11898-2:2003 and ISO 11898-5:2006 standards. ISO 11898-5 defines fault-tolerant physical layer requirements for automotive CAN, including bus-off recovery, dominant timeout, and improved electromagnetic compatibility - all supported by the UJA1076ATW/3V3,112 transceiver architecture.