NXP Semiconductors UJA1131HW/3V3Y

Overview

UJA1131HW/3V3Y from NXP Semiconductors is a buck/boost System Basis Chip (SBC) for automotive ECUs, integrating a 3.3 V/500 mA LDO (V1), ISO 11898-2-compliant HS-CAN transceiver supporting up to 2 Mbit/s CAN FD data fields, dual LIN transceivers, and a switch-mode power supply with automatic buck/boost mode selection. It delivers fail-safe operation via watchdog, limp-home outputs, and non-volatile configuration memory - deployed in engine control modules requiring robust low-voltage resilience down to 2 V.

For engineers reviewing the UJA1131HW/3V3Y datasheet, UJA1131HW/3V3Y pinout, UJA1131HW/3V3Y application, or UJA1131HW/3V3Y equivalent, this page provides verified technical context, validated pin functions, confirmed automotive-grade specifications, and real-world ECU deployment constraints - including battery dip tolerance, CAN FD passive compatibility limits, and HVIO diagnostic capability.

Technical Context

The UJA1131HW/3V3Y implements a fully autonomous SMPS that dynamically selects buck or boost mode based on input voltage (BAT) and load conditions, enabling continuous microcontroller supply during battery dips as low as 2 V. Its CAN transceiver complies with ISO 11898-2:201x and supports CAN FD fast-phase communication at up to 2 Mbit/s, with loop delay symmetry meeting upcoming CAN FD timing requirements.

This variant includes two LIN transceivers compliant with SAE J2602 and LIN 2.x, four configurable HVIOs (HS/LS/wake-up), a 10-bit battery A/D converter with dual-channel monitoring, and SPI-configurable power modes (Normal, Standby, Sleep). Non-volatile memory stores limp-home behavior, wake thresholds, and SMPS pre-regulator voltage settings - critical for ASIL-B–aligned ECU designs.

Key Specifications

Pinout & Package

UJA1131HW/3V3Y uses the HTQFP48 package (SOT1181-2), with 48 leads, 10 mm × 10 mm body, 1.0 mm height, and an exposed die pad internally connected to GND for enhanced thermal dissipation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar System Basis Chip applications.

Compared with UJA1132HW/3V3, the UJA1131HW/3V3Y offers identical core functionality but with coarser limp-home timer resolution; versus TLE9471-2ES, it delivers native boost-down to 2 V and integrated HVIOs - eliminating external components and enabling true limp-home autonomy in severe cranking conditions.

Availability

UJA1131HW/3V3Y is available at Aetrix Electronics and suitable for engine control units, transmission control modules, body control modules, and ADAS ECUs requiring stable component supply across automotive production lifecycles.

Supply support for UJA1131HW/3V3Y 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 ASIL-compliant power management and vehicle networking.

The UJA113x product line was designed specifically for next-generation automotive ECUs needing integrated power, CAN/LIN connectivity, and fail-safe features in a single compact package - targeting ASIL-B functional safety compliance without external supervision.

FAQ

What is the minimum battery voltage at which UJA1131HW/3V3Y can sustain 3.3 V MCU supply?

The UJA1131HW/3V3Y maintains regulated 3.3 V output down to 2 V battery voltage using its integrated boost converter. This capability is confirmed in the datasheet Section 2.2 and enables uninterrupted MCU operation during engine cranking events where battery dips occur. The actual minimum sustainable voltage depends on load current, but 2 V is the guaranteed operational floor under typical conditions. UJA1131HW/3V3Y achieves this without external boost components - only a single coil and capacitors are required.

Does UJA1131HW/3V3Y support CAN FD partial networking with CAN FD-passive wake-up?

No, UJA1131HW/3V3Y does not support CAN FD-passive wake-up or ISO 11898-6:2013–compliant partial networking. That feature is exclusive to UJA113xFD/x variants (e.g., UJA1131HW/FD/3V/4). UJA1131HW/3V3Y supports classic CAN partial networking only, meaning it will wake on any CAN traffic - including CAN FD frames - which may cause unintended wake-ups in mixed FD/classic networks. UJA1131HW/3V3Y remains fully compatible with CAN FD data-field communication up to 2 Mbit/s.

How many LIN transceivers does UJA1131HW/3V3Y integrate, and are they independently configurable?

UJA1131HW/3V3Y integrates two fully independent LIN 2.x–compliant transceivers (LIN1 and LIN2), both meeting SAE J2602 and backward-compatible with LIN 1.3. Each has dedicated TXDL/RXDL pins and supports separate slave termination. LIN2 functionality is enabled per family documentation (Table 1), and both channels operate concurrently - allowing simultaneous communication with multiple LIN clusters (e.g., front and rear lighting modules). UJA1131HW/3V3Y does not require external LIN transceivers or termination resistors.

What diagnostic capabilities does UJA1131HW/3V3Y provide for its HVIOs?

UJA1131HW/3V3Y provides comprehensive HVIO diagnostics: open-load detection, short-to-battery/short-to-ground protection with reporting, and configurable undervoltage/overvoltage shutdown. Each of the four HVIOs (HVIO1–HVIO4) reports fault status via SPI, and individual wake-up thresholds (ratiometric or absolute) are programmable. Diagnostics operate continuously in Normal mode and during cyclic sampling in Standby - critical for validating solenoid or relay health in safety-critical ECUs. UJA1131HW/3V3Y also supports combined HVIO banks for higher current drive.

Is the SMPS of UJA1131HW/3V3Y configurable to supply external loads directly?

Yes, the SMPS of UJA1131HW/3V3Y can supply external loads directly - for example, as an energy-efficient source for LED chains or auxiliary actuators. Its VSMPS output (pin 47) delivers up to 1.2 A with adjustable pre-regulator voltage via SPI. When used externally, the SMPS operates independently of V1/V2 regulators, maintaining high efficiency across wide input/output ranges. This capability is documented in Section 2.2 and eliminates the need for additional DC-DC converters in multi-rail ECU designs. UJA1131HW/3V3Y supports this without compromising MCU supply stability.