STMicroelectronics STM32L031C6U3

Overview

STM32L031C6U3 from STMicroelectronics is an ultra-low-power 32-bit Arm® Cortex®-M0+ microcontroller in UFQFPN28 (4×4 mm) package, featuring 32 KB Flash with ECC, 8 KB SRAM, 1 KB EEPROM with ECC, 12-bit ADC (1.14 Msps, 10-channel), and dual ultra-low-power comparators. It operates from 1.65–3.6 V across –40 to +125 °C and targets battery-powered sensor nodes and smart meters requiring sub-µA standby current (0.23 µA) and fast 5 µs wakeup from Flash.

For engineers reviewing the STM32L031C6U3 datasheet, STM32L031C6U3 pinout, STM32L031C6U3 application, or STM32L031C6U3 equivalent, key selection criteria include verified low-power mode timing (Stop: 0.35 µA, Standby: 0.23 µA), 31 I/Os with 5V tolerance, integrated RTC with 8 KB RAM retention, and pre-programmed USART/SPI bootloader support.

Technical Context

The STM32L031C6U3 implements a single-core Arm Cortex-M0+ running at up to 32 MHz with 0.95 DMIPS/MHz performance, supported by dynamic voltage scaling and multiple clock sources: HSI16 (±1%), LSE (32 kHz for RTC), MSI (65 kHz–4.2 MHz), and external crystal (1–25 MHz). Its interconnect matrix routes peripherals-including ADC, timers, and communication interfaces-directly to the AHB/LP bus without arbitration overhead.

Power management integrates ultra-low-power BOR with five threshold levels, programmable voltage detector (PVD), and POR/PDR circuitry enabling robust operation down to 1.65 V. Low-power modes are hardware-automated: Standby retains only RTC and 20-byte backup registers; Stop mode preserves full 8 KB SRAM with RTC active; Run mode delivers 76 µA/MHz efficiency at 3.3 V.

Key Specifications

Pinout & Package

STM32L031C6U3 is housed in a 28-pin Ultra-Fine Pitch Quad Flat No-lead (UFQFPN28) package measuring 4 × 4 mm with 0.5 mm pitch, optimized for space-constrained PCB layouts and automated assembly. The package complies with ECOPACK®2 environmental standards.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar ultra-low-power MCU applications.

Compared with STM32L011K4T6, the STM32L031C6U3 offers double Flash, double SRAM, and integrated EEPROM-critical for firmware resilience and parameter persistence-while matching its ultra-low-power profile; versus STM32L051C8T6, it trades USB and extra memory for smaller 28-pin footprint and lower system-level BOM cost.

Availability

STM32L031C6U3 is available at Aetrix Electronics and suitable for smart utility metering, wireless sensor nodes, portable medical devices, and asset tracking tags requiring stable component supply, long-term lifecycle assurance, and consistent parametric performance across temperature extremes.

Supply support for STM32L031C6U3 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing microcontrollers, power ICs, sensors, and analog products for industrial, automotive, and consumer markets.

The STM32L0 series targets ultra-low-power embedded applications demanding multi-year battery life, robust operation across wide temperature ranges, and integrated analog peripherals-enabling compact, self-contained IoT edge nodes without external support components.

FAQ

What is the maximum operating frequency and core architecture of the STM32L031C6U3?

The STM32L031C6U3 features an Arm Cortex-M0+ core rated for up to 32 MHz operation, delivering 0.95 DMIPS per MHz. It supports dynamic voltage scaling to optimize power vs. performance and includes a 16 MHz factory-trimmed internal RC oscillator with ±1% accuracy over temperature and voltage.

Does the STM32L031C6U3 support hardware error correction for Flash and EEPROM?

Yes, the STM32L031C6U3 includes built-in ECC (Error Correction Code) for both its 32 KB Flash memory and 1 KB data EEPROM. This ensures bit-error resilience during program/erase cycles and long-term data retention, critical for firmware integrity and nonvolatile parameter storage in mission-critical applications.

How many I/O pins are 5V tolerant, and what is the package type?

The STM32L031C6U3 provides 31 of its 38 fast I/Os with 5V tolerance, allowing direct interfacing with legacy 5V peripherals without external level shifters. It is packaged in a 28-pin UFQFPN (Ultra-Fine Pitch Quad Flat No-lead) measuring 4 × 4 mm with 0.5 mm pitch and ECOPACK®2 compliance.

Can the STM32L031C6U3 operate from a single-cell Li-SOCl₂ battery?

Yes-the STM32L031C6U3 operates across 1.65 V to 3.6 V, fully covering the discharge curve of a primary lithium thionyl chloride (Li-SOCl₂) cell (nominal 3.6 V, end-of-life ~2.0 V). Its 0.23 µA Standby current and RTC functionality enable decade-scale operation in infrequently waking applications.