STMicroelectronics STM32L031G6U6

Overview

STM32L031G6U6 from STMicroelectronics is an ultra-low-power 32-bit Arm® Cortex®-M0+ microcontroller in UFQFPN28 (4×4 mm) package, featuring 32 KB Flash, 8 KB SRAM, 1 KB EEPROM with ECC, 12-bit ADC (1.14 Msps), 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 metering endpoints.

For engineers reviewing the STM32L031G6U6 datasheet, STM32L031G6U6 pinout, STM32L031G6U6 application, or STM32L031G6U6 equivalent, key selection criteria include standby current (0.23 µA), RTC-enabled stop mode (0.6 µA), 5 µs Flash wakeup time, and 31 I/Os with 5V tolerance - critical for energy-constrained industrial and IoT edge devices.

Technical Context

The STM32L031G6U6 integrates a Cortex-M0+ core running up to 32 MHz with 0.95 DMIPS/MHz performance, supported by multiple clock sources: 16 MHz factory-trimmed HSI (±1%), 32 kHz LSE for RTC calibration, and PLL for CPU clock scaling. Its low-power architecture includes five operational modes (Run, Sleep, Low-power Run, Stop, Standby), each with distinct peripheral retention and wakeup latency profiles.

Memory subsystem includes ECC-protected Flash and EEPROM, 20-byte backup registers, and sector write protection. Analog peripherals are optimized for sub-2 V operation: ADC functions down to 1.65 V with 10-channel support, and two comparators with window mode and wake-up capability - enabling precise threshold monitoring without CPU intervention.

Key Specifications

Pinout & Package

STM32L031G6U6 uses the UFQFPN28 (4 × 4 mm, 0.5 mm pitch) package with 28 terminals, optimized for space-constrained PCB layouts in portable and embedded applications.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STM32L031G6U6, STM32L011K4T6 trades EEPROM and Flash capacity for lower unit cost, while EFM32ZG108F16 offers faster ADC sampling at the expense of programmable memory and ecosystem tooling maturity - making STM32L031G6U6 optimal for balanced, production-ready ultra-low-power designs requiring firmware extensibility and data integrity.

Availability

STM32L031G6U6 is available at Aetrix Electronics and suitable for smart metering, wireless sensor networks, portable medical devices, and asset tracking beacons requiring stable component supply across multi-year production cycles.

Supply support for STM32L031G6U6 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 management ICs, sensors, and analog components for industrial, automotive, and consumer markets.

The STM32L0 series targets ultra-low-power embedded applications demanding extended battery life, robust security features, and seamless integration with ST's CubeMX and HAL ecosystem - specifically engineered for IoT edge nodes and energy-harvesting systems.

FAQ

What is the maximum operating frequency and core type of the STM32L031G6U6?

The STM32L031G6U6 features an Arm Cortex-M0+ core with a maximum CPU frequency of 32 MHz. It delivers 0.95 DMIPS/MHz performance and supports dynamic voltage scaling to optimize power versus speed. The core includes a single-cycle multiplier, nested vectored interrupt controller (NVIC), and SysTick timer - all essential for deterministic real-time execution in resource-constrained environments.

Does the STM32L031G6U6 support hardware encryption or secure boot?

No, the STM32L031G6U6 does not integrate hardware cryptographic accelerators (AES, SHA, PKA) or secure boot functionality. It relies on software-based security measures and external secure elements for advanced authentication or encrypted firmware updates. For applications requiring built-in crypto, ST recommends the STM32L4 or STM32L5 series, which include AES-128/256 engines and secure ROM-based bootloaders.

How many I/O pins are 5V tolerant, and what is the maximum number usable simultaneously?

31 I/O pins (PA0–PA15, PB0–PB12, PC13–PC15) are 5V tolerant on the STM32L031G6U6. All 31 can be used simultaneously as general-purpose inputs/outputs, provided VDD remains within 1.65–3.6 V. This tolerance allows direct interfacing with legacy 5V logic, RS-232 level shifters, or industrial sensors without external voltage translators - reducing system complexity and bill-of-materials cost.

What debug interfaces are supported, and is SWD available on the UFQFPN28 package?

The STM32L031G6U6 supports Serial Wire Debug (SWD) only - no JTAG. On the UFQFPN28 package, SWD is implemented on pins PA13 (SWDIO) and PA14 (SWCLK), both accessible on the outer row of the 28-pin footprint. These pins are dedicated to debug and cannot be reassigned to other functions during active debugging, but may be reused as GPIO after debug initialization if SWD is disabled in software.