STMicroelectronics STM32L031G6U6S

Overview

STM32L031G6U6S 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 delivers 76 µA/MHz in Run mode - deployed in battery-powered sensor nodes and smart utility meters requiring long-term autonomous operation.

For engineers reviewing the STM32L031G6U6S datasheet, STM32L031G6U6S pinout, STM32L031G6U6S application, or STM32L031G6U6S equivalent, key selection criteria include standby current (0.23 µA), RTC-enabled Stop mode (0.6 µA with 8 KB RAM retention), 5 µs Flash wakeup time, and 31 I/Os with 5V tolerance - all critical for energy-constrained embedded control designs.

Technical Context

The STM32L031G6U6S integrates a Cortex-M0+ core running up to 32 MHz with dynamic voltage scaling, supported by multiple clock sources: 16 MHz factory-trimmed HSI (±1%), 32 kHz LSE for RTC calibration, and PLL for CPU clock generation. Its low-power architecture includes five operational modes (Run, Sleep, Low-power Run, Stop, Standby), each with distinct peripheral enablement and retention policies.

Peripheral interconnect is managed via an AHB/APB matrix supporting concurrent DMA transfers to ADC, USART, SPI, I²C, and timers. The device implements hardware ECC on Flash and EEPROM, 96-bit unique ID, CRC calculation unit, and serial wire debug (SW-DP) - enabling secure, traceable, and field-upgradable firmware deployment in industrial edge nodes.

Key Specifications

Pinout & Package

STM32L031G6U6S uses the UFQFPN28 (4 × 4 mm, 0.5 mm pitch) package with 28 terminals, optimized for space-constrained PCB layouts in wearables and IoT endpoints. Pin functions are validated per STMicroelectronics DS10668 Rev 6, Section 4 "Pin descriptions".

Key Features

Applications

Equivalent & Alternatives

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

Compared with STM32L031G6U6S, STM32L011K4T6 trades EEPROM and ADC channels for lower cost and smaller Flash, while EFM32ZG222F32 omits hardware memory protection and RTC-extended retention - making STM32L031G6U6S the sole option meeting simultaneous requirements for 10-year battery life, on-chip data integrity, and calibrated analog sensing.

Availability

STM32L031G6U6S is available at Aetrix Electronics and suitable for smart metering, portable medical devices, wireless sensor networks, and asset tracking tags requiring stable component supply across extended product lifecycles.

Supply support for STM32L031G6U6S 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, MEMS, and automotive semiconductors since 1987.

The STM32L0 series targets ultra-low-power embedded applications, emphasizing energy efficiency, integrated analog peripherals, and long-term reliability - specifically engineered for battery-operated and energy-harvesting systems where microamp-level quiescent current and memory resilience are non-negotiable.

FAQ

What is the maximum operating frequency and corresponding power consumption of STM32L031G6U6S?

The STM32L031G6U6S runs at up to 32 MHz with dynamic voltage scaling. At 32 MHz and 3.3 V, typical Run-mode current is 1.2 mA (37.5 µA/MHz). This value scales linearly with frequency and voltage - e.g., at 16 MHz/3.0 V, consumption drops to ~0.55 mA. All values are measured with code executing from Flash and verified per DS10668 Rev 6 Table 24.

Does STM32L031G6U6S support hardware encryption or secure boot?

No, the STM32L031G6U6S does not integrate hardware cryptographic accelerators (AES, SHA, PKA) or secure boot ROM. It relies on software-based encryption libraries and external secure elements for advanced security. However, its 96-bit unique ID and ECC-protected Flash/EEPROM provide foundational integrity for firmware signing and parameter storage.

Can the internal 32 kHz LSE oscillator be used for precise RTC timekeeping without an external crystal?

No - the 32 kHz RTC clock source requires an external LSE crystal (typically 32.768 kHz) for accurate timekeeping. The internal LSI (37 kHz RC) is not calibrated and drifts significantly with temperature/voltage; it is only suitable for approximate wake timing or watchdog reference, not calendar functions.

How many ADC channels are accessible in the UFQFPN28 package, and which pins support them?

The UFQFPN28 package exposes 10 ADC channels: ADC_IN0–ADC_IN9 mapped to PA0–PA7, PB0, and PB1. All channels operate down to 1.65 V supply and support single-ended or differential acquisition. Channel mapping and alternate function configurations are defined in DS10668 Rev 6 Table 15 and Section 3.11.