STMicroelectronics STM32L031G6U6STR

Overview

STM32L031G6U6STR from STMicroelectronics is an ultra-low-power 32-bit Arm® Cortex®-M0+ microcontroller with 32 KB Flash, 8 KB SRAM, 1 KB EEPROM, 12-bit ADC (1.14 Msps), and operating voltage range of 1.65–3.6 V. It delivers 0.95 DMIPS/MHz performance at up to 32 MHz and supports -40 to +125 °C industrial temperature operation. Used in battery-powered sensor nodes requiring long-term autonomous operation with RTC and wake-up capability.

For engineers reviewing the STM32L031G6U6STR datasheet, STM32L031G6U6STR pinout, STM32L031G6U6STR application, or STM32L031G6U6STR equivalent, key selection criteria include standby current (0.23 µA), Stop mode + RTC + RAM retention (0.6 µA), 5 µs Flash wakeup time, and 31 I/Os with 5V tolerance - critical for energy-constrained embedded control and metering designs.

Technical Context

The STM32L031G6U6STR integrates a Cortex-M0+ core with dynamic voltage scaling and multiple low-power clock sources: 32 kHz LSE for RTC, 16 MHz HSI16 factory-trimmed ±1%, and multispeed MSI (65 kHz–4.2 MHz). Its power management includes five BOR thresholds, programmable voltage detector (PVD), and POR/PDR circuitry optimized for stable operation across wide supply and temperature ranges.

Peripheral interconnect uses a dedicated AHB/APB matrix supporting concurrent DMA transfers to ADC, USART, SPI, I²C, and timers. The 7-channel DMA controller enables zero-CPU-load data movement, while the ultra-low-power comparators (with window mode and wake-up capability down to 1.65 V) provide hardware-triggered event response without CPU intervention.

Key Specifications

Pinout & Package

STM32L031G6U6STR is housed in a 28-pin UFQFPN package (4 × 4 mm, 0.5 mm pitch), compliant with ECOPACK®2 environmental standards. This compact, lead-free, thermally enhanced package supports reflow soldering and is suitable for space-constrained PCB layouts in portable and industrial modules.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STM32L011K4T6, the STM32L031G6U6STR adds 1 KB EEPROM and doubles Flash capacity - enabling local data logging without external memory. Versus STM32L053R8T6, it trades package size and USB for lower BOM cost and smaller footprint, making it optimal for minimal-feature, space- and power-constrained nodes.

Availability

STM32L031G6U6STR 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 across multi-year production cycles.

Supply support for STM32L031G6U6STR 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 automotive-grade components since 1987.

The STM32L0 series targets ultra-low-power embedded applications demanding sub-µA standby current, integrated EEPROM, and robust operation from 1.65 V - optimized for battery-operated IoT endpoints and industrial monitoring systems.

FAQ

What is the maximum operating frequency and corresponding power consumption in Run mode?

The STM32L031G6U6STR operates up to 32 MHz with dynamic voltage scaling. At 32 MHz and 3.3 V, typical Run mode current is 76 µA/MHz (≈2.43 mA total), measured with code executing from Flash memory and all peripherals disabled. This value scales linearly with clock frequency under identical conditions.

Does this MCU support hardware encryption or secure boot features?

No. The STM32L031G6U6STR does not integrate hardware cryptographic accelerators (AES, SHA, PKA) or secure boot ROM. Security relies on software-implemented algorithms and external secure elements. For certified secure boot, consider STM32L4 or STM32H5 series MCUs with TrustZone or proprietary secure firmware solutions.

Can the internal 32 kHz LSE oscillator be used without an external crystal?

No. The LSE oscillator requires an external 32.768 kHz quartz crystal connected between PC14 and PC15 to function. The MCU does not include a built-in RC alternative for RTC clocking; however, the internal 37 kHz LSI RC can serve as a lower-accuracy backup RTC source if crystal startup fails.

How many independent PWM outputs can be generated simultaneously?

Up to 12 independent PWM outputs are possible: TIM2 (4 channels), TIM21 (2 channels), TIM22 (2 channels), and LPTIM (1 channel with configurable polarity). Channel availability depends on GPIO remapping and peripheral clock configuration; all timers support center-aligned and edge-aligned modes with dead-time insertion on advanced channels.