STMicroelectronics STM32L031K6U3TR

Overview

STM32L031K6U3TR from STMicroelectronics is an ultra-low-power 32-bit Arm® Cortex®-M0+ microcontroller in UFQFPN32 (5 × 5 mm) package, featuring 32 KB Flash with ECC, 8 KB SRAM, 1 KB EEPROM, 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, delivering 76 µA/MHz in Run mode and 0.35 µA in Stop mode - ideal for battery-powered sensor nodes and smart metering endpoints.

For engineers reviewing the STM32L031K6U3TR datasheet, STM32L031K6U3TR pinout, STM32L031K6U3TR application, or STM32L031K6U3TR equivalent, key selection criteria include verified low-power mode current consumption (0.35 µA Stop, 0.6 µA Stop+RTC+8KB RAM), 31 5V-tolerant I/Os, integrated 16 MHz HSI oscillator (±1%), and support for SWD debug interface with serial wire debug.

Technical Context

The STM32L031K6U3TR implements a single-core Arm Cortex-M0+ running at up to 32 MHz, with dynamic voltage scaling enabling operation across three power ranges (1.65–3.6 V). Its interconnect matrix routes peripherals-including two SPIs (up to 16 Mbit/s), one USART (ISO 7816/IrDA), one LPUART, and one I²C (SMBus/PMBus)-to the CPU without arbitration overhead.

Low-power architecture integrates five distinct sleep states (Run, Sleep, Low-power Run, Low-power Sleep, Stop, Standby), each with configurable retention (e.g., 8 KB RAM + RTC in Stop mode) and wakeup sources (16 EXTI lines, 2 comparator outputs, RTC alarm). The embedded 32 kHz LSE oscillator supports ±20 ppm accuracy for RTC calibration, while the 16 MHz HSI provides factory-trimmed clocking without external components.

Key Specifications

Pinout & Package

STM32L031K6U3TR is housed in a 32-pin UFQFPN (5 × 5 mm, 0.5 mm pitch) package compliant with ECOPACK®2 environmental standards. This compact, lead-free, thermally efficient package supports reflow soldering and is optimized for space-constrained PCB layouts in portable and industrial edge devices.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STM32L031K6U3TR, STM32L011K4T6 trades memory and EEPROM for lower unit cost, while STM32L051K8U6 adds USB and doubles Flash at the expense of higher active power - making the K6U3TR optimal for cost-sensitive, battery-constrained applications needing balanced memory and ultra-low sleep current.

Availability

STM32L031K6U3TR is available at Aetrix Electronics and suitable for smart utility metering, wireless sensor nodes, industrial control panels, and portable medical devices requiring stable component supply and long-term lifecycle assurance.

Supply support for STM32L031K6U3TR 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 products for industrial, automotive, and consumer markets.

The STM32L0 series targets ultra-low-power embedded applications - specifically engineered for battery-operated devices demanding multi-year runtime, robust memory integrity, and rich analog integration in minimal footprint packages.

FAQ

What is the maximum operating frequency and core type of STM32L031K6U3TR?

The STM32L031K6U3TR features an Arm Cortex-M0+ core rated for up to 32 MHz operation, delivering 0.95 DMIPS/MHz performance. It supports dynamic voltage scaling to maintain this frequency across its full 1.65–3.6 V supply range, with factory-trimmed 16 MHz HSI oscillator providing ±1% accuracy for crystal-free startup and operation.

Does STM32L031K6U3TR support hardware-based error correction for memory?

Yes - both the 32 KB Flash and 1 KB EEPROM include built-in ECC (Error Correction Code) circuitry that detects and corrects single-bit errors in real time. This eliminates the need for software-based checksums or external memory controllers in safety-critical or high-reliability applications such as utility metering and industrial monitoring.

How many I/O pins are 5V tolerant, and which ones are excluded?

31 of the 32 GPIOs are 5V tolerant, including all PA and PB port pins and PC13–PC15. Only analog input pins (e.g., PA0–PA7 when configured as ADC_INx) lose 5V tolerance - they are limited to VDD + 0.3 V. This allows direct interfacing with 5V logic without level shifters in most digital functions, reducing BOM count and layout complexity.

What debug interface does STM32L031K6U3TR use, and what tools are compatible?

The device uses Serial Wire Debug (SWD), a 2-pin (SWDIO/SWCLK) ARM-standard interface supported by ST-LINK/V2, ST-LINK/V3, and third-party debuggers like Segger J-Link. It enables full read/write memory access, breakpoint setting, and real-time variable inspection - all without occupying UART or other communication peripherals during development.