STMicroelectronics STM32L031E4Y6TR

Overview

STM32L031E4Y6TR from STMicroelectronics is an ultra-low-power 32-bit Arm® Cortex®-M0+ microcontroller in a 28-pin UFQFPN package, featuring 16 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 V to 3.6 V across –40 °C to +125 °C and delivers 76 µA/MHz in Run mode - ideal for battery-powered sensor nodes and smart metering endpoints.

For engineers reviewing the STM32L031E4Y6TR datasheet, STM32L031E4Y6TR pinout, STM32L031E4Y6TR application, or STM32L031E4Y6TR equivalent, key selection criteria include standby current (0.23 µA), RTC-enabled Stop mode (0.6 µA with 8 KB RAM retention), 5 µs wakeup from Flash, and 31 I/Os with 5V tolerance - all critical for energy-constrained embedded control designs.

Technical Context

The STM32L031E4Y6TR 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 boosting. Its low-power architecture includes five operational modes - Run, Sleep, Low-power Run, Stop, and Standby - each with distinct power/performance tradeoffs verified down to 1.65 V supply.

Peripheral interconnect is managed via an AHB/APB matrix supporting simultaneous DMA transfers to ADC, USART, SPI, I²C, and timers. The device implements hardware ECC on both Flash and EEPROM, and embeds a 96-bit unique ID plus CRC calculation unit - enabling secure firmware updates and data integrity in field-deployed IoT edge nodes.

Key Specifications

Pinout & Package

STM32L031E4Y6TR uses a 28-pin Ultra-Fine Pitch Quad Flat No-lead (UFQFPN28) package, 4 × 4 mm, 0.5 mm pitch, with exposed thermal pad. This compact, RoHS-compliant ECOPACK®2 package supports high-density PCB layouts and efficient thermal dissipation in space-constrained industrial and portable designs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STM32L011E4Y6TR, the STM32L031E4Y6TR adds EEPROM for robust parameter storage and doubles Flash for complex sensor fusion; versus STM32L051E6Y6TR, it trades 16 KB Flash for guaranteed 125 °C operation - making it optimal for thermally demanding metering and motor control edge nodes.

Availability

STM32L031E4Y6TR is available at Aetrix Electronics and suitable for smart utility metering, wireless sensor nodes, industrial control panels, and medical wearable monitors requiring stable component supply across long product lifecycles.

Supply support for STM32L031E4Y6TR 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 devices, sensors, and analog ICs for industrial, automotive, and consumer markets.

The STM32L0 series targets ultra-low-power embedded applications, emphasizing energy efficiency, integrated security features, and long-term supply stability - specifically engineered for battery-operated IoT endpoints and energy-harvesting systems.

FAQ

What is the maximum operating frequency and corresponding supply voltage range?

The STM32L031E4Y6TR achieves its maximum 32 MHz CPU frequency only when VDD ≥ 2.4 V. At 1.65–2.4 V, the maximum allowed frequency drops to 16 MHz due to dynamic voltage scaling constraints. This relationship is defined in Table 4 of DS10668 Rev 6 and enforced by hardware to guarantee timing compliance and reliability.

Does this MCU support hardware encryption or secure boot?

No, the STM32L031E4Y6TR does not integrate hardware cryptographic accelerators (AES, SHA, PKA) or secure boot ROM. It relies on software-based security libraries and external secure elements for authentication or encrypted firmware updates. Devices with those features belong to the STM32L07x or STM32L1xx families.

Can the 1 KB EEPROM be used for storing calibration data across power cycles?

Yes - the 1 KB data EEPROM is independently erasable and writable (100 k-cycle endurance, 20-year retention at 55 °C) and retains contents during all low-power modes including Standby. It is accessed via dedicated PEC (Program/Erase Controller) registers and supports byte/word writes without affecting adjacent memory.

Is the 32.768 kHz LSE oscillator mandatory for RTC operation?

No - the RTC can operate using the internal 37 kHz LSI oscillator, but LSE is required for high-accuracy timekeeping (±20 ppm typical). When LSE is used, the RTC calibration register (RTCCALIB) allows fine-tuning to compensate for crystal aging and temperature drift, achieving <1 ppm effective accuracy over industrial temperature ranges.