STMicroelectronics STM32L051R6T6

Overview

STM32L051R6T6 from STMicroelectronics is an ultra-low-power 32-bit Arm® Cortex®-M0+ microcontroller with 32 MHz max CPU frequency, 64 KB Flash (ECC-protected), 8 KB SRAM, and 2 KB EEPROM - deployed in battery-powered IoT sensors, smart meters, and wearable health monitors requiring sub-1 µA Stop mode current and fast 3.5 µs wakeup from RAM.

For engineers reviewing the STM32L051R6T6 datasheet, STM32L051R6T6 pinout, STM32L051R6T6 application, or STM32L051R6T6 equivalent, key selection criteria include its 0.4 µA Stop mode (16 wakeup lines), 12-bit 1.14 Msps ADC with 16-channel support down to 1.65 V, dual ultra-low-power comparators, and integrated 16 MHz HSI RC oscillator trimmed to ±1% - all in a 64-pin LQFP package.

Technical Context

The STM32L051R6T6 implements dynamic voltage scaling and multiple low-power modes (Run, Sleep, Low-power Run/Sleep, Stop, Standby) with hardware-based power gating. Its Cortex-M0+ core includes a Memory Protection Unit (MPU) and supports Thumb-2 instruction set for deterministic real-time execution.

Peripherals are interconnected via an AHB/APB matrix enabling concurrent DMA transfers to ADC, USART, SPI, I²C, and timers. Clock management integrates six oscillators (HSE, LSE, HSI16, LSI, MSI, PLL), with automatic clock source switching and calibration for RTC and system timing stability across temperature and voltage.

Key Specifications

Pinout & Package

LQFP64 (10 × 10 mm, 0.5 mm pitch) package with exposed thermal pad - optimized for industrial PCB assembly and thermal dissipation in compact enclosures.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STM32L051R6T6, the STM32L071RBT6 offers scalable memory within identical ultra-low-power architecture and footprint, while the EFM32PG12B500F1024GL125 trades EEPROM and smart-card support for higher computational headroom - making the STM32L051R6T6 optimal for cost-sensitive, EEPROM-dependent, standards-compliant metering designs.

Availability

STM32L051R6T6 is available at Aetrix Electronics and suitable for smart utility metering, wearable health monitoring, industrial wireless sensor nodes, and asset tracking beacons requiring stable component supply across multi-year production cycles.

Supply support for STM32L051R6T6 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 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 certified compliance with IEC 62368 and EN 61000-4 standards - especially in metering, healthcare, and environmental monitoring.

FAQ

What is the maximum operating temperature range for the STM32L051R6T6?

The STM32L051R6T6 is rated for operation from –40 °C to +125 °C ambient temperature. This extended range is validated per ST's production test flow and supports deployment in harsh environments such as outdoor utility meters, engine bay sensors, and industrial control cabinets without external thermal derating.

Does the STM32L051R6T6 support hardware encryption or secure boot?

No - the STM32L051R6T6 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 advanced authentication. Its 96-bit unique ID and ECC-protected memory support foundational trust anchors but require external implementation for full secure boot.

Can the internal 16 MHz RC oscillator be used as the system clock without calibration?

Yes - the HSI16 oscillator is factory-trimmed to ±1% accuracy across voltage and temperature, enabling immediate use as the system clock without runtime calibration. It supports full-speed operation (32 MHz via PLL) and is the default clock source after reset, eliminating need for external crystals in cost-sensitive designs.

How many I/O pins support 5 V tolerance on the STM32L051R6T6?

45 of the 51 general-purpose I/O pins are 5 V tolerant when configured in input, output, or alternate function modes. This is confirmed in Section 3.7 (GPIOs) and Table 54 (I/O static characteristics) of DS10184 Rev 10 - enabling direct interfacing with 5 V logic, industrial sensors, and legacy peripherals without external level shifters.