STMicroelectronics STM32L051R8T6

Overview

STM32L051R8T6 from STMicroelectronics is an ultra-low-power 32-bit Arm® Cortex®-M0+ microcontroller with 64 KB Flash, 8 KB SRAM, 2 KB ECC-protected 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 IoT sensor nodes requiring long-term autonomous operation with RTC, analog sensing, and secure firmware updates.

For engineers reviewing the STM32L051R8T6 datasheet, STM32L051R8T6 pinout, STM32L051R8T6 application, or STM32L051R8T6 equivalent, key selection criteria include standby current (0.27 µA), wakeup time from Flash (5 µs), 45 I/Os with 5V tolerance, integrated EEPROM endurance (100k cycles), and SW-DP debug support for low-power firmware validation.

Technical Context

The STM32L051R8T6 integrates an Arm Cortex-M0+ core with Memory Protection Unit (MPU), supporting dynamic voltage scaling across three power ranges to optimize active and sleep-mode efficiency. Its clock system combines multiple internal RC oscillators (HSI16, LSI, MSI) and external crystal options (1–25 MHz HSE, 32 kHz LSE), enabling precise RTC calibration and flexible low-power timing.

Ultra-low-power operation is enforced via five distinct low-power modes-Run, Sleep, Low-power Run, Low-power Sleep, Stop, and Standby-with configurable retention (e.g., 8 KB RAM + RTC in Stop mode at 0.8 µA). Analog subsystem includes two comparators with window mode and wake-up capability down to 1.65 V, plus a calibrated temperature sensor referenced to VREFINT.

Key Specifications

Pinout & Package

LQFP64 (10 × 10 mm, 0.5 mm pitch) package with exposed thermal pad; RoHS-compliant ECOPACK2 construction. Pin count and layout optimized for high I/O density while maintaining routing simplicity in space-constrained industrial PCBs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STM32L071R8T6, the STM32L051R8T6 trades memory capacity for lower unit cost and smaller die size, while retaining identical ultra-low-power behavior and peripheral set; versus STM32L011K4T6, it adds 4× Flash, 4× RAM, and 26 additional I/Os - making it optimal for mid-tier industrial edge nodes balancing feature richness and power efficiency.

Availability

STM32L051R8T6 is available at Aetrix Electronics and suitable for smart metering, wireless sensor networks, predictive maintenance systems, and secure access control devices requiring stable component supply across extended product lifecycles.

Supply support for STM32L051R8T6 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 demanding sub-µA standby current, integrated EEPROM, and robust analog peripherals - specifically engineered for battery-operated IoT endpoints and industrial sensors where energy autonomy is critical.

FAQ

What is the maximum operating frequency and corresponding power supply requirement?

The STM32L051R8T6 achieves up to 32 MHz CPU frequency only when operating in Voltage Scaling Range 1 (2.4–3.6 V). At lower supply voltages (1.8–2.4 V, Range 2), max frequency drops to 16 MHz; below 1.8 V (Range 3), it is limited to 2 MHz. This dynamic scaling ensures optimal power/performance trade-off across battery discharge profiles.

Does the device support hardware-accelerated cryptography?

No, the STM32L051R8T6 does not include dedicated cryptographic accelerators (e.g., AES, SHA, PKA). It relies on software libraries for encryption tasks. For hardware crypto, consider STM32L4/L5 series or STM32WB dual-core devices with built-in AES-128 engines and secure key storage.

How many I/O pins support 5V tolerance, and under what conditions?

Exactly 45 I/O pins (PA0–PA15, PB0–PB15, PC0–PC13, PD2) are 5V tolerant when VDD is ≥ 2.0 V. Tolerance is lost if VDD falls below 2.0 V or if the pin is configured in analog mode. This enables direct interfacing with 5V sensors and logic without external level-shifting components.

What is the guaranteed data retention period for the on-chip EEPROM?

The 2 KB on-chip EEPROM guarantees 40 years of data retention at 25 °C and 100,000 write/erase cycles per sector. Retention degrades predictably with temperature - at 85 °C, retention is specified for 20 years. ECC ensures bit errors are corrected transparently during read operations.