STMicroelectronics STM32L451REY6TR

Overview

STM32L451REY6TR from STMicroelectronics is an ultra-low-power Arm® Cortex®-M4 32-bit MCU with FPU, operating up to 80 MHz (100 DMIPS), featuring 512 KB Flash, 160 KB SRAM, and integrated analog peripherals including 12-bit ADC (5 Msps), dual 12-bit DACs, op-amp with PGA, and RTC with hardware calendar-designed for battery-powered IoT sensor nodes requiring long runtime and audio-capable edge processing.

For engineers reviewing the STM32L451REY6TR datasheet, STM32L451REY6TR pinout, STM32L451REY6TR application, or STM32L451REY6TR equivalent, key selection criteria include its 2.05 µA Stop 2 mode current, 4 µs wakeup latency, LPUART wake capability, SAI audio interface, and UFBGA64 (5×5 mm) package compatibility with space-constrained portable designs.

Technical Context

The device implements an Adaptive Real-time Accelerator (ART Accelerator™) enabling zero-wait-state execution from Flash at 80 MHz, paired with a memory protection unit (MPU) and interconnect matrix for deterministic peripheral arbitration. Its FlexPowerControl architecture supports seven low-power modes-including Shutdown (22 nA), Standby with RTC (375 nA), and Stop 2 (2.05 µA)-with BOR, VBAT backup, and batch acquisition mode (BAM) for energy-efficient sensing bursts.

Clock management includes dual PLLs (system/audio), four internal oscillators (HSI16, MSI, LSI, HSI48), and external support for 4–48 MHz HSE and 32.768 kHz LSE. Analog subsystem features independent supply domains, hardware oversampling (up to 16-bit), and calibrated 2.048 V/2.5 V reference buffer-enabling precision sensor signal chain integration without external components.

Key Specifications

Pinout & Package

STM32L451REY6TR is housed in a 64-ball Ultra-Fine Pitch Ball Grid Array (UFBGA64) package with 0.4 mm ball pitch and 5×5 mm body size, optimized for automated assembly and thermal performance in compact layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STM32L451REY6TR, the STM32L476RGY6TR trades SAI for USB and larger memory, while the STM32L552RET6 adds mandatory security features at slightly higher cost and design complexity - making the L451 optimal for cost-sensitive, audio-aware, ultra-low-power edge nodes without security mandates.

Availability

STM32L451REY6TR is available at Aetrix Electronics and suitable for smart wearables, industrial wireless sensors, audio-enabled access control, and portable medical diagnostics requiring stable component supply across multi-year production cycles.

Supply support for STM32L451REY6TR 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 automotive semiconductors with vertical fabrication capacity.

The STM32L4 series targets ultra-low-power embedded applications demanding extended battery life, rich analog integration, and real-time performance - specifically engineered for IoT endpoints where energy efficiency and peripheral consolidation are primary constraints.

FAQ

What is the maximum allowed VDD voltage for STM32L451REY6TR?

The absolute maximum VDD rating is 4.0 V per electrical characteristics (Section 6.2), but the recommended operating range is strictly 1.71 V to 3.6 V. Exceeding 3.6 V risks permanent damage to I/O structures and Flash memory, especially during hot-plug events or regulator overshoot - use a 3.3 V ±5% LDO with adequate transient suppression.

Does STM32L451REY6TR support hardware encryption acceleration?

No, STM32L451REY6TR does not include dedicated cryptographic accelerators (AES, SHA, PKA). It relies on software libraries (e.g., Mbed TLS) running on the Cortex-M4 core. For hardware crypto, consider STM32L552xx or STM32U5xx series - the L451 provides TRNG and CRC units only, sufficient for key generation and integrity checks but not high-throughput encryption.

Can the internal 32 kHz RC oscillator replace the LSE crystal for RTC operation?

Yes, the internal LSI (37 kHz ±5%) can drive the RTC in all low-power modes, but it lacks the stability and accuracy of the 32.768 kHz LSE crystal. LSI drift exceeds ±500 ppm over temperature, causing >2 minutes/day time error - acceptable for coarse timestamping but unsuitable for time-critical applications like synchronized sensor networks or regulatory-compliant logging.

How many GPIOs are available in the UFBGA64 package of STM32L451REY6TR?

The UFBGA64 package provides 51 user-accessible GPIOs (PA0–PA15, PB0–PB15, PC0–PC15, PD2, PD8–PD15, PE0–PE7), excluding power, reset, debug, and oscillator pins. All are 5 V-tolerant in digital mode and support up to 16 alternate functions - verified in Section 4 (Pinouts and pin description) and Table 16 of DS11910 Rev 5.