STMicroelectronics STM32L552MEY6QTR

Overview

STM32L552MEY6QTR from STMicroelectronics is an ultra-low-power Arm® Cortex®-M33 32-bit microcontroller with TrustZone® security, FPU, and SMPS support. It delivers 165 DMIPS at up to 110 MHz, integrates 512 KB Flash (dual-bank read-while-write), 256 KB SRAM (64 KB with hardware parity), and operates from 1.71 V to 3.6 V across –40 °C to 125 °C. It targets secure, battery-constrained IoT edge nodes requiring cryptographic acceleration, real-time sensing, and USB Type-C™ power delivery control.

For engineers reviewing the STM32L552MEY6QTR datasheet, STM32L552MEY6QTR pinout, STM32L552MEY6QTR application, or STM32L552MEY6QTR equivalent, key selection considerations include TrustZone-enabled secure boot, sub-μA low-power modes (17 nA Shutdown, 222 nA Standby with RTC), integrated SMPS efficiency (62 μA/MHz @ 3 V), dual 12-bit ADCs (5 Msps), and UCPD peripheral for USB-C PD negotiation.

Technical Context

The STM32L552MEY6QTR implements a dual-bank Flash architecture enabling seamless firmware updates without interruption, paired with an 8-KB ART Accelerator instruction cache for zero-wait-state execution at 110 MHz. Its TrustZone® partitioning enforces hardware-isolated secure and non-secure worlds, with GTZC managing memory, peripherals, and I/O securability.

Power management combines an embedded LDO and configurable SMPS step-down converter, supporting dynamic voltage scaling and external SMPS integration. Clocking includes four PLLs (system, USB, audio, ADC), internal auto-trimmed oscillators (±0.25% accuracy), and crystal-less USB FS operation - all coordinated via the RCC and CRS blocks for robust timing in resource-constrained environments.

Key Specifications

Pinout & Package

STM32L552MEY6QTR is housed in a 48-pin UFQFPN package (7 × 7 mm, 0.5 mm pitch), optimized for compact, thermally efficient PCB layouts in space-constrained IoT endpoints.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STM32U575ZIT6Q and RA4M3AFGB, the STM32L552MEY6QTR uniquely balances ultra-low-power operation (17 nA Shutdown), integrated USB-C PD control (UCPD), and NIST-certified TRNG - making it optimal for compact, battery-operated secure endpoints where power, protocol specificity, and entropy assurance are jointly critical.

Availability

STM32L552MEY6QTR is available at Aetrix Electronics and suitable for smart utility meters, wearable health monitors, industrial wireless sensor nodes, and secure access control terminals requiring stable component supply and long-term lifecycle support.

Supply support for STM32L552MEY6QTR 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 designing and manufacturing microcontrollers, analog ICs, power management, and MEMS sensors for industrial, automotive, and consumer markets.

The STM32L5 series is engineered for ultra-low-power, high-security embedded applications - combining Arm TrustZone, SMPS efficiency, and comprehensive analog integration to enable next-generation IoT endpoints with certified firmware integrity and decade-long battery life.

FAQ

What is the maximum operating frequency and corresponding power consumption in Run mode?

The STM32L552MEY6QTR achieves 110 MHz maximum CPU frequency. In Run mode with SMPS enabled at 3 V, it consumes 62 μA per MHz - resulting in approximately 6.82 mA total at full speed. With LDO, consumption rises to 106 μA/MHz (11.66 mA). These values are measured with ART Accelerator and ICACHE active, executing from Flash.

Does STM32L552MEY6QTR support secure boot and firmware updates out of the box?

Yes. It features hardware-enforced secure boot via TrustZone® and Root of Trust (unique boot entry + HDP), plus Secure Firmware Installation (SFI) using embedded Root Secure Services (RSS). Combined with TF-M support, it enables authenticated, encrypted, and rollback-protected firmware updates without external secure elements.

What package and pin count does STM32L552MEY6QTR use, and is it RoHS-compliant?

STM32L552MEY6QTR uses the UFQFPN48 package (7 × 7 mm, 0.5 mm pitch) with 48 pins. It is fully RoHS-compliant and halogen-free, meeting EU Directive 2011/65/EU and JEDEC J-STD-020 moisture sensitivity level MSL3 - suitable for lead-free reflow assembly.

Can the internal SMPS replace an external DC/DC converter in battery-powered designs?

Yes. The embedded SMPS step-down converter supports input voltages from 1.71 V to 3.6 V and delivers regulated core voltage with 62 μA/MHz efficiency at 3 V - eliminating the need for external DC/DC in most coin-cell or single-Li-ion applications. External SMPS support is also provided for higher-current or custom topologies.