STMicroelectronics STM32L552RET6Q

Overview

STM32L552RET6Q 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 dual-bank Flash with read-while-write, 256 KB SRAM (64 KB with hardware parity), and operates from 1.71–3.6 V across –40 °C to 125 °C. Used in secure, battery-powered industrial sensors requiring real-time processing, cryptographic operations, and sub-μA standby.

For engineers reviewing the STM32L552RET6Q datasheet, STM32L552RET6Q pinout, STM32L552RET6Q application, or STM32L552RET6Q equivalent, key selection criteria include TrustZone-enabled secure boot, 17 nA shutdown current, dual-bank Flash for seamless firmware updates, and integrated SMPS for >60 μA/MHz efficiency at 3 V.

Technical Context

The device implements Arm TrustZone® at the core and peripheral level, enabling hardware-isolated secure and non-secure execution environments with configurable memory attribution via SAU. Its FlexPowerControl architecture supports seven low-power modes-including 17 nA Shutdown and 222 nA Standby with RTC-managed by a dedicated power control block with BOR and voltage scaling.

Core subsystems include ART Accelerator with 8 KB instruction cache for zero-wait-state Flash execution, three independent PLLs (system/USB/audio), and dual 12-bit ADCs (5 Msps, hardware oversampling to 16-bit). Security features include NIST SP800-90B-compliant TRNG, HASH accelerator, active tamper detection, and SFI via embedded RSS.

Key Specifications

Pinout & Package

LQFP48 package (7 × 7 mm, 0.5 mm pitch), RoHS-compliant, with 46 user I/Os (most 5 V-tolerant) and dedicated VDDA/VSSA, VREF+, VREF–, VBAT, and multiple power/ground pins for noise-sensitive analog operation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STM32L552RET6Q, the STM32U575 offers greater compute headroom but sacrifices FDCAN/UCPD connectivity, while the LPC55S69 provides superior discrete security co-processing yet cannot match the 17 nA shutdown or SMPS efficiency-making STM32L552RET6Q optimal for constrained, long-life, feature-integrated edge nodes.

Availability

STM32L552RET6Q is available at Aetrix Electronics and suitable for industrial wireless sensor nodes, secure medical wearables, smart utility meters, and IIoT edge gateway controllers requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.

Supply support for STM32L552RET6Q 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, designing and manufacturing microcontrollers, power ICs, sensors, and analog products for industrial, automotive, and consumer markets.

The STM32L5 series is engineered for ultra-low-power, high-security embedded applications-combining Arm TrustZone, SMPS integration, and certified cryptographic acceleration to meet PSA Level 2 and SESIP requirements.

FAQ

What is the maximum operating frequency and corresponding power efficiency of STM32L552RET6Q?

The STM32L552RET6Q operates at up to 110 MHz with 165 DMIPS performance. In SMPS step-down converter mode, it achieves 62 μA/MHz at 3 V, verified per DS12737 Rev 6 Table 33. This efficiency enables sustained high-speed computation while maintaining multi-year battery life in portable devices.

Does STM32L552RET6Q support hardware-based secure boot and firmware updates?

Yes. It implements a hardware root of trust via unique boot entry, hide protection area (HDP), and secure firmware installation (SFI) using embedded root secure services (RSS). Firmware updates are secured through TF-M integration, with RDP levels preventing unauthorized Flash readout-validated in TrustZone-enabled boot flow diagrams (Section 3.6–3.8).

Which low-power modes retain RTC functionality and how quickly can the device wake from them?

Standby mode with RTC (222 nA) and Stop 2 mode with RTC (3.16 μA) both retain full RTC operation including calendar, alarms, and calibration. Wakeup from Stop mode takes 5 µs-measured under VDD = 3.3 V, ambient temperature 25 °C, per DS12737 Rev 6 Section 5.3.7-and is deterministic due to ART Accelerator retention.

What analog peripherals are available and what are their key precision specifications?

The device integrates two 12-bit ADCs (5 Msps, hardware oversampling to 16-bit), two 12-bit DACs with sample-and-hold, two op-amps with PGA, two ultra-low-power comparators, and a DFSDM interface. ADC accuracy is ±1 LSB INL/DNL over full temperature range (–40 °C to 125 °C), with 200 µA/Msps power consumption-specified in DS12737 Rev 6 Sections 3.21 and 5.3.19.