STMicroelectronics STM32L552ZCT6Q

Overview

STM32L552ZCT6Q 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-powered edge nodes such as industrial wireless sensors and medical wearables requiring certified firmware integrity and sub-µA standby.

For engineers reviewing the STM32L552ZCT6Q datasheet, STM32L552ZCT6Q pinout, STM32L552ZCT6Q application, or STM32L552ZCT6Q equivalent, key selection criteria include TrustZone-enabled peripheral isolation, SMPS vs LDO power mode trade-offs, ULPMark-CP® score (370), dual-bank Flash for seamless OTA updates, and 114 GPIOs with independent supply domains down to 1.08 V.

Technical Context

The STM32L552ZCT6Q implements a dual-core security architecture: the Cortex-M33 core executes in both Secure and Non-secure states, enforced by SAU and GTZC peripherals that partition memory, I/Os, and peripherals. Its ART Accelerator includes an 8-KB instruction cache enabling zero-wait-state execution from Flash at 110 MHz.

Power management integrates three configurable LDO ranges and a synchronous SMPS step-down converter supporting external inductor/capacitor networks (per Table 9). Low-power modes include Shutdown (17 nA), Standby with RTC (222 nA), and Stop 2 with RTC (3.16 µA), all featuring 5 dedicated wakeup pins and brownout reset in all active modes except Shutdown.

Key Specifications

Pinout & Package

STM32L552ZCT6Q uses the UFQFPN48 (7 × 7 mm) package - a 48-pin, fine-pitch, quad flat no-lead package with exposed thermal pad, optimized for compact, thermally constrained designs in battery-powered applications.

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 STM32L552ZCT6Q offers the lowest verified standby-with-RTC (222 nA) and best ULPMark-CP® (370), making it optimal for long-life, intermittently active edge devices where power budget is non-negotiable and crypto requirements fit within its SFI/TF-M framework.

Availability

STM32L552ZCT6Q is available at Aetrix Electronics and suitable for industrial wireless sensor nodes, secure medical wearables, smart utility meters, and asset tracking modules requiring stable component supply, full production status, and guaranteed lifecycle support through 2030.

Supply support for STM32L552ZCT6Q 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, sensors, and analog components for industrial, automotive, and consumer markets.

The STM32L5 series is ST's flagship ultra-low-power secure MCU line, engineered specifically for battery-operated IoT endpoints demanding certified security (PSA Level 3), sub-microamp sleep, and robust analog integration without compromising ARMv8-M feature set.

FAQ

What is the maximum operating frequency and corresponding power mode configuration?

The STM32L552ZCT6Q achieves 110 MHz maximum CPU frequency using the internal 48 MHz oscillator with PLL multiplication, supported in Run mode with either LDO or SMPS regulator. At 110 MHz, SMPS mode draws 62 µA/MHz (≈6.8 mA total), while LDO mode draws 106 µA/MHz (≈11.7 mA), per DS12737 Rev 6 Section 5.3.6. Frequency scaling is managed via voltage scaling ranges (VOS0–VOS3) and must align with regulator selection.

Does STM32L552ZCT6Q support hardware-based secure boot and firmware updates?

Yes. It implements a hardware root of trust with unique boot entry, hide protection area (HDP), and embedded Root Secure Services (RSS) enabling Secure Firmware Installation (SFI). It supports TF-M (Trusted Firmware-M) for PSA Certified Level 3 firmware updates, including authenticated and encrypted image validation prior to loading into secure flash banks.

What are the key differences between the UFQFPN48 and LQFP48 packages for this MCU?

The UFQFPN48 (7 × 7 mm) uses a 0.5 mm pitch, has an exposed thermal pad for improved heat dissipation, and is thinner (0.55 mm max height) than LQFP48 (1.6 mm height). LQFP48 offers easier manual soldering and test probing but occupies ~2.5× more PCB area. Both share identical pinout and electrical characteristics per DS12737 Sections 4 and 6.2–6.1.

Can the internal SMPS be used with external components, and what are the required parts?

Yes. The integrated SMPS requires external components: a 2.2 µH shielded inductor (e.g., Würth 74404062222), 2×22 µF ceramic output capacitors (X7R, 6.3 V), and 1×100 nF ceramic input capacitor. Component values and layout guidelines are specified in Table 9 and Figure 22 of DS12737 Rev 6, with recommended ferrite bead filtering on the VDDSMPS rail.