STMicroelectronics STM32U031C8U6

Overview

STM32U031C8U6 from STMicroelectronics is an ultra-low-power 32-bit Arm® Cortex®-M0+ microcontroller operating up to 56 MHz, featuring 64-Kbyte flash memory, 12-Kbyte SRAM with hardware parity, and integrated analog peripherals including a 12-bit ADC (0.4 µs conversion), 12-bit DAC, operational amplifier with PGA, and ultra-low-power comparator - deployed in battery-powered IoT sensors and portable medical monitors.

For engineers reviewing the STM32U031C8U6 datasheet, STM32U031C8U6 pinout, STM32U031C8U6 application, or STM32U031C8U6 equivalent, key selection criteria include verified shutdown current (16 nA), RTC retention in VBAT mode (130 nA), Stop 2 mode consumption (515–630 nA), 53 fast I/Os (most 5 V-tolerant), and ECOPACK2-compliant UFQFPN32 (5 × 5 mm) packaging.

Technical Context

The STM32U031C8U6 implements an ART Accelerator with 1-Kbyte instruction cache enabling 0-wait-state execution from flash at 56 MHz, and integrates dual voltage regulators (main and low-power) to support dynamic power mode transitions across Run, Stop 2, Standby, and Shutdown states. Its Cortex-M0+ core includes an MPU for RTOS-based memory isolation and deterministic interrupt handling.

Analog subsystem operation is decoupled via independent VDDA (1.62–3.6 V) and VBAT (1.55–3.6 V) supplies, enabling simultaneous RTC backup register retention, 18-channel capacitive sensing, and rail-to-rail analog comparator operation while maintaining 16 nA shutdown current - validated per DS14581 Rev 2.

Key Specifications

Pinout & Package

STM32U031C8U6 is housed in a 32-pin Ultra-Fine Pitch Quad Flat No-lead (UFQFPN) package measuring 5 × 5 mm with 0.5 mm pitch, compliant with ECOPACK2 environmental standards and optimized for space-constrained PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STM32L031K6T6, the STM32U031C8U6 provides integrated analog peripherals and 3× lower Stop 2 current; versus EFM32PG12B500F1024GL125, it delivers 20× better sub-µA efficiency at the cost of reduced compute bandwidth - making it optimal for energy-constrained edge sensing.

Availability

STM32U031C8U6 is available at Aetrix Electronics and suitable for wearable health monitors, smart utility meters, industrial wireless sensor nodes, and portable diagnostic tools requiring stable component supply across long-lifecycle deployments.

Supply support for STM32U031C8U6 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, delivering silicon solutions for automotive, industrial, and consumer markets with emphasis on energy efficiency and system integration.

The STM32U0 series targets ultra-low-power embedded applications demanding <1 µA standby operation, integrated analog, and PSA-certified security - designed specifically for battery-operated IoT endpoints and medical wearables.

FAQ

What is the minimum supply voltage for STM32U031C8U6 operation?

The STM32U031C8U6 operates from 1.71 V to 3.6 V on VDD. Below 1.71 V, brownout reset (BOR) activates to prevent unreliable flash access or SRAM corruption. The internal LDO regulator maintains stable VCORE down to this threshold, and VDDA must be ≥1.62 V for ADC operation or ≥1.80 V for DAC/OPAMP functionality.

Does STM32U031C8U6 support hardware encryption acceleration?

No, the STM32U031C8U6 does not include dedicated AES or PKA hardware accelerators. It relies on software libraries (e.g., STM32CubeU0 Crypto API) for cryptographic operations. However, its True Random Number Generator (TRNG) is NIST SP 800-90B candidate and supports secure boot key derivation and nonce generation for TLS handshakes.

Can the 12-bit DAC output drive a speaker directly?

No, the integrated 12-bit DAC has rail-to-rail output but lacks current drive capability (typical load ≤5 kΩ). It is designed for precision reference generation or feeding external op-amp stages - not direct audio transducer drive. For speaker output, an external Class-D or AB amplifier stage is required.

How many GPIOs are available in the UFQFPN32 package of STM32U031C8U6?

The STM32U031C8U6 in UFQFPN32 provides 27 GPIOs, including 4 dedicated wakeup pins. This matches the "C8" variant specification in Table 1 of DS14581 Rev 2, where STM32U031C8 is explicitly listed with 27 GPIOs and 4 wakeup inputs - confirmed across pin assignment diagrams and package mapping tables.