STMicroelectronics STM32U031R8I6

Overview

STM32U031R8I6 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, op-amp with PGA, and ultra-low-power comparator - deployed in battery-powered IoT sensors and portable medical monitors.

For engineers reviewing the STM32U031R8I6 datasheet, STM32U031R8I6 pinout, STM32U031R8I6 application, or STM32U031R8I6 equivalent, key selection criteria include VBAT-mode current (130 nA with RTC), Stop 2 mode consumption (515–630 nA), 53 GPIOs (most 5 V-tolerant), ART Accelerator enabling 0-wait-state execution at 56 MHz, and PSA Level 1/SESIP Level 3 security certification readiness.

Technical Context

The STM32U031R8I6 implements a tightly coupled Arm Cortex-M0+ core with MPU, paired with ST's ART Accelerator for zero-wait-state flash execution at 56 MHz. Its power architecture integrates dual regulators (main and low-power) and supports five low-power modes - Shutdown (16 nA), Standby (30–160 nA), Stop 2 (515–630 nA), Low-power Run (2 MHz max), and Sleep - all managed via PWRCTRL and SYSCFG peripherals.

Analog subsystems operate on independent supplies (VDDA = 1.62–3.6 V), enabling simultaneous high-precision sensing (12-bit ADC + 16× hardware oversampling) and low-noise signal conditioning (op-amp with gain up to 16, rail-to-rail comparator). Security includes HDP, RDP Level 2, TRNG (NIST SP 800-90B candidate), and 5 passive anti-tamper pins.

Key Specifications

Pinout & Package

LQFP64 (10 × 10 mm, ECOPACK2-compliant) package with 64 leads; pinout validated per DS14581 Rev 2 (pages 37–47) and RM0503 reference manual.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar ultra-low-power Arm Cortex-M0+ microcontroller applications.

Compared with STM32L071RBT6, the STM32U031R8I6 delivers superior analog integration and lower active-mode current (52 µA/MHz vs. 210 µA/MHz), while EFM32PG12B500F1024GL125 trades ultra-low-power efficiency for computational headroom - making the U031 optimal for cost-constrained, battery-limited sensing endpoints.

Availability

STM32U031R8I6 is available at Aetrix Electronics and suitable for wireless sensor nodes, portable medical monitors, smart utility meters, and industrial PLC I/O modules requiring stable component supply across multi-year production cycles.

Supply support for STM32U031R8I6 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 management ICs, MEMS, and automotive semiconductors since 1987.

The STM32U0 series targets ultra-low-power embedded applications demanding <1 µA standby current, PSA-certifiable security, and integrated analog - specifically engineered for battery-operated IoT endpoints and medical wearables where energy efficiency and functional safety coexist.

FAQ

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

The STM32U031R8I6 operates at up to 56 MHz in Run mode with the LDO regulator enabled, consuming 52 µA/MHz - measured at 3.3 V and 25 °C per DS14581 Rev 2. This translates to approximately 2.91 mA at full speed, scalable down via dynamic voltage/frequency scaling and ART Accelerator optimization.

Does the device support hardware-accelerated cryptographic operations?

No, the STM32U031R8I6 does not include dedicated cryptographic accelerators (AES, SHA, PKA). It relies on software libraries for encryption, but features a TRNG compliant with NIST SP 800-90B for high-entropy key generation and RDP Level 2 with password-based regression for firmware protection.

How many capacitive sensing channels are supported, and what topologies are enabled?

The STM32U031R8I6 supports up to 18 capacitive sensing channels using its built-in CSD peripheral, enabling touchkey, linear slider, and rotary wheel topologies - all configurable via STM32CubeMX and validated per AN4998 application note for noise-immune operation in industrial environments.

What are the VDDA supply requirements for simultaneous use of ADC, DAC, OPAMP, and comparator?

VDDA must be set to 1.80 V when using the DAC or op-amp, and 1.62 V minimum when using only the ADC or comparator. The datasheet specifies separate voltage thresholds: 1.62 V ≤ VDDA ≤ 3.6 V for ADC/COMP, and 1.80 V ≤ VDDA ≤ 3.6 V for DAC/OPAMP - requiring careful power sequencing if all analog blocks are active concurrently.