STMicroelectronics STM32L431RBI6

Overview

STM32L431RBI6 from STMicroelectronics is an ultra-low-power Arm® Cortex®-M4 32-bit MCU with FPU, operating up to 80 MHz (100 DMIPS), featuring 256 KB Flash, 64 KB SRAM, and integrated analog peripherals including a 12-bit 5 Msps ADC, dual 12-bit DACs, and an operational amplifier - deployed in battery-powered IoT sensor nodes requiring long runtime and real-time signal processing.

For engineers reviewing the STM32L431RBI6 datasheet, STM32L431RBI6 pinout, STM32L431RBI6 application, or STM32L431RBI6 equivalent, key selection criteria include ultra-low-power Stop 2 mode (1.0 µA), 5 V-tolerant I/Os (up to 83), hardware parity on 16 KB SRAM, Quad SPI interface for external memory, and LPUART wake-up capability in deep-sleep states.

Technical Context

The device integrates an Adaptive Real-time Accelerator (ART Accelerator™) enabling zero-wait-state execution from Flash at 80 MHz, alongside a memory protection unit (MPU) and interconnect matrix for deterministic peripheral arbitration. It supports dual PLLs - one for system clock and another for audio/ADC synchronization - and includes a dedicated low-power timer (LPTIM) functional in Stop modes.

Clock architecture combines four internal oscillators (HSI16, MSI, LSI, HSI48) with auto-trimming via LSE, plus external 4–48 MHz HSE and 32.768 kHz LSE sources. Power management implements seven low-power modes, with Shutdown mode consuming just 8 nA and RTC-enabled Standby drawing 280 nA.

Key Specifications

Pinout & Package

STM32L431RBI6 uses a 64-pin UFBGA package (5 × 5 mm, 0.5 mm pitch) with 51 user I/Os, 3 power supply pins (VDD, VSS, VDDA), 2 reset/programming pins (NRST, BOOT0), and dedicated analog supply (VREF+), VBAT, and crystal connections (HSE_IN/OUT, LSE_IN/OUT).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar ultra-low-power Cortex-M4 MCU applications.

Compared with STM32L431RBI6, STM32L432KBU6 trades package size and peripheral count for footprint reduction, while STM32L476RGY6 adds memory, USB, and display support at higher power and cost - making STM32L431RBI6 optimal for balanced ultra-low-power embedded control with moderate peripheral needs.

Availability

STM32L431RBI6 is available at Aetrix Electronics and suitable for smart utility meters, portable medical sensors, industrial predictive maintenance nodes, and asset tracking beacons requiring stable component supply across multi-year production cycles.

Supply support for STM32L431RBI6 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 automotive semiconductors since 1987.

The STM32L4 series targets energy-constrained applications demanding high performance per microwatt, with design focus on battery-powered IoT endpoints, portable healthcare devices, and industrial wireless sensors.

FAQ

What is the maximum operating temperature range for STM32L431RBI6?

The STM32L431RBI6 is qualified for industrial operation from –40 °C to +85 °C. The 'I' in the part number denotes this temperature grade; extended variants (e.g., STM32L431RCT6) support up to +105 °C, but the RBI6 variant is strictly rated to +85 °C per DS11453 Rev 3 Section 6.3.1.

Does STM32L431RBI6 support hardware encryption acceleration?

No, the STM32L431RBI6 does not integrate a cryptographic accelerator (e.g., AES, PKA, or HASH). It relies on software libraries (STM32CubeL4) for encryption; for hardware-accelerated crypto, consider STM32L4+ series parts like STM32L4R5ZIT6 which include AES-128/256 and SHA-256 engines.

Can the internal 16 MHz RC oscillator (HSI16) be used as the system clock source without calibration?

Yes, the HSI16 is factory-trimmed to ±1% accuracy and can serve as the default system clock without external components or runtime calibration. For tighter timing tolerance (e.g., USB or audio sync), the MSI oscillator auto-trimmed by LSE (±0.25%) or external crystal sources are recommended.

How many GPIO pins support external interrupt capability on STM32L431RBI6?

All 51 user GPIO pins on the UFBGA64 package support external interrupt generation via the EXTI controller. Each pin maps to one of 23 EXTI lines, with multiple pins shareable per line (e.g., PA0, PB0, PC0 all map to EXTI0), enabling flexible wake-up source configuration across all I/O banks.