STMicroelectronics STM32L431RBT6TR

Overview

STM32L431RBT6TR 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 12-bit ADC (5 Msps), dual 12-bit DACs, op-amp with PGA, and two ultra-low-power comparators - deployed in battery-powered industrial sensors and portable medical monitors.

For engineers reviewing the STM32L431RBT6TR datasheet, STM32L431RBT6TR pinout, STM32L431RBT6TR application, or STM32L431RBT6TR equivalent, key selection criteria include verified low-power mode current (28 nA Standby, 84 µA/MHz Run), LQFP64 package compatibility, ART Accelerator™-enabled zero-wait-state Flash execution, and hardware-supported capacitive touch sensing across 21 channels.

Technical Context

The device integrates an Adaptive Real-time Accelerator (ART Accelerator™) enabling zero-wait-state execution from Flash at 80 MHz, coupled with a memory protection unit (MPU) and interconnect matrix for deterministic peripheral arbitration. Its power architecture supports seven low-power modes - including Stop 2 (1.28 µA with RTC) and Shutdown (8 nA) - managed via dedicated voltage regulator and BOR circuitry.

Clock system includes dual PLLs (system/audio), auto-trimmed MSI (100 kHz–48 MHz, ±0.25%), HSE (4–48 MHz), LSE (32.768 kHz), and HSI48 for USB/SAI timing. Analog subsystem operates on independent supply rails with hardware oversampling (up to 16-bit), built-in VREFBUF, and temperature sensor calibrated per-die.

Key Specifications

Pinout & Package

LQFP64 package with 64-pin square outline, exposed thermal pad, and standard 0.5 mm lead pitch. Pin functions validated per STMicroelectronics DS11453 Rev 3 (pages 55–59).

Key Features

Applications

Equivalent & Alternatives

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

Compared with STM32L431RBT6TR, STM32L433RBT6 adds security and USB at higher cost and power, while STM32L412RBT6 trades analog capability and memory for lower price and marginally better ultra-low-power metrics - making the L431 the balanced choice for mixed-signal, battery-constrained designs requiring DACs and SAI.

Availability

STM32L431RBT6TR is available at Aetrix Electronics and suitable for industrial sensor nodes, portable medical monitors, smart utility meters, and asset tracking beacons requiring stable component supply across extended product lifecycles.

Supply support for STM32L431RBT6TR 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 analog chips for industrial, automotive, and consumer markets.

This device belongs to the STM32L4 ultra-low-power MCU product line, engineered specifically for energy-constrained applications demanding rich analog integration, real-time performance, and long operational lifetime on primary batteries or energy harvesting sources.

FAQ

What is the maximum operating temperature for STM32L431RBT6TR?

The STM32L431RBT6TR is qualified for industrial operation from –40 °C to +105 °C ambient temperature, as confirmed in DS11453 Rev 3 Section 6.3.1. This rating applies to the LQFP64 package variant and is validated under specified voltage and load conditions per ST's production test flow.

Does STM32L431RBT6TR support hardware encryption?

No - the STM32L431RBT6TR does not integrate a hardware cryptographic engine. Unlike the STM32L433 or L476 variants, it lacks AES, PKA, or HASH accelerators. Secure operations must be implemented in software or via external secure elements interfaced through I²C or SPI.

Can the internal op-amp drive a 50 Ω load directly?

No - the integrated op-amp is rated for rail-to-rail output swing into ≥5 kΩ loads per DS11453 Section 6.3.22. Driving 50 Ω requires external buffer amplification; the device's op-amp is optimized for sensor signal conditioning and PGA stages, not low-impedance line driving.

Is Quad-SPI interface available on all LQFP64 pins?

No - Quad-SPI signals (IO0–IO3, SCK, NCS) are assigned to specific pins (PB2, PA6–PA7, PA12, PB10) in the LQFP64 package, as defined in Table 15 of DS11453. These pins are fixed and cannot be remapped; other GPIOs do not support Quad-SPI alternate function.