STMicroelectronics STM32L431CBT3TR

Overview

STM32L431CBT3TR from STMicroelectronics is an ultra-low-power Arm® Cortex®-M4 32-bit MCU with FPU, operating up to 80 MHz (100 DMIPS), featuring 128 KB Flash, 64 KB SRAM, and integrated analog peripherals including a 12-bit 5 Msps ADC, dual 12-bit DACs, and an operational amplifier with PGA. It supports 21 capacitive sensing channels and includes CAN 2.0B, SAI, and LPUART for battery-powered industrial sensor nodes and portable medical devices.

For engineers reviewing the STM32L431CBT3TR datasheet, STM32L431CBT3TR pinout, STM32L431CBT3TR application, or STM32L431CBT3TR equivalent, key selection criteria include its 8 nA shutdown current, 4 µs wakeup from Stop mode, 280 nA Standby+RTC operation, and UFBGA64 (5×5 mm) package compatibility with space-constrained PCB layouts.

Technical Context

The device implements an Adaptive Real-time Accelerator (ART Accelerator™) enabling zero-wait-state execution from Flash at 80 MHz, paired with a memory protection unit (MPU) and proprietary code readout protection. Its FlexPowerControl architecture delivers multiple low-power modes - including Shutdown (8 nA), Standby with RTC (280 nA), and Stop 2 (1.0 µA) - all supported by dual PLLs, internal clock trimming (±0.25%), and hardware batch acquisition mode (BAM) for deterministic peripheral sampling.

Analog subsystem integration includes independent supply domains for the 12-bit ADC (5 Msps, 200 µA/Msps), two 12-bit DACs with sample-and-hold, one rail-to-rail op-amp with programmable gain amplifier (PGA), and two ultra-low-power comparators - all co-located with 21-channel touch sensing controller (TSC) and temperature sensor with factory calibration.

Key Specifications

Pinout & Package

STM32L431CBT3TR uses a 64-ball UFBGA package (5×5 mm, 0.5 mm pitch) with exposed thermal pad. Pin functions are defined per STM32L431xx datasheet Section 4 (Pinouts and pin description), with dedicated power/ground balls, flexible alternate function mapping (AF0–AF15), and 5 V-tolerant I/Os on selected pins.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STM32L432KCU6, the STM32L431CBT3TR provides CAN and SAI for industrial networking and audio, while STM32L476RGY6TR trades compact UFBGA64 size for larger memory and display capability - making the CB variant optimal for cost- and space-sensitive battery-powered edge nodes requiring robust analog and communication integration.

Availability

STM32L431CBT3TR is available at Aetrix Electronics and suitable for wearable health monitors, smart utility meters, industrial wireless sensor nodes, and portable medical diagnostic tools requiring stable component supply across long-lifecycle deployments.

Supply support for STM32L431CBT3TR 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 products for industrial, automotive, and consumer markets.

The STM32L4 series targets ultra-low-power embedded applications demanding high performance-per-milliwatt, combining Cortex-M4 processing with advanced analog integration and flexible power management for battery-operated edge intelligence.

FAQ

What is the maximum operating frequency and core type of STM32L431CBT3TR?

The STM32L431CBT3TR features an Arm Cortex-M4 core with FPU, rated for up to 80 MHz operation delivering 100 DMIPS. Its Adaptive Real-time Accelerator (ART Accelerator™) ensures zero-wait-state execution from Flash memory, enabling deterministic real-time response without external cache or SRAM booting.

Does STM32L431CBT3TR support hardware encryption or secure boot?

No, the STM32L431CBT3TR does not integrate hardware cryptographic accelerators (AES, PKA, HASH) or secure boot ROM. It provides code readout protection (RDP) Level 1/2 and firewall for peripheral access control, but secure firmware updates require external secure elements or software-based solutions using its TRNG and CRC units.

What are the key low-power mode current values for STM32L431CBT3TR?

In Shutdown mode, it draws 8 nA (with 5 wakeup pins enabled); Standby mode consumes 28 nA (no RTC) or 280 nA (with RTC active); Stop 2 mode draws 1.0 µA; and typical Run mode current is 84 µA per MHz. All values measured at 3.3 V and 25 °C per DS11453 Rev 3 Section 6.3.5.

Which package and pin count does STM32L431CBT3TR use?

The STM32L431CBT3TR uses a 64-ball Ultra-Fine Pitch Ball Grid Array (UFBGA64) package measuring 5×5 mm with 0.5 mm ball pitch. This compact, thermally enhanced package supports automated assembly and meets ECOPACK2® environmental compliance standards.