STMicroelectronics STM32L431CBY7TR

Overview

STM32L431CBY7TR 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. It supports 200 nA VBAT mode and 8 nA shutdown mode, targeting battery-powered IoT sensors and portable medical devices.

For engineers reviewing the STM32L431CBY7TR datasheet, STM32L431CBY7TR pinout, STM32L431CBY7TR application, or STM32L431CBY7TR equivalent, key selection criteria include low-power mode timing (4 µs wakeup from Stop), FlexPowerControl architecture, ART Accelerator™ for zero-wait-state Flash execution, and hardware parity on 16 KB SRAM.

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 interconnect matrix for deterministic peripheral arbitration. Its power architecture includes three voltage scaling modes (VOS0–VOS2) and five low-power states (Shutdown, Standby, Stop 0/1/2), each with distinct clock gating and memory retention policies.

Clock management integrates dual PLLs (system and audio), four internal oscillators (HSI16, MSI, LSI, HSI48), and external crystal support (4–48 MHz HSE, 32.768 kHz LSE). Analog subsystems operate from independent supplies, supporting simultaneous ADC conversion (5 Msps) and DAC output with sample-and-hold.

Key Specifications

Pinout & Package

STM32L431CBY7TR uses a 64-ball UFBGA package (5×5 mm, 0.5 mm pitch) with 53 user-accessible I/Os. Ball pitch and footprint comply with JEDEC MO-277AA, supporting automated assembly and thermal reliability in industrial temperature range (–40 °C to +105 °C).

Key Features

Applications

Equivalent & Alternatives

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

Compared with STM32L431CBY7TR, the STM32L431RCT6 offers greater I/O and memory scalability but sacrifices compactness, while the STM32L412KBU6 reduces analog capability and interface options to meet aggressive size/cost targets - all three share identical low-power architecture and ART Accelerator™ performance.

Availability

STM32L431CBY7TR 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 extended product lifecycles.

Supply support for STM32L431CBY7TR 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 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, with design focus on energy harvesting, battery longevity, and secure firmware execution in constrained environments.

FAQ

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

The STM32L431CBY7TR operates at up to 80 MHz with ART Accelerator™ enabled. At 80 MHz and 3.3 V supply, typical Run mode current is 84 µA/MHz (6.72 mA total), measured with code executing from Flash and prefetch enabled. This value scales linearly with frequency and varies ±10% across voltage and temperature ranges per DS11453 Rev 3 Table 26.

Does STM32L431CBY7TR support hardware encryption acceleration?

No, the STM32L431CBY7TR does not integrate dedicated cryptographic accelerators (e.g., AES, SHA, PKA). It relies on software libraries (STM32CubeL4) for encryption, supported by its true RNG and 96-bit unique ID. For hardware-accelerated crypto, consider the STM32L4+ series (e.g., STM32L4R5) which includes AES-256 and HASH processors.

How many I/O pins support 5 V tolerance, and are they configurable per pin?

53 of the 64 UFBGA64 balls are general-purpose I/Os, and "most" are 5 V-tolerant as specified in DS11453 Section 3.12 and Table 15. Tolerance is inherent to the I/O structure and cannot be disabled or configured - all listed 5 V-tolerant pins (e.g., PA0–PA15, PB0–PB15, PC0–PC15, PD2, PF0–PF1) maintain this rating regardless of mode or alternate function.

What debug interfaces are supported, and is SWD sufficient for full development?

The device supports Serial Wire Debug (SWD) and JTAG via the SWJ-DP interface. SWD is fully sufficient for programming, real-time debugging, and trace (via ETM) - it uses only two pins (SWCLK, SWDIO) and delivers identical functionality to JTAG for all standard development tasks, making it ideal for space-constrained PCB layouts.