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    Parts    STM32 Family    STM32L431    STM32L431KBU3
STM32L431KBU3

STM32L431KBU3

STMicroelectronics
ARM® Cortex®-M4 STM32L4 Microcontroller IC 32-Bit 80MHz 128KB (128K x 8) FLASH 32-UFQFPN (5x5)
Active2,383 in stock
Datasheet Digi-Key Compare Prices

Overview

The STM32L431KBU3 is an ultra-low-power microcontroller based on the high-performance ARM Cortex-M4 32-bit RISC core operating at up to 80 MHz. It balances processing power with extreme energy efficiency, featuring a Floating Point Unit (FPU), DSP instructions, and an ART Accelerator for zero-wait-state execution from Flash. The device includes 256KB of Flash and 64KB of RAM in a compact 32-pin UFQFPN package.

Why Choose This Part

This MCU offers a high performance-to-power ratio by providing 100 DMIPS at 80 MHz while maintaining very low current consumption across eight different power management modes. Its rich set of analog peripherals, including 10 ADC channels and 2 DACs, reduces the need for external components in precision signal chains.

Applications

Battery-Powered IoT Sensors
Utilizes multiple low-power modes including a 28uA standby and 7.82uA shutdown mode to extend the life of coin-cell or LiPo powered remote nodes.
Industrial Field Instrumentation
Integrates high-resolution 12-bit ADCs and DACs with CANbus and QSPI interfaces for robust sensor data acquisition and industrial networking.
Wearable Health Devices
The 5x5mm package footprint combined with low-power run modes (205uA at 2MHz) makes it suitable for space-constrained biometric monitoring.
Smart Metering
Features dedicated peripherals like the hardware oversampling unit and FlexPowerControl to manage power consumption in utility monitoring hardware.

Key Specifications

Speed 80MHz
RAM Size 64K x 8
Core Size 32-Bit
Peripherals Brown-out Detect/Reset, DMA, PWM, WDT
Connectivity CANbus, I2C, IrDA, LINbus, QSPI, SAI, SPI, SWPMI, UART/USART
Mounting Type Surface Mount
Number of I/O 26
Core Processor ARM Cortex-M4
Package / Case 32-UFQFN Exposed Pad
Data Converters A/D 10x12b; D/A 2x12b
Oscillator Type Internal
Program Memory Size 128KB (128K x 8)
Program Memory Type FLASH
Operating Temperature -40degC ~ 125degC (TA)
Supplier Device Package 32-UFQFPN (5x5)
Voltage - Supply (Vcc/Vdd) 1.71V ~ 3.6V

Getting Started

Developers can use the STM32CubeL4 software package and STM32CubeIDE for rapid firmware development. For hardware evaluation, the NUCLEO-L432KC board is a compatible reference platform using a similar 32-pin L4 series MCU. Professional debugging is supported via SWD and JTAG through ST-LINK/V2 or V3 probes.

Dev Boards

Development boards and breakout modules featuring the STM32L431KBU3 or compatible chips — ready to use for prototyping.

NUCLEO-L432KC STMicroelectronics
Development Boards & Kits - ARM STM32 Nucleo-32 dev board STM32L432KC, supports Arduino nano conn
Digi-Key Mouser 2,384 in stock
NUCLEO-L476RG STMicroelectronics
STM32L476 Nucleo-64 STM32L4 ARM® Cortex®-M4 MCU 32-Bit Embedded Evaluation Board
Digi-Key Mouser 5,230 in stock
NUCLEO-L452RE STMicroelectronics
STM32L452 Nucleo-64 STM32L4 ARM® Cortex®-M4 MCU 32-Bit Embedded Evaluation Board
Digi-Key Mouser 546 in stock
NUCLEO-L452RE-P STMicroelectronics
STM32L452 Nucleo-64 STM32L4 ARM® Cortex®-M4 MCU 32-Bit Embedded Evaluation Board
Digi-Key Mouser 126 in stock
SensorTile (STEVAL-STLCS01V1) STMicroelectronics
BlueNRG-MS, LPS22HB, LSM6DSM, LSM303AGR, MP34DT04, STM32L4 SensorTile Accelerometer, Gyroscope, Magnetometer, Microphone
Digi-Key Mouser 35 in stock
Part of STM32 family » STM32L431

STM32L431 Family

Comparing specs that differ across variants. The current part is highlighted.

Part Number Connectivity I/O Pins Package ADC/DAC Flash Temp Range Stock
STM32L431KBU3 (this part) CANbus, I2C, IrDA,.. 26 UFQFN-32 A/D 10x12b; D/A 2x.. 128KB -40degC ~ 125degC .. 2,383
STM32L431RCY6TR Tape & Reel CANbus, I2C, IrDA,.. 52 UFBGA-64 A/D 16x12b; D/A 2x.. 256KB -40degC ~ 85degC (.. 7,719
STM32L431CCU6 CANbus, I2C, IrDA,.. 39 UFQFN-48 A/D 10x12b; D/A 2x.. 256KB -40degC ~ 85degC (.. 2,230
STM32L431CCT6TR Tape & Reel CANbus, I2C, IrDA,.. 39 LQFP-48 A/D 10x12b; D/A 2x.. 256KB -40degC ~ 85degC (.. 8,289
STM32L431CBT6 CANbus, I2C, IrDA,.. 39 LQFP-48 A/D 10x12b; D/A 2x.. 128KB -40degC ~ 85degC (.. 6,847
STM32L431CCU6TR Tape & Reel CANbus, I2C, IrDA,.. 39 UFQFN-48 A/D 10x12b; D/A 2x.. 256KB -40degC ~ 85degC (.. 4,988
STM32L431CCY6TR Tape & Reel CANbus, I2C, IrDA,.. 39 UFBGA-49 A/D 10x12b; D/A 2x.. 256KB -40degC ~ 85degC (.. 3,340
STM32L431KCU6 CANbus, I2C, IrDA,.. 26 UFQFN-32 A/D 10x12b; D/A 2x.. 256KB -40degC ~ 85degC (.. 5,830
STM32L431CCT6 CANbus, I2C, IrDA,.. 39 LQFP-48 A/D 10x12b; D/A 2x.. 256KB -40degC ~ 85degC (.. 2,669
STM32L431CBU6 CANbus, I2C, IrDA,.. 39 UFQFN-48 A/D 10x12b; D/A 2x.. 128KB -40degC ~ 85degC (.. 9,376
STM32L431VCT6 CANbus, I2C, IrDA,.. 83 LQFP-100 A/D 16x12b; D/A 2x.. 256KB -40degC ~ 85degC (.. 10
STM32L431RBT6 CANbus, I2C, IrDA,.. 52 LQFP-64 A/D 16x12b; D/A 2x.. 128KB -40degC ~ 85degC (.. 17
STM32L431KBU6 CANbus, I2C, IrDA,.. 26 UFQFN-32 A/D 10x12b; D/A 2x.. 128KB -40degC ~ 85degC (.. 1,333

Also Consider

STM32L432KCU6 STMicroelectronics - Offers an integrated USB 2.0 crystal-less device controller for applications requiring PC connectivity.
ATSAML21G18B-MUT MCHPMicrochip Technology - An alternative ARM Cortex-M0+ based ultra-low power MCU with similar pin counts and competitive power consumption profiles.
STM32L431CBT6 STMicroelectronics - Provides the same internal peripheral set and memory but in a larger 48-pin LQFP package for more accessible I/O routing.