STM32L031K4U6TR — what it is and where it fits
The STMicroelectronics STM32L031K4U6TR is a 32-bit ARM Cortex-M0+ microcontroller from the STM32L0 ultra-low-power series. It runs at 32 MHz with 16 KB of Flash program memory, 8 KB of RAM, and 1 KB of embedded EEPROM. The part integrates a 10-channel 12-bit ADC, internal oscillator, and standard serial interfaces (I²C, SPI, UART/USART, IrDA, LIN). It is housed in a 32-lead UFQFPN package with exposed pad (5x5 mm) and rated for -40°C to 85°C ambient. Typical applications include battery-operated sensors, portable instrumentation, and low-power control nodes where energy efficiency and a small footprint matter.
32 MHz core — what it means for the BOM
The 32 MHz Cortex-M0+ core is the entry-level speed tier for the STM32L0 family. It handles periodic sensor reads, simple control loops, and serial communication.
Memory budget — 16 KB Flash, 8 KB RAM, 1 KB EEPROM
16 KB of Flash is tight for a full bootloader plus application code with a communication stack. Plan for a lean firmware build or use the 1 KB EEPROM for calibration constants and configuration parameters, freeing Flash for code. The 8 KB RAM supports moderate buffering — enough for a few UART packets or a small data log, but not for a large display frame buffer or extensive DSP workspace.
Lifecycle and sourcing reality
The STM32L031K4U6TR carries an EOL lifecycle stage. That means the manufacturer has announced end-of-life — a last-time-buy window is active or closing. If this part is on your BOM, now is the time to secure a final quantity or qualify a pin-compatible alternative within the STM32L0 series (same package, similar peripheral set). We source this part to order against an RFQ through independent distribution; availability and current pricing are confirmed at quote time.