32 MHz ARM Cortex-M0+ in a 3x3 mm footprint
Memory and peripheral budget for constrained designs
With 16 KB of Flash and 2 KB of RAM, this part targets applications where code fits in a few thousand instructions and data stays small — think a temperature logger, a pulse counter, or a simple PWM fan controller. The 512-byte EEPROM is useful for calibration constants or serial numbers that survive power loss without external storage. The 16 available I/O pins in the 20-UFQFPN package mean most of the peripherals are accessible, but a dense design will need to share pins carefully.
The base product number is STM32L021, and the series is STM32L0 — a mature, widely second-sourced family. ROHS3 compliance is confirmed, which simplifies EU and global regulatory acceptance.
Package and supply-rail notes
The 20-UFQFPN package measures 3x3 mm.