32 MHz Cortex-M0+ with 32 KB Flash — the power-constrained sensor node choice
The STM32L031F6P6: It packs 32 KB of Flash, 8 KB of SRAM, and 1 KB of embedded EEPROM in a compact 20-TSSOP package with 15 I/O. The part is built for battery-operated and energy-harvesting applications — think wireless sensor nodes, IoT edge devices, and portable instrumentation — where every microamp matters. The internal oscillator and brown-out / POR / DMA / PWM peripherals let it run with minimal external components.
Memory sizing — 32 KB Flash, 8 KB SRAM, 1 KB EEPROM
32 KB of program Flash is enough for a lightweight BLE stack, a Modbus RTU slave, or a sensor-fusion loop — but leaves little room for OTA update staging or a full RTOS. The 8 KB SRAM handles modest data buffers; if your application needs a large frame buffer or a TCP/IP stack, you'll want to move up the STM32L0 density ladder.
20-TSSOP package — 15 I/O in a 4.4 mm wide body
The 20-TSSOP is a surface-mount package with a 4.4 mm body width and 0.65 mm pitch.
There is no end-of-life notification, no last-time-buy window looming. For dual-sourcing resilience, the STM32L0 series includes pin-compatible density variants — the same 20-TSSOP footprint scales up to 64 KB Flash — so you can adjust BOM allocation without a board respin.