32 MHz Cortex-M0+ with 192 KB Flash — the ultra-low-power workhorse
It packs 192 KB of Flash program memory, 20 KB of SRAM, and 6 KB of embedded EEPROM — enough for a firmware stack with OTA staging and non-volatile parameter storage without an external serial EEPROM.
Memory headroom and the EEPROM advantage
The 20 KB SRAM supports a lightweight RTOS with a few active tasks and a modest data buffer. The 6 KB EEPROM is the standout — it stores calibration constants, device configuration, and event logs without needing an external I²C EEPROM, saving board space and BOM cost. The EEPROM endurance is typically 100k cycles per byte, which suits frequent parameter updates in metering or field-configurable devices.
Package and footprint: 48-LQFP
Housed in a 48-LQFP package (7x7 mm body), the STM32L071CZT7 offers 37 general-purpose I/Os. The LQFP footprint is hand-solderable and inspectable, which benefits prototyping and low-volume production. The 0.5 mm pitch requires careful PCB routing for the supply and ground pins, but the package is standard across the STM32L0 series, easing layout reuse if you migrate between density options.