16 MHz 8-bit MCU in a 3x3 mm footprint
The 20-pin UFQFPN package measures 3x3 mm, which makes it a fit for compact sensor modules, handheld tools, and industrial I/O nodes where board area is the tightest constraint.
Memory budget: 8 KB Flash, 1 KB RAM, 640 B EEPROM
8 KB of Flash is the hard ceiling for firmware size — confirm your compiled binary fits before committing the BOM. The 1 KB SRAM limits buffering and call-stack depth; designs with large lookup tables or multiple interrupt contexts will need to budget carefully. The 640 bytes of data EEPROM is a genuine advantage: it stores calibration constants, configuration parameters, and fault logs without an external serial EEPROM, saving board space and cost.
The 5-channel 10-bit ADC handles analog sensing tasks like thermistor or potentiometer inputs.
ST's product status for this part is Active — no last-time-buy notice, no EOL pressure for current designs.