The STMicroelectronics STM8S103K3T3C is an 8-bit MCU from the STM8S series, built around the STM8 core and clocked at 16 MHz.
Memory and peripheral fit for production firmware
With 8 KB of Flash and 1 KB of RAM, firmware must stay lean — think state-machine control, Modbus slave, or a simple PID loop. The 640-byte EEPROM is handy for calibration constants or fault logs that survive power cycles. Four 10-bit ADC channels handle analog inputs like thermistors or potentiometers.
The STM8S103K3T3C comes in a 32-LQFP package (7x7 mm body) with 28 usable I/O lines. Surface-mount only — no DIP option. The LQFP footprint is standard; no exotic pad geometry. If you are replacing a 32-pin QFP MCU on an existing board, check the pinout against the STM8S reference manual — the peripheral mapping differs from the STM8S003K3T6C in a few positions.