Active 8-bit MCU with 16 MHz core and integrated EEPROM
The STMicroelectronics STM8S903F3M6 is an 8-bit microcontroller from the STM8S family, built around the STM8 core and clocked at 16 MHz.
16 MHz — what it buys on the bus
The 16 MHz core speed is the ceiling for instruction throughput on this 8-bit STM8 architecture. At that clock, single-cycle ALU operations execute at 16 MIPS, which is enough to handle a 10 kHz control loop with sensor read, PID calculation, and PWM update all within one cycle.
Memory budget: Flash, RAM, and EEPROM
The 8 KB Flash and 1 KB RAM suit state-machine logic. The 640 bytes of EEPROM hold calibration constants.
Supply and temperature: industrial-grade envelope
Brown-out detect and POR are integrated, so the reset circuit needs only a pull-up and a decoupling cap.
20-SOIC package: footprint and rework
Housed in a 20-SOIC (7.50 mm width) with surface-mount leads, this package is hand-solderable and inspectable under a microscope — no X-ray needed. The 1.27 mm pitch matches standard SOIC footprints, and the body width is wide enough that a hot-air rework station can remove it without damaging adjacent passives.