This is an application note about the EMC features of STM8 microcontrollers.
This document serves as a guide for application designers to achieve optimum electromagnetic compatibility (EMC) performance with STM8 microcontrollers. It covers the intrinsic noise sensitivity of high-density CMOS technology and outlines necessary hardening techniques in hardware, PCB layout, firmware, and system design.
The note details specific robustness classes defined by IEC standards, focusing on how software solutions can improve application stability during disturbances. It provides practical recommendations for power supply connections for STM8S/STMBA and STM8L families, including decoupling capacitor values and pin configurations to ensure stable operation.
The classes are Class A (no failure), Class B (failure with self-recovery), Class C (external user action needed to recover), and Class D (normal functionality cannot be recovered).
It is recommended to use a capacitor of about 680 nF, as the minimum limit value is 470 nF.
They are designed for standard applications in the 3.3 V to 5 V (+/-10%) supply voltage range.