使用STM8S微控制器的EMC指南.pdfVIP

January 2009 Rev 2 1/11 AN2860 Application note EMC guidelines for STM8S microcontrollers Introduction To meet the demand for more performance, complexity and cost reduction, the semiconductor industry develops microcontrollers with both high density design technology and higher clock frequencies. This has intrinsically increased the potential noise emission and noise sensitivity. Therefore, application developers must now apply EMC “hardening” techniques in the design of firmware, PCB layout and at system level. This application note is intended for application designers who need to reach the optimum level of EMC performance. It gives microcontroller EMC features and compliance standards. This document only concentrates on STM8S features and behaviors. For general information on EMC for ST microcontrollers, refer to the “EMC design guide for ST microcontrollers” application note (AN1709). General recommendations for STM8S devices are summarized in the “Getting started with the STM8S” application note (AN2752). This document also provides basic EMC recommendations. Related documents AN1015: Software techniques for improving microcontroller EMC performance AN1709: EMC design guide for ST microcontrollers AN2752: Getting started with the STM8S RM0016: STM8S microcontroller family Table of contents AN2860 2/11 Table of contents 1 STM8S: designed for EMC robustness . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2 Power supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 3 Layout recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 3.1 Two-layer board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 3.2 Single layer board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 4 EMC characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 5 So