Application note(PDF) specific on microcontroller EMC from ST Microelectronics.
Electromagnetic compatibility (EMC) must be taken into account at the very beginning of a project as the cost of correcting an EMC problem encountered at the start of production can be far greater that the cost of a detailed EMC study during the development phase of an application.
The use of microcontroller-based systems is increasingly wide-spread, especially in such areas as consumer, industrial and automotive applications, where the drive for cost reduction is the common trend. This emphasis on cost reduction and the increasing complexity of such systems requires the manufacturers of semiconductor components to develop highly integrated, single chip, high operating frequency microcontrollers using the highest density technology possible. Unfortunately, for semiconductor structures, the higher the density and the faster the operation, intrinsically the higher the level of electrical noise generated, and the increased sensitivity to spikes induced from external noise. Therefore, the PCB layout, the software and the system must now apply EMC “hardening” techniques in their design.
This note aims to provide guidelines for designers of microcontroller-based applications so that the optimum level of EMC performances can be achieved.