This document serves as a guide for designing video graphics systems with a focus on Electromagnetic Compatibility (EMC) and reducing Electromagnetic Interference (EMI). It addresses the challenges of incorporating low-cost, high-performance video RAM-DACs into personal computers and plug-in boards while adhering to government limits, such as the U.S. FCC Part 15.
The note covers key areas including international regulatory bodies and their limits, identification of system noise sources like crystal oscillators and switching power supplies, and practical PCB layout and design techniques. It specifically discusses component placement, grounding, shielding, filtering, and provides a practical example of a VGA board design associated with FCC testing.
The limit is 100 uV/Meter when measured at a distance of 3 meters.