ground bounce nois
ground bounce occurs when a large number of semiconductor circuit components are mounted on a
common semiconductor chip substrate, so that they are imperfectly
insulated from each other. In normal operation the substrate should act
as an insulator; however, during certain unusual fluctuations in signal
levels, the systems power and ground connections can experience
fluctuations, which affect the performance of each component in a random
way that has the characteristics of noise, much like capacitive
coupling.