Ground bounce

That reduces the ground bounce caused by the internal bond wires of the IC, but getting the entire converter to work properly requires a deep understanding of the role played by the PCB, its contribution to ground bounce, noise, and so on. 

Ground bounce noise Groundbounce 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 system 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. 

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