An apparatus and method is described herein for reducing noise in a power distribution network for an interface. The power distribution network is characterized. And based on that characterization, worst case patterns for the interface are predicted and avoided. As one example, characterization includes providing a stimulus, such as a step function stimulus, and determining a mathematical function response, such as a step function response. Then, based on the step function response, a resonant frequency for the power distribution network is determined; from which patterns that cause the resonant frequency are identified/predicted. And when identified patterns are detected, they are scrambled or manipulated to avoid causing a worst-case noise scenario in an interface's power distribution network.