There are two major frequency bands of interest for the PDN: first dip and die/package resonance. The first dip is associated with a clock edge and occurs because a certain amount of charge is drawn by the load with a rise time on the order of 100pSec. All the charge consumed in this time period must already be in capacitance on the die because the package is too slow to respond. At a much lower frequency, the on-die capacitance resonates with the package inductance, typically around the 30 MHz band. The PDN resonant system involves the die, package and board. It is not possible to analyze the die/package/board resonance problem without viewing the PDN as a system. Tools to analyze the 30 MHz band problem may be related to but are different from the tools required for the GHz problem.