Principles of Power Integrity for PDN Design--Simplified: Robust and Cost Effective Design for High Speed Digital Products

Chapter 8. The PDN Ecology

So far we have looked at the principles behind the behavior of the PDN and its components. The most important property of the components of the PDN is how they interact. The capacitance of an element can interact in a parallel combination with the inductance of another element. This results in a parallel resonance and a peak impedance.

Although the industry focuses much attention on how low an impedance we can obtain by adding capacitors to a PDN, the peak impedances are what cause the real problems. Interactions between components are generally what create these peaks. This means we must analyze the entire PDN system as a whole. This is the PDN ecology.

The real problems and design strategies are based on the interactions ...