Resonant-free PDN design®

The design of power distribution networks (PDNs) on printed circuit board (PCB) structures, or even on interconnect structures inside IC packages, typically results, with or without decoupling capacitors added, in a network full of impedance resonances. These resonances functionally hamper fast digital and RF designs from several MHz up to the GHz-range onwards and are the root cause for many EMC issues. These resonances are caused both by the physical size and geometry of the PCB and the decoupling as well as the loading components added to that PCB. Utilizing the characteristic impedance of the adjacent supply and ground layers correctly, results in a resonant free supply PDN with an impedance which can be made very low over an extremely broad frequency range. This, in combination with `Kelvin contact' decoupled ICs, assures that the low impedance of the PDN can be maintained and multiple decoupling capacitors are no longer needed near to the IC pins. This offers great advantages for PCB space allocation and opens opportunities to more efficient routing. This extended concept has been verified by simulations. Additional measurements were taken to validate the concept.