Power Distribution Networks
Power Distribution Networks (PDNs) form the critical infrastructure that delivers clean, stable power from voltage sources to integrated circuits throughout electronic systems. While often overlooked in favor of high-speed signal routing, the PDN fundamentally determines system reliability, performance, and signal integrity. A poorly designed PDN causes voltage droop, ground bounce, electromagnetic interference, and timing errors that can render even the most sophisticated digital designs non-functional.
Modern high-speed digital systems present formidable PDN challenges. Processors and FPGAs operating at multi-gigahertz clock rates can draw hundreds of amperes with current transients occurring in nanoseconds. These rapid current changes interact with even small parasitic inductances to create voltage disturbances that propagate throughout the system. Effective PDN design requires understanding the complete power delivery chain from voltage regulators through PCB planes and traces to on-die power grids, considering impedance characteristics across frequencies from DC to several gigahertz.
The field encompasses voltage regulation, decoupling and bypassing strategies, power plane design, target impedance methodology, and the integration of these elements into a coherent power delivery architecture. As supply voltages continue to decrease while current demands increase, PDN design becomes ever more critical and challenging.