Definition

Power Distribution Network (PDN) encompasses all elements delivering power from the supply to IC power pins: PCB power/ground planes, decoupling capacitors, VRMs (voltage regulator modules), and interconnecting traces and vias. PDN impedance must remain below a target value (Ztarget = ripple voltage tolerance / transient current) across all frequencies of interest. PDN analysis evaluates plane resonances, capacitor effectiveness, via inductance, and overall impedance profile. Poor PDN causes voltage droop, increased noise, and signal integrity problems.