Investigation into PCB Routing Loss for Coupled Inductor Based VR (Voltage Regulator) Design in Server Computing System

Coupled inductor is one appealing technology to improve transient response and reduce output decoupling significantly in interleaved multi-phase voltage regulators (VRs). One well known problem is that coupled inductor winding structure causes PCB routing path longer than discrete inductor design. This paper investigates possible PCB routing schemes for coupled inductor and conducts a fair and quantitative comparison with discrete inductor in a server VR design. Simulation and measurement are also conducted to verify the analysis.