Selection of Decoupling Capacitors for Power Delivery Networks with Multiple Power Ports

摘要

In high-speed printed circuit board (PCB), decoupling capacitors are usually used to reduce noise of power ports. The number and location of capacitors is related to design cost and quality. This paper introduces a method to determine the suitable value and placement of decoupling capacitors for multiple power ports on the same board. Linear network theory is applied to characterize power delivery networks (PDN) with a high accuracy and then a PSO is customized for choosing decoupling capacitors, so that multiple-impedance of all power ports can meet the requirement of the target impedance after placing these capacitors. Finally, a practical board with specific capacitors was simulated and measured. The simulation and experimental results all meet the requirement of target impedance, which confirms the proposed method is valid.