PCB PDN Prelayout Library for Top-Layer Inductance and the Equivalent Model for Decoupling Capacitors

The power distribution network (PDN) of a high-speed printed circuit board requires a high-performance power supply. The total equivalent inductance above the top ground plane is an important part of PDN design and is regarded as L-above. In this paper, an inductance library for different structures of capacitor connections and capacitor sizes has been built, which is essential for PDN design. computer simulation technology (CST) and partial element equivalent circuit method are applied to obtain the shorted pattern design curves at various design data. The shorted pattern design curve means the total equivalent inductance varies with the distance between pad and ground plane. In addition, an approximate shorted model is established for a decoupling capacitor-mounted model, which will be convenient for us to get the inductance of L-above. In this paper, the design curve provides an intuitive guideline in designing PDN and facilitates the industry to choose what they want with consideration of the inductance, space, via numbers, etc.