DC power bus noise isolation with power islands

Segmented power planes are often used for DC power bus noise isolation in multi-layered printed circuit board (PCB) designs. To achieve a desirable noise isolation, different power plane segmentations can be used. A suitable modeling approach, as well as measurements, were employed to study the power bus isolation with several power plane segmentation configurations. The studied geometries included power island designs connected with a conducting bridge, a ferrite bead, and a /spl pi/-filter. In addition, different conducting bridge widths and power island gap widths were analyzed, and compared. The modeled and measured results show that power plane segmentations with proper designs can result in significant power bus noise isolation.