Typical power supplies consists of a mixture of power components handling switching voltages and currents of large value and amplitude, and small signal components handling low-level analog signals, all in close proximity. Laying out a power supply board entails
positioning and routing the components in such a way that the high-power signals do not corrupt the low-power signals and cause poor performance. A poor layout will lead to the generation of unwanted voltage and current spikes which will cause not only noise to appear on DC voltages in the supply, but also EMI to radiate to adjacent equipment. Thus proper layout techniques are critical to achieving optimal performance of a power supply.
This article describes the most important of these techniques.