Investigation of noise coupling from switching power supply to signal nets

Noise coupled from switched-mode power supply to signal nets can cause severe signal integrity problems because of the existence of fast switching voltages and currents in the circuit. In this paper, noise coupling mechanism from a synchronous buck converter to a nearby signal trace is studied using a hybrid non-linear model, which combines the synchronous buck converter circuit model and the passive electromagnetic model of the PCB coupling. General design guidelines to mitigate the noise coupling in practical printed circuit board (PCB) designs are provided based on the modeling results.