Noise coupling analysis for high speed differential trace crossing switching voltage regulator area

Switching voltage regulators are prevalent in electrical systems as power solution. The periodic transition edges of voltage and current in switching voltage regulator generate power noise, which can be coupled to the adjacent high-speed signal lines when the coupling path is effective. This paper introduces a failure case on high-speed signal caused by power noise. By simulation and analysis, it explains the phenomenon of differential mode power noise on differential high-speed signal traces, explores the noise coupling mechanism of signal traces crossing switching voltage regulator area and discusses the mitigations of this power noise coupling issue. The measurement results show proper modifications can effectively reduce the power noise.