August 09, 2021 Blog EMI from switching regulators is broken down into radiated and conducted emissions (CE). This article focuses on conducted emissions, which can be further classified into two categories: common-mode (CM) noise and differential-mode (DM) noise. Why the CM-DM distinction? EMI mitigation techniques that are effective for CM noise are not necessarily effective for DM noise, and vice versa, so identifying the source of conducted emissions can save time and money in suppressing it.