In the context of noise, analog and digital systems are thought of respectively as receivers and transmitters of electrical noise. Switched-mode power converters present a mixed-mode environment. Controllers, be they digital or analog in nature, are set alongside switched power devices. Power components are modular: to a great extent the OEM (original engineering manufacturer) will have taken great pains to mitigate the effect of noise sources internal to the module, sometimes with mixed results. If not countered, self-noise of a power module is often sufficient to affect signaling affecting control of power within the component. Implementing a system with such products involves introducing measures that the OEM should provide in applications literature. Module self-noise can be reduced with the introduction of suitable external components that are selected and arranged in a board layout designed to introduce minimal parasitics. The components will interact with the printed circuit layout, which means that noise performance is not something that can be automatically guaranteed. In almost every case that such provisions are offered, there will be reference made to engineering standards for CE (conducted emissions) such as CISPR22 or EN61000-4-6. These two standards contain clear definitions and detailed test arrangements that can be used to authenticate a power system’s emission and susceptibility characteristics. CE standards focus on conducted electrical noise that propagates to the input power source. Noise appearing at the output side of the system can also be attenuated, with either CM (common-mode) or DM (differential-mode) filtering or a combination of the two, just as for input-source-terminated CE. It can be argued that using power components facilitates noise control design in the integrated application. Although it is generally not possible to integrate all the suppression elements in a power component, the manufacturer will recommend the minimum effective external measures required in an optimal board layout. Given the nature of the varied types of applications being worked on by customers, applications engineers at the OEM can often be called upon to determine adequacy of current noise control strategies and suggest ways to suppress noise. This paper illustrates such an example.