6 EMI Considerations

In switching power supplies, electromagnetic interference (EMI) noise is unavoidable due to the switching actions of the semiconductor devices and resulting discontinuous currents. This section defines and discusses electromagnetic interference and describes ways to mitigate its effects.

EMI/RFI Board Design:SNLA016

This application report introduces EMI and describes how it relates to the performance of a system. Examples of inter-system and intra-system noise and present techniques that can be used to ensure EMI compatibility throughout a system and between systems are shown.

Layout Tips for EMI Reduction in DC/DC Converters:SNVA638

This application note explores how the layout of a DC/DC power supply can significantly affect the amount of EMI that it produces. It discusses several variations of a layout, analyzes the results, and provides answers to some common EMI questions such as whether or not to use a shielded inductor.

Simple Success with Conducted EMI from DC/DC Converters: SNVA489

Conducted and radiated EMI arise from the normal operation of switching circuits, and EMI control is one of the main challenges in SMPS design. This application report focuses on the theory and mitigation techniques of the conducted portion of EMI.

Minimizing Ringing at the Switch Node of a Boost Converter: SLVA255

This application report explains how to use proper board layout and/or a snubber network to reduce high-frequency ringing at the switch of a boost converter. The same principle applies to buck-boost converters.

Layer Design for Reducing Radiated EMI of DC to DC Buck-Boost Converters: SLVAEP5

This application note gives guidelines for improving EMI performance for PCB design of TPS63xxx devices. The main radiation sources for non-inverting buck-boost converters are briefly explained. Three different solutions are proposed and their effectiveness is validated by anechoic chamber measurements.