VPX power supplies and EMI filters

Electro-magnetic interference (EMI) filters are critical components in any electrical design, especially in support of military systems requiring partial or complete qualification to MIL-STD-461. EMI filters are designed to reduce high frequency conducted and radiated electronic noise which may create interference with other electrical devices. Embedding EMI filters into the power supply, a potential signal source, is a key feature in any power supply design.

This holds true in the constrained volume of 3U and 6U form factors. Some VPX power supply designs do not use enough , thereby potentially creating a litany of system-level challenges for which the integrator would ultimately bear responsibility.

One such challenge would be the need for a second card slot in a VPX chassis to host a stand-alone EMI filter. In many upgrade or retrofit programs, two card slots are not available to the integrator for a power supply and EMI filter, requiring migration to a larger chassis and space claim challenges.

The integrator should be cautious to source a VPX power supply with an appropriately designed embedded EMI filter.

To learn more about the advantages and characteristics of VPX power supplies, read a white paper from Milpower Source, titled “VPX Power Conversion Guide.”

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