
Chapter 8
resulting situation for front-end OEM converters is simply this — yes, they don’t need to
comply with the legal EMI limits, in fact they need to be much better!
What about dc-dc converters that happen to be positioned deep inside the equipment? Again,
there are no legally applicable EMI/EMC standards for these. Further, since they are likely to
be preceded by various circuits and filters, surge suppressors, fuses, capacitors, inrush
limiters, and so on (e.g. in the front-end power supply), there is usually an adequate (and
fortuitous) EMI barrier already present, that prevents noise from the dc-dc converter from
getting on to the ac mains