Free EMC filter guide November 1st 2005 Selecting an EMC filter based upon typical test house protocols employing a conventional 50 ohms source and 50 ohms load impedence test does not guarantee the connected product will not cause (or suffer) problems in the field due to conducted emissions (or immunity).
According to REO UK, such tests only provide a rudimentary method of assessing the relative merits of one filter against another.
They do not provide an effective means of selecting a filter with the intention of ensuring compliance with EMC emission. The test data should reflect a supply/load impedance mismatch, which is more typical of everyday operating conditions.
A free 22-page guide on EMC filters and their application is available from REO. More articles from REO (UK) Ltd: |