The ECF40 achieves a very impressive best case efficiency of 93%. This high efficiency is not normal for power levels around 40 W but is necessary to enable XP Power to offer the size and derating performance that have already mentioned. Perhaps most impressively the design ensures that the efficiency level remains high across almost the entire load range, at any input voltage between 90 and 264 VAC, and with any of the output versions, including the higher current 12 V model. This is a key feature of the ECF40 providing real benefits when integrated in the end equipment.