I'm currently looking into various DC DC converters and was confused that the Meanwell DDR-60 series only shows a typical rating but says nothing about the efficiency at idle. From AC/DC converters I'm used to have a curve that starts at idle and maybe 70% and goes to 100% load, having the peak at ninetee something.
It’s similar to AC-DC. From a simplistic perspective, efficiency at idle will be 0% because the converter itself still uses some power, then efficiency increases with load since the converter overhead becomes less significant as the useful work increases. Googling “dc dc converter efficiency curve” gives plenty of results.
They might be willing to spec it as "quiescent current" (current drawn at 0 load) even if they don't provide a full curve. Annoying that it's not on the datasheet.