Whenever engineers who need or use isolation amplifiersget together and talk about the improvements they wouldlike to see most, the big three—cost, size, performance—arelikely to be mentioned. The industrial or medical equipmentmanufacturer often has to make a choice of either buying anisolation amplifier or building his own. Cost is the keycriterion for such a decision, but there are others as well. Forexample, the multichannel analog system designer usuallyruns into printed circuit board space limitations, since healmost always requires a lot of data channels on each PCboard.