Those are probably great if you can afford them. I've never had the budget for them in a production design, so haven't played with them much. Standard practice

Those are probably great if you can afford them. I've never had the budget for them in a production design, so haven't played with them much. Standard practice these days is just to toss a full ADC on the other side of the barrier and then isolate the SPI bus (or what-have-you). A few ADCs have the isolation built in, but for others there's stuff like TI's ISOW7841, which have 4 isolated digital lines plus isolated power in one package. It's all kind of expensive when added up, but it's cheaper than the old style analog isolation amplifiers, and you'll usually get more than one ADC channel once everything's together, so you win as soon as you want two signals to cross the barrier.