My application requires isolated I/O with selectable 5V/3V interface
(changeable on-the-fly using jumper over plug pins). ADuM5201, I hope, can
solve it directly. Is Vsel analog or digital input? Can I use pull-up Vsel to
Viso to select default 5V?
Yes it is a digital input, I would suggest a pull-up/pull down in the 10kohm
range to avoid noise issues. You can directly drive the pin with a digital