SLLA529 October 2020 ISO7741
In this article, I discussed the key considerations while choosing signal and power isolation solutions in group isolated and channel-to-channel isolated analog input modules. For group-isolated modules, low propagation delay and small size are important for the signal isolator, and high efficiency at 0.5 W for the isolated power supply. For channel-to-channel isolated modules, the digital isolator must consume very low power, and the isolated power supply must have high efficiency at light loads. Inherent electromagnetic compatibility in the isolation solutions can save the cost and space of X or Y capacitors.