In this application note from Silicon Labs, we cover how ensuring safety in end-user applications requires high voltage circuits (i.e., circuits with >30 VAC) to be physically separated from the safety extra-low voltage circuits (SELV is a circuit with <30 VAC) by a certain distance (creepage/clearance). If a component, such as a digital isolator, straddles this isolation barrier, it must meet those creepage/clearance requirements and provide a sufficient high-voltage breakdown protection rating (commonly referred to as working voltage protection). Refer to the end-system specification (61010-1, 60950-1, 60601-1, etc.) requirements before starting any design that uses a digital isolator. These standards dictate both the working voltage requirement and the creepage/clearance distance spacing necessary to deem an end product safe for end-customer use.
