US Patent 7923710 Digital isolator with communication across an isolation barrier

A signal isolator comprises an isolation barrier, a transmitter, a differentiator, and a recovery circuit. The transmitter is coupled to a first side of the isolation barrier and is configured to receive and convert an information signal to a differential signal that encodes information in the information signal in a single transition edge. The differentiator is coupled to a second side that is isolated from the first side of the isolation harrier and differentiates the differential signal. The recovery circuit is coupled to the differentiator and operates to recover an output information signal based on the information in the single transition edge.