1. ISO721MD Substitution Conclusion The ISO721MD matches the original SI8610EC-B-ISR in core communication performance (150Mbps data rate), establishing basic substitution feasibility for general digital signal isolation scenarios. However, careful evaluation is required for demanding applications. First, the isolation voltage rating is reduced from 3750Vrms to 2500Vrms. This reduction in safety margin poses a risk in systems requiring higher electrical isolation strength, such as those needing reinforced insulation or protection against larger surge events. Second, the Common-Mode Transient Immunity (CMTI) is lowered from 35kV/µs to 25kV/µs. This diminished noise immunity in high-noise environments like motor drives or inverters increases the risk of data corruption. Third, the maximum propagation delay increases from 13ns to 16ns. This added delay across the isolation barrier necessitates a re-evaluation of timing margins in high-speed systems with stringent timing control. If the application environment has low noise, the isolation requirement does not exceed 2500Vrms, and sufficient timing margin exists, the ISO721MD can be considered as a cost-reduction or supply chain backup option.