2. SI8610AB-B-ISR Substitution Conclusion This part can only be considered as a substitute in very low-speed, timing-insensitive applications; it is not viable as a general-purpose replacement. The most critical differences are the drastically reduced data rate (1Mbps vs 150Mbps), significantly increased propagation delay (35ns vs 16ns), and substantial pulse width distortion (25ns vs 1ns). It is completely incapable of handling medium-to-high-speed digital signals, severely limiting system bandwidth and introducing unacceptable timing errors. Although its isolation voltage (2500Vrms) and common-mode immunity (35kV/µs) are comparable to or better than the original part, the extremely low speed and poor timing performance render it unsuitable for the vast majority of scenarios targeted by the original design.