1. SI8715BC-A-ISR Substitution Conclusion Direct substitution is not recommended. The critical differences lie in the significant degradation of data rate (15Mbps vs. 150Mbps) and signal timing performance (propagation delay of 50ns vs. 16ns, pulse width distortion of 25ns vs. 1ns). This part cannot handle the high-speed digital signals in the original design. The time delay and distortion introduced to the signal after isolation will increase substantially, which could directly cause failures in high-speed communication (e.g., high-speed serial data, PWM control) or lead to system timing violations. Although it offers higher isolation withstand voltage (3750Vrms vs. 2500Vrms) and common-mode transient immunity (35kV/µs vs. 25kV/µs), these advantages do not compensate for its deficiency in core speed performance. It may only be suitable for applications that are extremely insensitive to speed but demand higher isolation strength, such as ultra-low-frequency scenarios.