1. VO615A-8X007T Substitution Conclusion The VO615A-8X007T can serve as a substitute, provided core parameters such as electrical isolation, package, and basic current rating remain equivalent. However, design evaluation and adjustment are required. The key differences are as follows: First, its current transfer ratio (CTR: 130%–260%) is notably higher than the original part (100%–200%). This results in stronger output drive capability and higher efficiency under the same input current, but may necessitate re‑verification of stability in control loops sensitive to CTR range. Second, its output transistor maximum collector‑emitter voltage (Vceo: 70V) is lower than the original (80V), posing a risk if the circuit operates near this limit. Finally, its forward voltage (Vf: 1.43V) is higher, requiring recalculation of the current‑limiting resistor under the same drive voltage to ensure proper LED current. In applications not operating at high voltage and where the drive resistor can be adjusted, it represents a high‑performance alternative.