1. 6N136S1(TB) Substitution Conclusion The 6N136S1(TB) is generally a viable substitute for the original part, with attention required to its switching time characteristics. Its turn-off time (300ns) is significantly faster than the original (600ns), which is advantageous for high-frequency or fast turn-off applications. However, its turn-on time (350ns) is slightly slower than the original (200ns), potentially impacting scenarios with extremely stringent response speed requirements. All other key parameters, including isolation voltage (5000Vrms), CTR range (19%~50%), output current (8mA), and package, are identical. The forward voltage (1.45V) is marginally lower than the original (1.5V), but this falls within normal operational variance. Direct substitution is acceptable if the system prioritizes fast turn-off and can tolerate the slightly longer turn-on delay; otherwise, timing compatibility should be verified.