1. AD818ARZ Substitution Conclusion Direct substitution is not recommended. Although both devices share the same package (8-SOIC) and manufacturer, there are significant differences in key electrical parameters. Direct replacement may lead to degraded system performance or functional failure. The primary distinctions are as follows: The AD818ARZ offers substantially higher bandwidth (130 MHz) and slew rate (500 V/µs) compared to the LT1354 (12 MHz, 400 V/µs). While this makes it better suited for high‑speed video or pulse‑amplification applications, it also increases the risk of stability issues such as oscillation. A more critical drawback is its quiescent supply current (7 mA), which is seven times that of the LT1354 (1 mA). This would significantly increase system power consumption, making it unacceptable for portable or low‑power designs. Furthermore, the AD818ARZ does not provide specified input bias current and offset voltage parameters, introducing risk in applications where the original design requires precise DC performance.