1. AD818ARZ Substitution Conclusion The AD818ARZ is physically compatible with the THS4051IDR in both package (8-SOIC) and basic function (voltage feedback amplifier). However, key performance parameters differ significantly: the AD818ARZ offers a higher slew rate (500 V/µs vs. 240 V/µs) and bandwidth (130 MHz vs. 70 MHz), resulting in faster response and superior performance in high‑speed signal processing and high‑frequency applications. Its output current is lower (50 mA vs. 100 mA), which may limit its ability to drive high‑current loads such as low‑impedance transmission lines or heavily loaded circuits. Additionally, the AD818ARZ has a wider supply range (single supply 5 V to 36 V or dual supply ±2.5 V to ±18 V, compared to the THS4051’s single‑supply range of 9 V to 32 V), improving design flexibility, particularly in low‑voltage or dual‑supply systems. It should be noted that input offset voltage (2.5 mV) and bias current (2.5 µA) are specified for the THS4051 but not explicitly provided for the AD818ARZ; if DC precision is critical in the application, additional evaluation may be required. In summary, the AD818ARZ is a viable substitute in video or high‑speed analog circuits where speed and bandwidth are emphasized, but may not be suitable if the original design relies on high output current capability.