2. AD8682ARZ Substitution Conclusion This device can serve as an upgrade replacement in applications demanding high precision, high input impedance, and superior dynamic performance; however, a critical barrier exists, preventing it from being a direct drop-in substitute. Compared to the original part, the differences are as follows: It employs JFET input technology, resulting in very low input bias current (6 pA vs. 45 nA). This makes it ideal for interfacing with high-impedance sensors like photodiodes or pH electrodes, introducing negligible error. Its gain-bandwidth product and slew rate (3.5 MHz, 9 V/µs) are far superior to the LM358, offering excellent dynamic performance. However, its minimum supply voltage requirement is 9 V (the LM358 can operate down to 3 V), rendering it completely non-functional in single-supply 5 V or 3.3 V systems—this is the primary substitution obstacle. Furthermore, its input offset voltage (350 µV) is superior, providing higher accuracy. This upgrade should only be considered if the original circuit's supply voltage meets the requirement (≥9 V) and there is a need to enhance precision and speed.