1. Substitution Conclusion for BU7266F-E2 Direct substitution is not recommended. Although the BU7266F-E2 shares the same supply range, input offset voltage, and rail-to-rail output characteristics as the original part, its core performance parameters differ by orders of magnitude: the gain-bandwidth product is only 4 kHz (vs. 1.5 MHz), and the slew rate is a mere 0.0024 V/µs (vs. 0.42 V/µs). This device cannot handle any signals exceeding very low frequencies (e.g., a few Hz) or requiring fast transitions, exhibiting extremely poor dynamic response. It is only suitable for ultra-low-frequency or purely DC applications. Furthermore, its output drive current is only 4 mA (vs. 100 mA), resulting in very weak load-driving capability. It cannot serve as a substitute unless the application exclusively involves processing static or extremely slow-moving DC signals and has an absolute requirement for minimal power consumption (700nA ultra-low quiescent current).