1. MC4558CDT Substitution Conclusion Substitution is not recommended. The MC4558CDT exhibits significant performance deviations from the original OP285GSZ in critical parameters, and a direct replacement would severely degrade system performance. The core differences are: 1) Input offset voltage (1mV vs. 35µV). The MC4558CDT's poor DC precision introduces a baseline error nearly 30 times greater than the original, making it unsuitable for high-gain amplification or precision sensor signal conditioning. 2) Slew rate and bandwidth (2.2V/µs & 5.5MHz vs. 22V/µs & 9MHz). The MC4558CDT's large-signal handling capability and frequency response are significantly inferior to the original, causing severe distortion in circuits requiring fast transients or higher frequency signals. Although its supply range (4V-40V) and quiescent current (2.3mA) are compatible or even better, the substantial disadvantages in these key parameters render it incapable of fulfilling the OP285GSZ's intended design role.