1. AD746JRZ Substitution Conclusion Direct substitution is not recommended. Although the AD746JRZ shares the same JFET-input architecture and package compatibility with the original part, and even offers superior specifications in certain areas (such as a higher slew rate of 75 V/µs vs. 0.9 V/µs and a wider bandwidth of 13 MHz vs. 1 MHz), its input bias current (110 pA) is 220 times greater than that of the original device (0.5 pA). Furthermore, its quiescent current (7 mA) is approximately 24 times higher than the original's 0.29 mA. In precision applications that rely on extremely high input impedance and minimal input current—such as photodiode amplification, high-impedance sensor interfaces, and integrator circuits—the AD746JRZ would introduce significantly greater bias error and offset voltage. Moreover, its substantially increased power consumption completely violates the original design's micropower requirement, potentially leading to power budget failure and excessive chip heating.