1. LT1013DDR Substitution Conclusion Direct substitution is generally not feasible and should only be considered for non-precision applications insensitive to input bias current. The key discrepancy lies in the input bias current, which is two orders of magnitude higher for the LT1013 (18 nA vs. 50 pA). When amplifying signals from high-impedance sources such as sensors, the LT1013 will introduce significantly larger input error current and offset voltage, severely degrading DC accuracy and stability. Its supply voltage range (5-30V) is also narrower than the original part (4-40V), limiting power supply flexibility. Although it offers a higher gain-bandwidth product (1 MHz) and slew rate (0.4V/µs) for better dynamic performance, this difference is a critical flaw for precision, high-impedance applications that rely on the OP297's ultra-low input current characteristics—such as photodetection or chemical sensor front-ends. Therefore, it is not recommended as a general-purpose replacement.