1. TL084CD Substitution Conclusion Caution is advised when directly substituting TL084CD for ADA4004-4ARZ-RL. Key differences include: the amplifier type changes from Standard to J-FET, resulting in very high input impedance (input bias current 30 pA vs. 40 nA), which is suitable for high-impedance sensor interfaces. However, the input offset voltage is significantly higher (3 mV vs. 40 µV), which degrades DC accuracy and signal processing precision. The gain bandwidth product is lower (3 MHz vs. 12 MHz), limiting performance in high-frequency applications. The slew rate is higher (13 V/µs vs. 2.7 V/µs), supporting fast signal processing. Overall substitution feasibility depends on the application: replacement may be acceptable in systems requiring high input impedance and fast response, provided the higher offset voltage and lower bandwidth can be tolerated. Otherwise, it may not be suitable for precision or high-frequency circuits.