1. LMV321IDBVT Substitution Assessment The LMV321IDBVT demonstrates performance superior or comparable to the original TSV851ILT across several key parameters. It offers a higher slew rate (1 V/µs vs. 0.7 V/µs), enabling faster large-signal response. Its lower input bias current (15 nA vs. 27 nA) and lower input offset voltage (1.7 mV vs. 4 mV) enhance DC accuracy and reduce error in high-impedance circuits. However, its gain bandwidth product (GBP) is lower (1 MHz vs. 1.3 MHz), which may limit high-frequency, small-signal amplification performance. Additionally, its minimum supply voltage is slightly higher (2.7 V vs. 2.5 V), potentially making it incompatible in extremely low-voltage applications. Quiescent current is identical (130 µA), and the package is compatible (both SC-74A, SOT-753). While output current is not explicitly specified, the typical LMV321 output drive capability is likely lower than the TSV851's 70 mA, affecting its ability to drive heavy loads. In summary, the LMV321IDBVT is a viable substitute if the application is not stringent on bandwidth and ultra-low voltage operation, and places higher priority on input precision and transient response speed. 2. APX321WG-7 Substitution Assessment The APX321WG-7 matches or exceeds the original TSV851ILT in most critical parameters. It features a higher slew rate (1 V/µs vs. 0.7 V/µs) for faster signal processing. Lower input bias current (15 nA vs. 27 nA) and input offset voltage (1.7 mV vs. 4 mV) improve measurement and amplification accuracy. Its quiescent current is lower (110 µA vs. 130 µA), aiding in reduced system power consumption. Output current is higher (90 mA vs. 70 mA), enhancing load-driving capability. The supply voltage range is identical (2.5 V to 5.5 V), and the package is compatible (SC-74A, SOT-753). The primary difference is a lower gain bandwidth product (1 MHz vs. 1.3 MHz), which may slightly impact performance in high-frequency applications, though this is often negligible for general-purpose op-amp use cases. Overall, the APX321WG-7 is an excellent direct replacement, particularly in applications demanding low power consumption, high output drive, and good input characteristics, resulting in high substitution feasibility.