1. ISL28213FUZ-T7 Substitution Conclusion Direct substitution is not viable. Although the package is pin-compatible and the supply voltage range matches, there are fundamental differences in key performance parameters that could prevent the original circuit from functioning correctly. The quiescent current of the ISL28213 (90 µA per channel) is two orders of magnitude higher than that of the original part (700 nA per channel), which would drastically increase standby power consumption in battery-powered applications. Its gain-bandwidth product (2 MHz) and slew rate (1 V/µs) far exceed those of the original device (12 kHz, 0.005 V/µs), completely altering the circuit bandwidth and dynamic response. This could lead to stability issues such as oscillation, increased noise, or loss of intended filtering characteristics in circuits originally designed for low bandwidth. While its higher output drive capability (22 mA) is an advantage, it was not a critical requirement of the original design. Consideration may only be given if the system is extremely insensitive to power consumption and can accept entirely different AC characteristics; otherwise, a complete circuit redesign and verification are necessary.