1. AD823AARZ Substitution Conclusion The AD823AARZ has limited viability as a substitute and is only acceptable in specific high-speed applications; it is unsuitable for precision DC scenarios. The core differences are as follows: First, the AD823AARZ employs J-FET inputs, resulting in an input bias current (1.3 pA) significantly lower than the BJT input of the LT1884 (150 pA). This is a beneficial characteristic for high-impedance signal sources. Second, however, its input offset voltage (800 µV) is more than an order of magnitude higher than that of the LT1884 (30 µV). In DC or low-frequency amplification, this produces a substantially larger DC error at the output, severely degrading precision. Third, regarding dynamic performance, the AD823AARZ's slew rate (35 V/µs) and gain-bandwidth product (10 MHz) far exceed those of the LT1884 (1 V/µs, 2.2 MHz), making it suitable for high-speed signal processing. The trade-off is a quiescent current (6.3 mA per channel) much higher than the LT1884's (850 µA per channel), leading to significantly increased power consumption. Furthermore, its output drive current (17 mA) is lower than the LT1884's (50 mA). Substitution should only be considered when the application prioritizes high-speed operation with high-impedance signals and can tolerate greater DC error and higher power consumption.