1. AD823AARZ Substitution Conclusion In most general-purpose applications requiring high-speed signal processing, the AD823AARZ can replace the LT1881 with significant performance improvements. However, in specific applications with stringent requirements for DC precision and ultra-low power consumption, a direct substitution is not advisable. The key differences are as follows: First, the slew rate (35 V/µs) and gain-bandwidth product (10 MHz) of the AD823AARZ far exceed those of the LT1881 (0.4 V/µs, 850 kHz). This enables the AD823AARZ to process fast-transient and high-frequency signals without distortion, making it suitable for audio, video, or fast-sensing circuits. Second, its exceptionally low input bias current (1.3 pA), a result of its JFET input stage, provides a significant advantage in current measurement applications involving high-output-impedance sensors, such as photodiodes. Third, its input offset voltage (800 µV) is notably higher than that of the LT1881 (25 µV). In DC-coupled or precision amplification circuits, this will introduce a larger DC error at the output. Fourth, its quiescent current (6.3 mA per channel) is substantially higher than that of the LT1881 (850 µA per channel), representing an unacceptable increase in power consumption for battery-operated devices. The package and supply voltage ranges are essentially compatible.