Original Part
Alternative Part
1. AD8684ARZ Substitution Conclusion
Substitution should be approached with caution and is only viable in specific high-precision applications. The AD8684ARZ employs J-FET inputs, featuring an input bias current (6 pA) three orders of magnitude lower than the original part (20 nA), and an input offset voltage (350 µV) significantly lower than the original (2 mV). This results in substantially reduced noise and error in high-impedance sensor signal conditioning or precision DC amplification. However, its supply range (9 V to 36 V) is narrower than the original (3 V to 44 V), particularly with a higher minimum operating voltage, making it incompatible with low-voltage systems operating between 3 V and 9 V. Additionally, its output drive current (12 mA) is only about 44% of the original (27 mA), limiting its ability to drive heavy loads. On the other hand, the part offers higher slew rate (9 V/µs) and gain-bandwidth product (3.5 MHz), making it suitable for higher-frequency signal processing, though note its slightly higher quiescent current (210 µA per channel vs. 180 µA per channel).
2. LM224KAD Substitution Conclusion
Generally substitutable, but with noticeably degraded dynamic performance. The LM224KAD, like the original, is a general-purpose op-amp. Its supply range (3 V to 30 V) covers the lower end of the original specification but has a lower upper limit (30 V vs. 44 V), rendering it unsuitable for applications exceeding 30 V. Its slew rate (0.5 V/µs) and gain-bandwidth product (1.2 MHz) are both lower than the original (2.1 V/µs, 1.8 MHz), leading to slower response and limited bandwidth when processing fast or higher-frequency signals. While its input bias current (15 nA) and offset voltage (2 mV) are comparable to the original, its quiescent current (1.4 mA per channel) is substantially higher than the original (180 µA per channel), which can significantly increase overall system power consumption. Its output drive current (30 mA) is slightly higher, offering marginally better drive capability, though this advantage is limited.
Analysis ID: DA6A-BA4C000
Based on part parameters and for reference only. Not to be used for procurement or production.
SkyChip © 2026, Email: sales@skychip.com