1. AD8544WARZ-R7 Substitution Conclusion The AD8544WARZ-R7 can serve as a drop-in replacement for the TS1854IDT, as both are quad rail-to-rail output op-amps in compatible packages. However, the following key differences must be considered: its higher slew rate (0.92 V/µs) and gain bandwidth product (1 MHz) provide superior large-signal response and bandwidth, making it suitable for applications with higher dynamic requirements. The extremely low input bias current (4 pA) significantly improves accuracy in high-impedance signal conditioning, whereas the TS1854IDT’s 16 nA bias current may introduce greater error. On the other hand, the AD8544WARZ-R7 has a narrower supply voltage range (2.7 V to 5.5 V) and cannot support the TS1854IDT’s 1.8 V low-voltage operation. Additionally, its lower output drive current (30 mA vs. 48 mA) limits capacitive or low-impedance load driving capability. If the system operates above 2.7 V and does not require high output current, the AD8544WARZ-R7 offers advantages in performance and power consumption (45 µA per channel). Otherwise, compatibility should be re-evaluated.