2. OPA656U/2K5 Substitution Conclusion The OPA656U/2K5 represents an alternative with a different application focus, offering complementary characteristics in input accuracy and bandwidth, though its slew rate is notably lower. The differences are as follows: It employs a JFET input stage with extremely low input bias current (2 pA vs. 2 µA), imposing minimal loading on the signal source. This makes it well‑suited for current‑mode signal acquisition such as photodiode or high‑impedance sensor interfaces, where its DC accuracy is far superior to the original. Its input offset voltage (250 µV) is also much lower than the original’s (2 mV), further improving DC precision. The slew rate (295 V/µs) is substantially lower than the original’s (1500 V/µs), severely limiting its ability to handle high‑frequency large signals (e.g., video signals, fast pulses) and representing the main bottleneck for large‑signal bandwidth. Its gain‑bandwidth product (230 MHz) is close to that of the original, while the ‑3 dB bandwidth (500 MHz) is higher, providing a wider frequency range at unity gain. Similarly, its minimum operating voltage is 8 V.