1. LM2904YST Substitution Conclusion The LM2904YST, as a general-purpose operational amplifier, carries significant risk when used as a direct replacement for the audio‑optimized BA8522RFVM‑TR. It may only be considered in non‑critical audio or signal‑processing applications where performance requirements are extremely low. The core differences are as follows: the LM2904YST’s gain‑bandwidth product (700 kHz) and slew rate (0.6 V/µs) are far lower than those of the BA8522 (6 MHz, 3 V/µs). This limits its ability to provide high‑gain amplification within the audio frequency band, potentially leading to high‑frequency distortion and sluggish dynamic response. Moreover, its input offset voltage (2 mV) is substantially higher than that of the BA8522 (100 µV), which can introduce greater DC error and signal distortion, degrading audio fidelity. Although the LM2904YST offers advantages such as low power consumption (700 µA) and automotive‑grade qualification (AEC‑Q100), its key performance parameters do not meet the basic requirements for audio‑amplification quality intended by the original part. Therefore, direct substitution is not recommended in designs where sound quality or high‑frequency performance is important.