1. M24C64-DFDW6TP Substitution Conclusion From a core parameter standpoint, the M24C64-DFDW6TP is fully aligned with the original part (24FC64FT-I/ST) in terms of memory density (64 Kbit), interface (I²C), operating voltage range (1.7V–5.5V), package (8-TSSOP), and write cycle time (5 ms), establishing direct hardware compatibility. The primary deviation lies in the access time (450 ns vs. 400 ns), where the ST variant exhibits a slightly higher data output delay. However, for the vast majority of I²C applications—particularly those operating at clock frequencies ≤1 MHz—this discrepancy is negligible and will not impact communication integrity. It should be noted that the manufacturer change may introduce secondary characteristic variances, such as in internal write cycle management or ESD protection ratings. Therefore, it is recommended to validate long-term stability and protocol compatibility within the specific application prior to implementing the substitution.