1. Substitution Conclusion for 71V65603S133BQG From the perspectives of core functionality, package, and electrical interface, the 71V65603S133BQG can serve as a direct replacement for the original part 71V65703S75BQG. Both devices share identical specifications for memory density (9Mbit/256Kx36), interface (parallel), operating voltage (3.3V±5%), and physical package (165-CABGA), ensuring physical and fundamental electrical compatibility. The key difference lies in the enhanced performance specification: the substitute part features a faster access time of 4.2ns (corresponding to a clock frequency of 133MHz), a significant improvement over the original part's 7.5ns. With the same hardware connections, the system will achieve higher data throughput. However, the designer must prioritize verifying timing compatibility to ensure the original system's controller timing (e.g., setup/hold times) can accommodate the faster SRAM or that the new SRAM can be configured to operate at the original timing. Furthermore, attention should be paid to potential differences implied by the suffix variation, such as temperature grade or other characteristics. Consulting the detailed datasheet for final confirmation is recommended.