1. SIT8208AI-G2-18E-62.500000X Substitution Conclusion Direct substitution of this model for the original part is viable only under very specific conditions. The key difference lies in the supply voltage, which is reduced from 2.5V for the original device to 1.8V. If the target system operates exclusively on a 1.8V power rail and the clock input level requirements of the downstream load (e.g., FPGA, ASIC) are compatible with 1.8V LVCMOS/LVTTL, this model matches the original in terms of frequency, stability, package, and enable functionality. However, if the original circuit was designed for 2.5V supply, direct replacement will result in insufficient output voltage swing, potentially causing timing errors or signal integrity issues. Therefore, system supply voltage and interface level compatibility must be verified prior to substitution; otherwise, direct replacement is not recommended.