Dear bess,
Thanks for yout mail.
Since both of these parts are ORIGINAL MOTOROLA parts, we have very limited data/resource to confirm the difference.
Based on our engineer's confirmation. the last "EI" and “FN” stands for the package，
MC145572AFN package is PLCC, not no info about MC145572AEI .
https://www.nxp.com/docs/en/user-guide/MC145572.pdf
Pls refer to the datasheet (page 197) for the details, thank you.
