1. Communication Rate (Clock Frequency): BR24T64FVJ‑WE2: 400 kHz BR24G64FVM‑5TR: 1 MHz The latter supports high‑speed mode (1 MHz), offering 2.5× the data transfer bandwidth of the former, making it suitable for systems with higher read/write speed requirements. When substituting, it is essential to confirm that the host MCU’s I2C peripheral can support and operate stably at 1 MHz. Although high‑speed devices are generally backward‑compatible with standard mode (100 kHz) and fast mode (400 kHz), the clock configuration must be verified during software initialization. 2. Package / Case: BR24T64FVJ‑WE2: 8‑TSSOP‑BJ (width 3.00 mm) BR24G64FVM‑5TR: 8‑MSOP (width 2.80 mm) Both devices share identical pinout definitions, but there are slight differences in package body width and pad dimensions. A direct pin‑to‑pin footprint replacement is not feasible. When replacing with the BR24G64FVM‑5TR, the PCB land pattern must be redesigned to ensure soldering reliability and long‑term mechanical stability. This represents the primary hardware hurdle in the substitution process. Additional Note: The two devices are fully consistent in core functionality (capacity, interface, voltage range, write cycle time) and belong to different series from the same manufacturer, sharing a common lineage in quality and reliability. This provides a solid foundation for substitution. The key to a successful replacement lies in resolving the aforementioned package compatibility issue and validating the stability of high‑speed communication.