The definition of “endurance” (as applied to EEPROMs) contains various words and phrases that require clear definition and understanding. Endurance cycling is a test performed by all manufacturers (and some customers) to determine how many “write cyles” the product will achieve before failing. Microchip defines “endurance” as the minimum number of write cycles the product can be subjected to before it fails. This application note discusses the definition and assessment of endurance, and describes basic guidelines that the designer environmental or operating should observe if he has any control over certain environmental or operating conditions. These guidelines include: keeping the application temperature as low as possible; keeping the application voltage (or the VCC voltage on the EEPROM) as low as possible; writing as few bytes as possible; and using the page write feature whenever possible. With these guidelines applied to the fullest extent, the endurance of EEPROM-based devices can be extended well beyond the specified minimum endurance.