AT24CS01/02/04/08 I2C Compatible Serial EEPROMs Microchip AT24CS01/02/04/08 I2C Compatible Serial EEPROMs provide 1024/2048/4096/8192 bits of Serial Electrically Erasable and Programmable Read-only Memory (EEPROM) organized as 128/256/512/1024 words of eight bits each. The device is optimized for industrial and commercial applications where low-power and low-voltage operations are essential. The AT24CS01/02/04/08 provides the additional feature of a factory-programmed, guaranteed unique 128-bit serial number while maintaining all the traditional features available in the 1-Kbit/2-Kbit/4-Kbit/8-Kbit Serial EEPROM. The time-consuming step of performing and ensuring true serialization of products on a manufacturing line can be removed from the production flow by employing the CS Series Serial EEPROM. The 128-bit serial number is programmed and permanently locked from future writing during Microchip production. Further, this 128-bit location does not consume any of the read/write area of the 1-Kbit/2-Kbit/4-Kbit/8-Kbit Serial EEPROM.