The AT24C01/02 provides 1024/2048 bits of serial electrically erasable and programmable read-only memory (EEPROM) organized as 128/256 words of 8 bits each.The device is optimized for use in many industrial and commercial applications where low-power and low-voltage operation are essential.
Specifications

The AT24C04 provides 4096 bits of serial Electrically erasable and programmable read-only memory (EEPROM) organized as 512 words of 8 bits each.The device is optimized for use in many industrial and commercial applications where low-power and low-voltage peration are essential.             Specifications