The 93C66B-E/MS part is an electrically erasable and programmable read-only memory (EEPROM) device produced by Microchip Technology. The device has a capacity of 8Kbits, organized as 4K x 16 bits. It has a low supply voltage of 2.7V to 5.5V, making it ideal for a wide range of applications. The device features a maximum operating temperature of +125°C, and a typical access speed of 55ns. The 93C66B-E/MS includes hardware and software data protection features such as multiple control signals, high endurance cycles, and autoselect and nonvolatile write protection. It also includes a factory ROM code for self-programming the device.