The 25LC640-I/P manufactured by Microchip is a 64K-bit, 8K x 8 serial-SPI (Serial Peripheral Interface) electrically erasable programmable read-only memory (EEPROM) in 8-pin plastic dual-in-line package (PDIP). It operates on a voltage range of 3.3V or 5V and can store up to 512K (64K x 8) of data. It can be used for storing non-volatile data, such as configuration settings, product codes, calibration data, etc. The 25LC640-I/P has high-speed SPI bus access times of 20MHz (maximum). It has an endurance of up to 1 million write/erase cycles and an operating temperature range of -40°C to 125°C. It is ideal for a wide range of embedded applications, such as sensor networks, medical instrumentation, industrial automation, etc.