3 Description

The AT34C02D is designed to support the JEDEC EE1002 and EE1002A Serial Presence Detect (SPD) function used in DDR, DDR2 and DDR3 Dual Inline Memory Modules (DIMM). The AT34C02D provides 2,048 bits of Serial Electrically Erasable and Programmable Read-Only Memory (EEPROM) organized as 256 words of 8 bits each. The device’s cascading feature allows up to eight devices to share a common two‑wire bus.

The first half of the AT34C02D features both permanent and reversible software write protection along with a hardware write-protect option for the entire array, accessible via an external pin. The permanent software write protection is enabled by sending a special command to the device. This protection cannot be reversed once executed. However, the reversible software write protection can be undone by sending and executing a special command. The hardware write protection is controlled by the WP pin state and can be used to protect the entire array, regardless of the software write protection status. The software and hardware write protection features provide users with the flexibility to protect no portion of the memory, the first half of the memory, or the entire memory array depending on the specific needs of the application.

The device is optimized for use in industrial and commercial applications where low-power and low-voltage operations are essential. The device is available in space-saving 8- lead SOIC, 8-lead TSSOP, 8-pad UDFN and 8-ball VFBGA packages. All packages operate from 1.7V to 5.5V.