4-kb serial presence detect EEPROM for DDR4 SDRAM modules

April 15, 2014 // By Graham Prophet
From Microchip, this SPD EEPROM device is designed to meet new DDR4 standard for PCs and laptops; compatible with previous DDR2/3 platforms and SMBus, it features reversible software write-protect on four individual blocks and faster data rates.

The 4-kb I 2C Serial Presence Detect (SPD) EEPROM, works with the next generation of DDR4 SDRAM modules used in high-speed PCs and laptops, while also supporting older DDR2/3 platforms.

Designed for price-competitive consumer products market and capable of operation across a broad voltage range of 1.7V to 3.6V, the 34AA04 is JEDEC JC42.4 (EE1004-v) Serial Presence Detect (SPD) compliant and is designed to be compatible with DDR4 SDRAM modules. The 34AA04 includes reversible software write protection for each of four independent 128 x 8-bit blocks and supports a new SMBus-compatible bus time out. The device also features a page-write capability of up to 16 bytes of data and three address pins allow up to eight devices on the same bus.

The 34AA04 is backward compatible with existing DDR2 and DDR3 SPD EEPROMs. To ensure backward compatibility, the memory array of the 34AA04 is divided into two separate 256-byte banks to overlay with the architecture of older SPD EEPROM devices. The 34AA04 serves a wide range of applications in the consumer-electronic market such as PCs, laptops, graphic cards and other products.

Microchip has supported the DRAM market with SPD EEPROMs in the previous DDR1, DDR2 and DDR3 platforms and the reversible software write-protect on four individual blocks, faster data rates and SMBus compatibility provides DRAM manufacturers with added flexibility to enable new features in the high-speed PC, laptop and graphic card markets.

Microchip; www.microchip.com/get/CKQL