Digital ICs/DSP: Reduced-Height DDR2 DIMMs Ease Airflow In Low-Profile Systems

A low-profile second-generation double-data-rate registered dual-inline memory module (DIMM) stands only 0.72 in. (18.29 mm) above the circuit board. The low height makes the DIMM a good solution for system memory in 1U blade servers and in network switching systems. Available in a 32-, 64-, or 128-Mword by 72-bit configuration, the 240-contact modules are based on 256-Mbit, 512-Mbit, and 1-Gbit DDR2 SDRAMs that are housed in fine-pitch ball-grid-array packages. Data-transfer speed grades include PC2-3200, 4300, 5300, and 6400 (200, 266, 333, and 400 MHz, respectively). The low-profile design allows the modules to be vertically mounted, improving the airflow in the low-profile enclosures. Prices start at $90 apiece for the 256-Mbyte module and go up to $325 each for the 1-Gbyte unit in quantities of 1000 units.