DATA SHEET
2GB Registered DDR2 SDRAM DIMM
EBE21RD4AGFA (256M words × 72 bits, 2 Ranks)
Description
Features
The EBE21RD4AGFA is a 256M words × 72 bits, 2
ranks DDR2 SDRAM Module, mounting 36 pieces of
512M bits DDR2 SDRAM sealed in FBGA (µBGA)
package. Read and write operations are performed at
the cross points of the CK and the /CK. This high-
speed data transfer is realized by the 4bits prefetch-
pipelined architecture. Data strobe (DQS and /DQS)
both for read and write are available for high speed and
reliable data bus design. By setting extended mode
register, the on-chip Delay Locked Loop (DLL) can be
set enable or disable. This module provides high
density mounting without utilizing surface mount
• 240-pin socket type dual in line memory module
(DIMM)
PCB height: 30.0mm
Lead pitch: 1.0mm
Lead-free (RoHS compliant)
• Power supply: VDD = 1.8V ± 0.1V
• Data rate: 667Mbps/533Mbps/400Mbps (max.)
• SSTL_18 compatible I/O
• Double-data-rate architecture: two data transfers per
clock cycle
• Bi-directional, data strobe (DQS and /DQS) is
transmitted /received with data, to be used in
capturing data at the receiver
technology.
Decoupling capacitors are mounted
beside each FBGA (µBGA) on the module board.
• DQS is edge aligned with data for READs; center
aligned with data for WRITEs
Note: Do not push the cover or drop the modules in
order to avoid mechanical defects, which may
result in electrical defects.
• Differential clock inputs (CK and /CK)
• DLL aligns DQ and DQS transitions with CK
transitions
• Commands entered on each positive CK edge; data
referenced to both edges of DQS
• Four internal banks for concurrent operation
(components)
• Burst length: 4, 8
• /CAS latency (CL): 3, 4, 5
• Auto precharge option for each burst access
• Auto refresh and self refresh modes
• Average refresh period
7.8µs at 0°C ≤ TC ≤ +85°C
3.9µs at +85°C < TC ≤ +95°C
• Posted CAS by programmable additive latency for
better command and data bus efficiency
• Off-Chip-Driver Impedance Adjustment and On-Die-
Termination for better signal quality
• /DQS can be disabled for single-ended Data Strobe
operation
• 1 piece of PLL clock driver, 4 piece of register driver
and 1 piece of serial EEPROM (2k bits EEPROM) for
Presence Detect (PD)
Document No. E0794E20 (Ver. 2.0)
Date Published October 2005 (K) Japan
Printed in Japan
URL: http://www.elpida.com
Elpida Memory, Inc. 2005
ELPIDA [ ELPIDA MEMORY ]
