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EBE21UE8ACFA Datasheet, PDF (1/29 Pages) Elpida Memory – 2GB Unbuffered DDR2 SDRAM DIMM
DATA SHEET
2GB Unbuffered DDR2 SDRAM DIMM
EBE21UE8ACFA (256M words × 64 bits, 2 Ranks)
Specifications
• Density: 2GB
• Organization
 256M words × 64 bits, 2 ranks
• Mounting 16 pieces of 1G bits DDR2 SDRAM sealed
in FBGA
• Package: 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: 800Mbps/667Mbps (max.)
• Eight internal banks for concurrent operation
(components)
• Interface: SSTL_18
• Burst lengths (BL): 4, 8
• /CAS Latency (CL): 3, 4, 5, 6
• Precharge: auto precharge option for each burst
access
• Refresh: auto-refresh, self-refresh
• Refresh cycles: 8192 cycles/64ms
 Average refresh period
7.8µs at 0°C ≤ TC ≤ +85°C
3.9µs at +85°C < TC ≤ +95°C
• Operating case temperature range
 TC = 0°C to +95°C
Features
• Double-data-rate architecture; two data transfers per
clock cycle
• The high-speed data transfer is realized by the 4 bits
prefetch pipelined architecture
• Bi-directional differential data strobe (DQS and /DQS)
is transmitted/received with data for capturing data at
the receiver
• DQS is edge-aligned with data for READs; center-
aligned with data for WRITEs
• Differential clock inputs (CK and /CK)
• DLL aligns DQ and DQS transitions with CK
transitions
• Commands entered on each positive CK edge; data
and data mask referenced to both edges of DQS
• Data mask (DM) for write data
• 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
Document No. E1057E20 (Ver. 2.0)
Date Published November 2007 (K) Japan
Printed in Japan
URL: http://www.elpida.com
Elpida Memory, Inc. 2007