M378T3354BG Datasheet, PDF (17/23 Pages) Samsung semiconductor – DDR2 Unbuffered SDRAM MODULE

256MB,512MB,1GB Unbuffered DIMMs
Electrical Characteristics & AC Timing for DDR2-533/400 SDRAM
(0 °C < T_CASE < 95 °C; V_DDQ = 1.8V + 0.1V; V_DD = 1.8V + 0.1V)
DDR2 SDRAM
Refresh Parameters by Device Density
Parameter
Symbol
256Mb 512Mb 1Gb 2Gb 4Gb Units
Refresh to active/Refresh command time tRFC
75
105 127.5 195 tbd ns
Average periodic refresh interval
0 °C ≤ T_CASE ≤ 85°C
7.8
7.8
7.8
7.8 7.8
µs
tREFI
85 °C < T_CASE ≤ 95°C
3.9
3.9
3.9
3.9 3.9
µs
Speed Bins and CL, tRCD, tRP, tRC and tRAS for Corresponding Bin
Speed
DDR2-533(D5)
DDR2-400(CC)
Units
Bin (CL - tRCD - tRP)
4-4-4
3-3-3
Parameter
min
max
min
max
tCK, CL=3
5
8
5
8
ns
tCK, CL=4
3.75
8
5
8
ns
tCK, CL=5
-
-
-
-
ns
tRCD
15
15
ns
tRP
15
15
ns
tRC
55
55
ns
tRAS
40
70000
40
70000
ns
Timing Parameters by Speed Grade
(Refer to notes for informations related to this table at the bottom)
Parameter
Symbol
DQ output access time from tAC
CK/CK
DQS output access time
from CK/CK
tDQSCK
CK high-level width
tCH
CK low-level width
tCL
CK half period
tHP
Clock cycle time, CL=x
tCK
DQ and DM input hold time tDH
DDR2-533
min
max
-500
+500
-450
+450
0.45
0.45
min(tCL,
tCH)
3750
225
0.55
0.55
x
8000
x
DDR2-400
min
max
-600
+600
-500
+500
0.45
0.45
min(tCL,
tCH)
5000
275
0.55
0.55
x
8000
x
DQ and DM input setup
tDS
time
100
x
150
x
Units Notes
ps
ps
tCK
tCK
ps
20,21
ps
24
ps
15,16,
17
ps
15,16,
17
Rev. 1.2 Jan. 2005