M393T3253FG Datasheet, PDF (13/18 Pages) Samsung semiconductor – DDR2 Registered SDRAM MODULE 240pin Registered Module based on 256Mb F-die 72-bit ECC

256MB, 512MB Registered DIMMs
DDR2 SDRAM
Electrical Characteristics & AC Timing for DDR2-667/533/400 SDRAM
(0 °C < T_CASE < 95 °C; V_DDQ = 1.8V + 0.1V; V_DD = 1.8V + 0.1V)
Refresh Parameters by Device Density
Parameter
Refresh to active/Refresh command time
tRFC
Average periodic refresh interval
tREFI
Symbol
0 °C ≤ T_CASE ≤ 85°C
85 °C < T_CASE ≤ 95°C
256Mb
75
7.8
3.9
512Mb
105
7.8
3.9
1Gb
127.5
7.8
3.9
2Gb 4Gb Units
195 tbd
ns
7.8 7.8
µs
3.9 3.9
µs
Speed Bins and CL, tRCD, tRP, tRC and tRAS for Corresponding Bin
Speed
Bin (CL - tRCD - tRP)
Parameter
tCK, CL=3
tCK, CL=4
tCK, CL=5
tRCD
tRP
tRC
tRAS
DDR2-667(E6)
5-5-5
min
max
5
8
3.75
8
3
8
15
15
54
39
70000
DDR2-533(D5)
4-4-4
min
max
5
8
3.75
8
-
-
15
15
55
40
70000
DDR2-400(CC)
3-3-3
min
max
5
8
5
8
-
-
15
15
55
40
70000
Units
ns
ns
ns
ns
ns
ns
ns
Timing Parameters by Speed Grade
(Refer to notes for informations related to this table at the bottom)
Parameter
Symbol
DDR2-667
min
max
DQ output access time from CK/CK
tAC
-450
+450
DQS output access time from CK/CK
tDQSCK
-400
+400
CK high-level width
tCH
0.45
0.55
CK low-level width
tCL
0.45
0.55
CK half period
tHP
min(tCL, tCH)
x
Clock cycle time, CL=x
tCK
3000
8000
DQ and DM input hold time
tDH
175
x
DQ and DM input setup time
tDS
50
x
Control & Address input pulse width for each
input
tIPW
0.6
x
DQ and DM input pulse width for each input tDIPW
0.35
x
Data-out high-impedance time from CK/CK
tHZ
x
tAC max
DQS low-impedance time from CK/CK
tLZ(DQS)
tAC min
tAC max
DQ low-impedance time from CK/CK
tLZ(DQ)
2*tAC min
tAC max
DQS-DQ skew for DQS and associated DQ
signals
tDQSQ
x
250
DQ hold skew factor
tQHS
x
350
DQ/DQS output hold time from DQS
tQH
tHP - tQHS
x
Write command to first DQS latching transition tDQSS
WL-0.25
WL+0.25
DQS input high pulse width
tDQSH
0.35
x
DDR2-533
min
max
-500
+500
-450
+450
0.45
0.55
0.45
0.55
min(tCL, tCH)
x
3750
8000
225
x
100
x
DDR2-400
min
max
-600
+600
-500
+500
0.45
0.55
0.45
0.55
min(tCL, tCH)
x
5000
8000
275
x
150
x
0.6
x
0.6
x
0.35
x
tAC min
2* tACmin
x
tAC max
tAC max
tAC max
0.35
x
tAC min
2* tACmin
x
tAC max
tAC max
tAC max
x
300
x
350
x
tHP - tQHS
WL-0.25
0.35
400
x
WL+0.25
x
x
tHP - tQHS
WL-0.25
0.35
450
x
WL+0.25
x
Units Notes
ps
ps
tCK
tCK
ps
ps
ps
ps
tCK
tCK
ps
ps
ps
ps
ps
ps
tCK
tCK
Rev. 1.3 Aug. 2005