![](http://datasheet.mmic.net.cn/380000/EDD2516AETA-7A-E_datasheet_16755484/EDD2516AETA-7A-E_8.png)
EDD2508AETA, EDD2516AETA
Data Sheet E0859E50 (Ver. 5.0)
8
AC Characteristics (TA = 0
°
C to +70
°
C, VDD, VDDQ = 2.6V ± 0.1V, VSS, VSSQ = 0V) [DDR400]
-5B
-5C
Parameter
Symbol
min.
max.
min.
max.
Unit
Notes
Clock cycle time
tCK
5
8
5
8
ns
10
CK high-level width
tCH
0.45
0.55
0.45
0.55
tCK
CK low-level width
tCL
0.45
0.55
0.45
0.55
tCK
CK half period
tHP
min
(tCH, tCL)
—
min
(tCH, tCL)
—
tCK
DQ output access time from CK, /CK
tAC
–0.7
0.7
–0.7
0.7
ns
2, 11
DQS output access time from CK, /CK
tDQSCK
–0.55
0.55
–0.55
0.55
ns
2, 11
DQS to DQ skew
tDQSQ
—
0.4
—
0.4
ns
3
DQ/DQS output hold time from DQS
tQH
tHP – tQHS —
tHP – tQHS —
ns
Data hold skew factor
tQHS
—
0.5
—
0.5
ns
Data-out high-impedance time
from CK, /CK
Data-out low-impedance time
from CK, /CK
tHZ
—
0.7
—
0.7
ns
5, 11
tLZ
–0.7
0.7
–0.7
0.7
ns
6, 11
Read preamble
tRPRE
0.9
1.1
0.9
1.1
tCK
Read postamble
tRPST
0.4
0.6
0.4
0.6
tCK
DQ and DM input setup time
tDS
0.4
—
0.4
—
ns
8
DQ and DM input hold time
tDH
0.4
—
0.4
—
ns
8
DQ and DM input pulse width
tDIPW
1.75
—
1.75
—
ns
7
Write preamble setup time
tWPRES
0
—
0
—
ns
Write preamble
tWPRE
0.25
—
0.25
—
tCK
Write postamble
tWPST
0.4
0.6
0.4
0.6
tCK
9
Write command to first DQS latching transition tDQSS
0.72
1.28
0.72
1.28
tCK
DQS falling edge to CK setup time
tDSS
0.2
—
0.2
—
tCK
DQS falling edge hold time from CK
tDSH
0.2
—
0.2
—
tCK
DQS input high pulse width
tDQSH
0.35
—
0.35
—
tCK
DQS input low pulse width
tDQSL
0.35
—
0.35
—
tCK
Address and control input setup time
tIS
0.6
—
0.6
—
ns
8
Address and control input hold time
tIH
0.6
—
0.6
—
ns
8
Address and control input pulse width
tIPW
2.2
—
2.2
—
ns
7
Mode register set command cycle time
tMRD
2
—
2
—
tCK
Active to Precharge command period
tRAS
40
120000
40
120000
ns
Active to Active/Auto-refresh command period tRC
55
—
60
—
ns
Auto-refresh to Active/Auto-refresh command
period
tRFC
70
—
70
—
ns
Active to Read/Write delay
tRCD
15
—
18
—
ns
Precharge to active command period
tRP
15
—
18
—
ns
Active to Autoprecharge delay
tRAP
tRCD min. —
tRCD min. —
ns
Active to active command period
tRRD
10
—
10
—
ns
Write recovery time
tWR
15
—
15
—
ns
Auto precharge write recovery and precharge
time
tDAL
(tWR/tCK)+
(tRP/tCK)
—
(tWR/tCK)+
(tRP/tCK)
—
tCK
13
Internal write to Read command delay
tWTR
2
—
2
—
tCK
Average periodic refresh interval
tREF
—
7.8
—
7.8
μs