Table 11: AC Operating Specifications and Conditions (Continued)
Not all speed grades listed may be supported for this device; refer to the title page for speeds supported; Notes: 1–5 apply to the entire table;
VDDQ = +1.8V ±0.1V, VDD = +1.8V ±0.1V
AC Characteristics
-187E
-25E
-25
-3E
-3
-37E
-5E
Parameter
Symbol Min Max Min Max Min Max Min Max Min Max Min Max Min Max Units Notes
Internal READ-to-
PRECHARGE delay
tRTP
7.5
2
7.5
2
7.5
2
7.5
2
7.5
2
7.5
2
7.5
2
ns
18, 37,
39
–
–
–
–
–
–
–
–
–
–
–
–
–
–
CAS#-to-CAS#
delay
tCCD
tCK
18
Write recovery time
tWR
tDAL
15
tWR +
tRP
15
tWR +
tRP
15
tWR +
tRP
15
tWR +
tRP
15
tWR +
tRP
15
tWR +
tRP
15
tWR +
tRP
ns
ns
18, 37
40
–
–
–
–
–
–
–
–
–
–
–
–
–
–
Write AP recovery
+ precharge time
Internal WRITE-to-
READ delay
tWTR
tMRD
tRFC
7.5
7.5
7.5
7.5
7.5
7.5
10
ns
tCK
ns
18, 37
18
–
–
–
–
–
–
–
–
–
–
–
–
–
–
LOAD MODE cycle
time
2
2
2
2
2
2
2
REFRESH- 256Mb
75
75
75
75
75
75
75
18, 41
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
to-
ACTIVATE
or to
-REFRESH
interval
512Mb
1Gb
105
105
105
105
105
105
105
127.5
197.5
127.5
197.5
127.5
197.5
127.5
197.5
127.5
197.5
127.5
197.5
127.5
197.5
2Gb
Average periodic
refresh
(commercial)
tREFI
tREFIIT
tREFIAT
tDELAY
7.8
3.9
3.9
7.8
3.9
3.9
7.8
3.9
3.9
7.8
3.9
3.9
7.8
3.9
3.9
7.8
3.9
3.9
7.8
3.9
3.9
µs
µs
µs
ns
18, 41
18, 41
18, 41
42
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
Average periodic
refresh
(industrial)
Average periodic
refresh
(automotive)
CKE LOW to CK,
CK# uncertainty
MIN limit = tIS + tCK + tIH
MAX limit = n/a
MICRON [ MICRON TECHNOLOGY ]
