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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 = +1.5–1.9V, VDD = +1.5–1.9V
AC Characteristics
-25E
-25
-3E
-3
-37E
Units
Notes
Parameter
Symbol
Min
Max
Min
Max
Min
Max
Min
Max
Min
Max
Data
Strobe-Out
DQS output access time
from CK/CK#
tDQSCK
–350
+350
–350
+350
–400
+400
–400
+400
–450
+450
ps
DQS read preamble
tRPRE
MIN = 0.9 × tCK
MAX = 1.1 × tCK
tCK
DQS read postamble
tRPST
MIN = 0.4 × tCK
MAX = 0.6 × tCK
tCK
CK/CK# to DQS
Low-Z
tLZ1
MIN = tAC (MIN)
MAX = tAC (MAX)
ps
Data
Strobe-In
DQS rising edge to CK
rising edge
tDQSS
MIN = –0.25 × tCK
MAX = +0.25 × tCK
tCK
DQS input-high pulse
width
tDQSH
MIN = 0.35 × tCK
MAX = n/a
tCK
DQS input-low pulse
width
tDQSL
MIN = 0.35 × tCK
MAX = n/a
tCK
DQS falling to CK
rising: setup time
tDSS
MIN = 0.2 × tCK
MAX = n/a
tCK
DQS falling from CK
rising: hold time
tDSH
MIN = 0.2 × tCK
MAX = n/a
tCK
Write preamble setup
time
tWPRES
MIN = 0
MAX = n/a
ps
DQS write preamble
tWPRE
MIN = 0.35 × tCK
MAX = n/a
tCK
DQS write postamble
tWPST
MIN = 0.4 × tCK
MAX = 0.6 × tCK
tCK
WRITE command to first
DQS transition
–
MIN = WL - tDQSS
MAX = WL + tDQSS
tCK
1Gb:
x4,
x8,
x16
1.55V
DDR2
SDRAM
AC
Timing
Operating
Specifications
PDF:
09005aef82b91d01
1GbDDR2_1_55V.PDF
Rev.
A
5/09
EN
30
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Technology,
Inc.
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2009
Micron
Technology,
Inc.
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reserved.