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Figure 29: Tangent Line for tIH
Tangent
line
DC to Vref
region
tIH
tIS
Vss
VddQ
Vih(dc) MIN
Vref(dc)
Vil(ac) MAX
Vil(dc) MAX
Vih(ac) MIN
DC to Vref
region
Tangent
line
tIH
CK
CK#
Hold slew rate
falling signal
Δ
TF
Δ
TR
Tangent line (Vih[dc] MIN - Vref[dc])
Δ
TF
=
Nominal
line
Hold slew rate
rising signal
Tangent line (Vref[dc] - Vil[dc] MAX)
Δ
TR
=
Nominal
line
Table 30: DDR2-400/533 tDS, tDH Derating Values with Differential Strobe
All units are shown in picoseconds
DQ
Slew
Rate
(V/ns)
DQS, DQS# Differential Slew Rate
4.0 V/ns
3.0 V/ns
2.0 V/ns
1.8 V/ns
1.6 V/ns
1.4 V/ns
1.2 V/ns
1.0 V/ns
0.8 V/ns
Δ
tDS
Δ
tDH
Δ
tDS
Δ
tDH
Δ
tDS
Δ
tDH
Δ
tDS
Δ
tDH
Δ
tDS
Δ
tDH
Δ
tDS
Δ
tDH
Δ
tDS
Δ
tDH
Δ
tDS
Δ
tDH
Δ
tDS
Δ
tDH
2.0
125
45
125
45
125
45
–
1.5
83
21
83
21
83
21
95
33
–
1.0
0
12
24
–
0.9
–
–11
–14
–11
–14
1
–2
13
10
25
22
–
0.8
–
–25
–31
–13
–19
–1
–7
11
5
23
17
–
0.7
–
–31
–42
–19
–30
–7
–18
5
–6
17
6
–
0.6
–
–43
–59
–31
–47
–19
–35
–7
–23
5
–11
0.5
–
–74
–89
–62
–77
–50
–65
–38
–53
0.4
–
–127 –140 –115 –128 –103 –116
Notes: 1. For all input signals, the total tDS and tDH required is calculated by adding the data
512Mb: x4, x8, x16 DDR2 SDRAM
Input Slew Rate Derating
PDF: 09005aef82f1e6e2
Rev. M 9/08 EN
65
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2004 Micron Technology, Inc. All rights reserved.