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K4B2G1646C-HCF8000 Datasheet, PDF (52/64 Pages) Samsung semiconductor – 2Gb C-die DDR3 SDRAM Only x16 96FBGA with Lead-Free & Halogen-Free (RoHS compliant)
K4B2G1646C
datasheet
Rev. 1.11
DDR3 SDRAM
14.3 Address/Command Setup, Hold and Derating :
For all input signals the total tIS (setup time) and tIH (hold time) required is calculated by adding the data sheet tIS(base) and tIH(base) value (see
Table 51) to the ∆tIS and ∆tIH derating value (see Table 52) respectively.
Example: tIS (total setup time) = tIS(base) + ∆tIS Setup (tIS) nominal slew rate for a rising signal is defined as the slew rate between the last crossing of
VREF(DC) and the first crossing of VIH(AC)min. Setup (tIS) nominal slew rate for a falling signal is defined as the slew rate between the last crossing of
VREF(DC) and the first crossing of VIL(AC)max. If the actual signal is always earlier than the nominal slew rate line between shaded ’VREF(DC) to ac
region’, use nominal slew rate for derating value (see Figure 21). If the actual signal is later than the nominal slew rate line anywhere between shaded
’VREF(DC) to ac region’, the slew rate of a tangent line to the actual signal from the ac level to dc level is used for derating value (see Figure 23).
Hold (tIH) nominal slew rate for a rising signal is defined as the slew rate between the last crossing of VIL(DC)max and the first crossing of VREF(DC).
Hold (tIH) nominal slew rate for a falling signal is defined as the slew rate between the last crossing of VIH(DC)min and the first crossing of VREF(DC). If
the actual signal is always later than the nominal slew rate line between shaded ’dc to VREF(DC) region’, use nominal slew rate for derating value (see
Figure 22). If the actual signal is earlier than the nominal slew rate line anywhere between shaded ’dc to VREF(DC) region’, the slew rate of a tangent line
to the actual signal from the dc level to VREF(DC) level is used for derating value (see Figure 24).
For a valid transition the input signal has to remain above/below VIH/IL(AC) for some time tVAC (see Table 56).
Although for slow slew rates the total setup time might be negative (i.e. a valid input signal will not have reached VIH/IL(AC) at the time of the rising clock
transition) a valid input signal is still required to complete the transition and reach VIH/IL(AC).
For slew rates in between the values listed in Table 52, the derating values may obtained by linear interpolation.
These values are typically not subject to production test. They are verified by design and characterization.
[ Table 51 ] ADD/CMD Setup and Hold Base-Values for 1V/ns
[ps]
DDR3-800
DDR3-1066
DDR3-1333
DDR3-1600
DDR3-1866
DDR3-2133
reference
tIS(base) AC175
200
125
65
45
-
-
VIH/L(AC)
tIS(base) AC150
350
275
190
170
-
-
VIH/L(AC)
tIS(base)-AC135
-
-
-
-
65
60
VIH/L(AC)
tIS(base)-AC125
-
-
-
-
150
135
VIH/L(AC)
tIH(base)-DC100
275
200
140
120
100
95
VIH/L(DC)
NOTE :
1. AC/DC referenced for 1V/ns Address/Command slew rate and 2 V/ns differential CK-Ck slew rate
2. The tIS(base)-AC150 specifications are adjusted from the tIS(base) AC175 specification by adding an additional 125ps for DDR3-800/1066 or 100ps for
DDR3-1333/1600 of derating to accommodate for the lower alternate threshold of 150mV and another 25ps to account for the earlier reference point
[(175mV-150mV)/1 V/ns]
3. The tIS(base) AC125 specifications are adjusted from the tIS(base) AC135 specification by adding an additional 75ps for DDR3-1866 and 65ps for DDR3-2133 to accommo-
date for the lower alternate threshold of 125mV and another 10ps to account for the earlier reference point [(135mV-125mV)/1V/ns].
[ Table 52 ] Derating values DDR3-800/1066/1333/1600 tIS/tIH-AC/DC based AC175 Threshold
∆tIS, ∆tIH Derating [ps] AC/DC based
Alternate AC175 Threshold -> VIH(AC) = VREF(DC) + 175mV, VIL(AC) = VREF(DC) - 175mV
CLK,CLK Differential Slew Rate
4.0 V/ns
3.0 V/ns
2.0 V/ns
1.8 V/ns
1.6 V/ns
1.4V/ns
1.2V/ns
∆tIS ∆tIH ∆tIS ∆tIH ∆tIS ∆tIH ∆tIS ∆tIH ∆tIS ∆tIH ∆tIS ∆tIH ∆tIS ∆tIH
2.0
88
50
88
50
88
50
96
58 104 66 112 74 120 84
1.5
59
34
59
34
59
34
67
42
75
50
83
58
91
68
1.0
0
0
0
0
0
0
8
CMD/
ADD 0.9
-2
-4
-2
-4
-2
-4
6
8
16
16
24
24
32
34
4
14
12
22
20
30
30
Slew 0.8
-6
-10
-6
-10
-6
-10
2
-2
10
6
18
14
26
24
rate 0.7
-11
-16
-11
-16
-11
-16
-3
-8
5
V/ns
0
13
8
21
18
0.6 -17 -26 -17 -26 -17 -26
-9
-18
-1
-10
7
-2
15
8
0.5 -35 -40 -35 -40 -35 -40 -27 -32 -19 -24 -11 -16
-2
-6
0.4 -62 -60 -62 -60 -62 -60 -54 -52 -46 -44 -38 -36 -30 -26
1.0V/ns
∆tIS ∆tIH
128 100
99
84
40
50
38
46
34
40
29
34
23
24
5
10
-22 -10
- 52 -