- 15 -
datasheet
DDR3L SDRAM
Rev. 1.0
Unbuffered DIMM
11.3 AC and DC Logic Input Levels for Differential Signals
11.3.1 Differential Signals Definition
Figure 3. Definition of differential ac-swing and "time above ac level" tDVAC
11.3.2 Differential Swing Requirement for Clock (CK - CK) and Strobe (DQS - DQS)
NOTE
:
1. Used to define a differential signal slew-rate.
2. for CK - CK use V
IH
/V
IL
(AC) of ADD/CMD and V
REFCA
; for DQS - DQS use V
IH
/V
IL
(AC) of DQs and V
REFDQ
; if a reduced ac-high or ac-low level is used for a signal group,
then the reduced level applies also here.
3. These values are not defined, however they single-ended signals CK, CK, DQS, DQS need to be within the respective limits (V
IH
(DC) max, V
IL
(DC)min) for single-ended sig-
nals as well as the limitations for overshoot and undershoot. Refer to "overshoot and Undersheet Specification"
Symbol
Parameter
DDR3-800/1066/1333/1600
unit
NOTE
1.35V
1.5V
min
max
min
max
V
IHdiff
differential input high
+0.18
NOTE 3
+0.20
NOTE 3
V
1
V
ILdiff
differential input low
NOTE 3
-0.18
NOTE 3
-0.20
V
1
V
IHdiff
(AC)
differential input high ac 2 x (V
IH
(AC) - V
REF
)
NOTE 3
2 x (V
IH
(AC) - V
REF
)
NOTE 3
V
2
V
ILdiff
(AC)
differential input low ac
NOTE 3
2 x (V
IL
(AC) - V
REF
)
NOTE 3
2 x (V
IL
(AC) - V
REF
)
V
2
0.0
tDVAC
V
IH
.DIFF.MIN
half cycle
Di
ffe
rent
ial
Inp
ut V
olt
ag
e (i.
e. DQS-DQS
, C
K
-C
K
)
time
tDVAC
V
IH
.DIFF.AC.MIN
V
IL
.DIFF.MAX
V
IL
.DIFF.AC.MAX