Data Sheet
HY[B/E]18M1G16[0/1]BF
1-Gbit DDR Mobile-RAM
19) The maximum limit for this parameter is not a device limit. The device operates with a greater value for this parameter, but system
performance (bus turnaround) will degrade accordingly.
20) A low level on DQS may be maintained during High-Z states (DQS drivers disabled) by adding a weak pull-down element in the system. It
is recommended to turn off the weak pull-down element during read and write bursts (DQS drivers enabled).
21) These parameters account for the number of clock cycles and depend on the operating frequency, as follows:
no. of clock cycles = specified delay / clock period; round to the next higher integer.
22) tDAL = (tWR / tCK) + (tRP / tCK): for each of the terms above, if not already an integer, round to the next higher integer.
23) A maximum of eight AUTOREFRESH commands can be posted to the DDR Mobile-RAM device, meaning that the maximum absolute
interval between any Refresh command and the next Refresh command is 8 * tREFI
.
FIGURE 40
Measurement with Reference Load
)ꢉ/
:
ꢀ ꢁ ꢊꢀ /HMS
ꢃꢀ P&
TABLE 24
Output Slew Rate Characteristics
Parameter
Typical Range
Minimum
Maximum
Unit
Note
1)2)
Pull-up and Pull-down Slew Rate
(Full Drive Buffer)
TBD
0.7
0.3
0.7
2.5
1.0
1.4
V/ns
1)2)
1)3)
Pull-up and Pull-down Slew Rate
(Half Drive Buffer)
TBD
-
V/ns
-
Output Slew Rate Matching Ratio
(Pull-up to Pull-down)
1) Output slew rate is measured between VILD(DC) and VIHD(AC) (rising) or VIHD(DC) and VILD(AC) (falling).
2) The parameter is measured using a 20pF capacitive load connected to VSSQ
.
3) The ratio of the pull-up slew rate to the pull-down slew rate is specified for the same temperature and voltage, over the entire temperature
and voltage range. For a given output, it represents the maximum difference between pull-up and pull-down drivers due to process
variation.
TABLE 25
AC Overshoot / Undershoot Specification
Parameter
Maximum
Unit
Note
Maximum peak amplitude allowed for overshoot
Maximum peak amplitude allowed for undershoot
Maximum overshoot area above VDD
0.9
0.9
3.0
3.0
V
–
–
–
–
V
V-ns
V-ns
Maximum undershoot area below VSS
Rev.1.0, 2007-03
57
10242006-Y557-TZXW
QIMONDA [ QIMONDA AG ]
