HYB18T512400AC5 Datasheet, PDF (85/96 Pages) Infineon Technologies AG – 512-Mbit Double-Data-Rate-Two SDRAM

HYB18T512[400/800/160]A[C/F]–[3.7/5]
512-Mbit Double-Data-Rate-Two SDRAM
Reference Loads, Setup & Hold Timing Definition and Slew Rate Derating
DQS
DQS
DQS
t _DS t _DH
tDS tDH
Figure 69 Data, Setup and Hold Time Diagram
Differential Input
Waveform
Single-ended Input
Waveform
V _REF
V_DDQ
V_IH(ac) min
V_IH(dc) min
V_REF
V_IL(dc) max
V_IL(ac) max
V_SS
8.3.3 Slew Rate Definition for Input and Data Setup and Hold Times
Setup (t_DS) nominal slew rate for a rising signal is
defined as the slew rate between the last crossing of
V_REF(dc) and the first crossing of V_IH(ac)min. Setup (t_DS)
nominal slew rate for a falling signal is defined as the
slew rate between the last crossing of V_REF(dc) and the
first crossing of V_IL(ac)max. If the actual signal is always
earlier than the nominal slew rate line between shaded
‘V_REF(dc) to ac region’, use nominal slew rate for derating
value.(Figure 70)
Hold (t_DH) nominal slew rate for a rising signal is defined
as the slew rate between the last crossing of V_IL(dc)max
and the first crossing of V_REF(dc). Hold (t_DH) nominal slew
rate for a falling signal is defined as the slew rate
between the last crossing of V_IH(dc)min and the first
crossing of V_REF(dc). If the actual signal is always later
than the nominal slew rate line between shaded ‘dc
level to V_REF(dc) region’, use nominal slew rate for
derating value. (Figure 72)
If the actual signal is later than the nominal slew rate
line anywhere between shaded ‘V_REF(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.
(Figure 71)
If the actual signal is earlier than the nominal slew rate
line anywhere between shaded ‘dc to V_REF(dc) region’,
the slew rate of a tangent line to the actual signal from
the dc level to V_REF(dc) level is used for derating
value.(Figure 73)
Data Sheet
85
Rev. 1.13, 2004-05
09112003-SDM9-IQ3P