K4C561638C-TCD4000 Datasheet, PDF (13/42 Pages) Samsung semiconductor – 256Mb Network-DRAM

K4C5608/1638C
256Mb Network-DRAM
AC Test Conditions
Symbol
V_IH(min)
V_IL (max)
V_REF
V_TT
V_SWING
V_R
V_ID(AC)
SLEW
V_OTR
Parameter
Input high voltage (minimum)
Input low voltage (maximum)
Input reference voltage
Termination voltage
Input signal peak to peak swing
Differential clock input reference level
Input differential voltage
Input signal minimum slew rate
Output timing measurement reference voltage
VddQ
V_SWING
V_IH min_(AC)
V_REF
V_IL max_(AC)
Vss
∆T
∆T
Value
V_REF + 0.35
V_REF - 0.35
VddQ/2
V_REF
1.0
V_X(AC)
1.5
1.0
VddQ/2
Measurement Point
Output
Units
V
V
V
V
V
V
V
V/ns
V
V_TT
Notes
R_T=50Ω
Z=50Ω
CL=30pF
V_REF
=0.5*VddQ
Output Load Circuit(SSTL_2)
Slew=(V_IHmin_(AC) - V_ILmax_(AC))/∆T
Notes : 1. Transition times are measured between V_IH min_(DC) and V_IL max_(DC).
Transition (rise and fall) of input signals have a fixed slope.
2. If the result of nominal calculation with regard to t_CK contains more than
one decimal place, the result is rounded up to the nearest decimal place.
(i.e., t_DQSS = 0.75*t_CK, t_CK = 5ns, 0.75*5ns = 3.75ns is rounded up to 3.8ns.)
3. These parameters are measured from the differential clock (CK and CK) AC cross point.
4. These parameters are measured from signal transition point of DQS crossing V_REF level.
5. The t_REFI (MAX.) applies to equally distributed refresh method.
The t_REFI (MIN.) applies to both burst refresh method and distributed refresh method.
In such case, the average interval of eight consecutive Auto-Refresh commands has to be more than 400ns always. In
other words, the number of Auto- Refresh cycles which can be performed within 3.2us (8X400ns) is to 8 times in the
maximum.
6. Low Impedance State is speified at VddQ/2± 0.2V from steady state.
7. High Impedance State is specified where output buffer is no longer driven.
8. These parameters depend on the clock jitter. These parameters are measured at stable clock.
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REV. 0.7 Aug. 2003