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K4T51043QE Datasheet, PDF (14/45 Pages) Samsung semiconductor – 512Mb E-die DDR2 SDRAM Specification
K4T51043QE
K4T51083QE
K4T51163QE
DDR2 SDRAM
7.6 Differential input AC logic Level
Symbol
Parameter
Min.
Max.
Units
Notes
VID(AC)
AC differential input voltage
0.5
VDDQ + 0.6
V
1
VIX(AC)
AC differential cross point voltage
0.5 * VDDQ - 0.175
0.5 * VDDQ + 0.175
V
2
Note :
1. VID(AC) specifies the input differential voltage |VTR -VCP | required for switching, where VTR is the true input signal (such as CK, DQS, LDQS or UDQS)
and VCP is the complementary input signal (such as CK, DQS, LDQS or UDQS). The minimum value is equal to V IH (AC) - V IL(AC).
2. The typical value of VIX(AC) is expected to be about 0.5 * VDDQ of the transmitting device and VIX(AC) is expected to track variations in VDDQ . VIX(AC)
indicates the voltage at which differential input signals must cross.
VTR
VCP
VDDQ
VID
Crossing point
VIX or VOX
VSSQ
7.7 Differential AC output parameters
< Differential signal levels >
Symbol
Parameter
Min.
Max.
Units
Note
VOX(AC) AC differential cross point voltage
0.5 * VDDQ - 0.125
0.5 * VDDQ + 0.125
V
1
Note :
1. The typical value of VOX(AC) is expected to be about 0.5 * VDDQ of the transmitting device and VOX(AC) is expected to track variations in VDDQ .
VOX(AC) indicates the voltage at which differential output signals must cross.
8.0 ODT DC electrical characteristics
PARAMETER/CONDITION
Rtt effective impedance value for EMRS(A6,A2)=0,1; 75 ohm
Rtt effective impedance value for EMRS(A6,A2)=1,0; 150 ohm
Rtt effective impedance value for EMRS(A6,A2)=1,1; 50 ohm
Deviation of VM with respect to VDDQ/2
Note :
1. Test condition for Rtt measurements
SYMBOL
Rtt1(eff)
Rtt2(eff)
Rtt3(eff)
delta VM
MIN NOM MAX UNITS NOTES
60
75
90
ohm
1
120
150
180
ohm
1
40
50
60
ohm
1
-6
+6
%
1
Measurement Definition for Rtt(eff) : Apply VIH (ac) and VIL (ac) to test pin separately, then measure current I(VIH (ac)) and I( VIL (ac)) respectively.
VIH (ac), VIL (ac), and VDDQ values defined in SSTL_18
VIH (ac) - VIL (ac)
Rtt(eff) =
I(VIH (ac)) - I(VIL (ac))
delta VM =
2 x Vm
- 1 x 100%
VDDQ
Measurement Definition for VM: Measure voltage (VM) at test pin (midpoint) with no load.
14 of 45
Rev. 1.8 July 2007