K4B1G0446G Datasheet, PDF (16/64 Pages) Samsung semiconductor – 1Gb G-die DDR3 SDRAM

K4B1G0446G
K4B1G0846G
datasheet
Rev. 1.01
DDR3 SDRAM
8.4 Differential Input Cross Point Voltage
To guarantee tight setup and hold times as well as output skew parameters with respect to clock and strobe, each cross point voltage of differential input
signals (CK, CK and DQS, DQS) must meet the requirements in below table. The differential input cross point voltage V_IX is measured from the actual
cross point of true and complement signal to the mid level between of V_DD and V_SS.
V_DD
CK, DQS
V_IX
V_IX
V_IX
V_DD/2
CK, DQS
V_SS
Figure 4. VIX Definition
[ Table 12 ] Cross point voltage for differential input signals (CK, DQS)
Symbol
Parameter
DDR3-800/1066/1333/1600/1866
Min
Max
Unit NOTE
V_IX
Differential Input Cross Point Voltage relative to V_DD/2 for CK,CK
-150
-175
150
mV
175
mV
1
V_IX
Differential Input Cross Point Voltage relative to V_DD/2 for DQS,DQS
-150
150
mV
NOTE :
1. Extended range for V_IX is only allowed for clock and if single-ended clock input signals CKand CK are monotonic, have a single-ended swing V_SEL / V_SEH of at least V_DD/2
±250 mV, and the differential slew rate of CK-CK is larger than 3 V/ ns. Refer to Table 11 on page 15 for V_SEL and V_SEH standard values.
2. The relation between V_IX Min/Max and V_SEL/V_SEH should satisfy following.
(V_DD/2) + V_IX(Min) - V_SEL ≥ 25mV
V_SEH - ((V_DD/2) + V_IX(Max)) ≥ 25mV
8.5 Slew rate definition for Differential Input Signals
See 14.3 “Address/Command Setup, Hold and Derating :” on page 48 for single-ended slew rate definitions for address and command signals.
See 14.4 “Data Setup, Hold and Slew Rate Derating :” on page 54 for single-ended slew rate definitions for data signals.
8.6 Slew rate definitions for Differential Input Signals
Input slew rate for differential signals (CK, CK and DQS, DQS) are defined and measured as shown in Table 13 and Figure 5.
[ Table 13 ] Differential input slew rate definition
Description
Differential input slew rate for rising edge (CK-CK and DQS-DQS)
Measured
From
To
V_ILdiffmax
V_IHdiffmin
Differential input slew rate for falling edge (CK-CK and DQS-DQS)
V_IHdiffmin
NOTE :
The differential signal (i.e. CK - CK and DQS - DQS) must be linear between these thresholds.
V_ILdiffmax
Defined by
V_IHdiffmin - V_ILdiffmax
Delta TRdiff
V_IHdiffmin - V_ILdiffmax
Delta TFdiff
V_IHdiffmin
0
V_ILdiffmax
delta TFdiff
delta TRdiff
Figure 5. Differential Input Slew Rate definition for DQS, DQS, and CK, CK
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