Samsung M391B5273DH0, M391B5773DH0 Differential Input Cross Point Voltage, CK, DQS Vsel

11.3.4 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 VIX is measured from the actual cross point of true and complement signal to the mid level between of VDD and VSS.

VDD

Figure 5. VIX Definition

[ Table 7 ] Cross point voltage for differential input signals (CK, DQS) : 1.35V

NOTE :

1.The relationbetween Vix Min/Max and VSEL/VSEH should satisfy following. (VDD/2) + Vix(Min) - VSEL ≥ 25mV

VSEH - ((VDD/2) + Vix(Max)) ≥ 25mV

[ Table 8 ] Cross point voltage for differential input signals (CK, DQS) : 1.5V

NOTE :

1.Extended range for VIX is only allowed for clock and if single-ended clock input signals CK and CK are monotonic, have a single-ended swing VSEL / VSEH of at least VDD/2 ±250 mV, and the differential slew rate of CK-CK is larger than 3 V/ ns.

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