4 differential input cross point voltage, Differential input cross point voltage, Datasheet – Samsung M391B5773DH0 User Manual

Page 18: Ddr3l sdram, Unbuffered dimm

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datasheet

DDR3L SDRAM

Rev. 1.0

Unbuffered DIMM

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 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

.

Figure 5. V

IX

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 V

IX

is only allowed for clock and if single-ended clock input signals CK and 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.

Symbol

Parameter

DDR3L-800/1066/1333/1600

Unit

NOTE

Min

Max

V

IX

Differential Input Cross Point Voltage relative to V

DD

/2 for CK,CK

-150

150

mV

1

V

IX

Differential Input Cross Point Voltage relative to V

DD

/2 for DQS,DQS

-150

150

mV

Symbol

Parameter

DDR3-800/1066/1333/1600

Unit

NOTE

Min

Max

V

IX

Differential Input Cross Point Voltage relative to V

DD

/2 for CK,CK

-150

150

mV

-175

175

mV

1

V

IX

Differential Input Cross Point Voltage relative to V

DD

/2 for DQS,DQS

-150

150

mV

V

DD

CK, DQS

V

DD

/2

CK, DQS

V

SS

V

IX

V

IX

V

IX

VSEH

VSEL

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