K4B2G1646C-HCF8000 Datasheet, PDF(13/64 Page) Samsung semiconductor – 2Gb C-die DDR3 SDRAM Only x16 96FBGA with Lead-Free & Halogen-Free (RoHS compliant)

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K4B2G1646C-HCF8000 Datasheet, PDF (13/64 Pages) Samsung semiconductor – 2Gb C-die DDR3 SDRAM Only x16 96FBGA with Lead-Free & Halogen-Free (RoHS compliant)

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K4B2G1646C

datasheet

8.3 AC & DC Logic Input Levels for Differential Signals

8.3.1 Differential signals definition

VIH.DIFF.AC.MIN

tDVAC

VIH.DIFF.MIN

Rev. 1.11

DDR3 SDRAM

0.0

VIL.DIFF.MAX

VIL.DIFF.AC.MAX

half cycle

tDVAC

time

Figure 2. Definition of differential ac-swing and "time above ac level" tDVAC

8.3.2 Differential swing requirement for clock (CK - CK) and strobe (DQS - DQS)

[ Table 9 ] Differential AC & DC Input Levels

Symbol

Parameter

DDR3-800/1066/1333/1600/1866/2133

min

max

unit

NOTE

VIHdiff

differential input high

+0.2

NOTE 3

VILdiff

differential input low

NOTE 3

-0.2

VIHdiff(AC)

differential input high ac

2 x (VIH(AC) - VREF)

NOTE 3

VILdiff(AC)

differential input low ac

NOTE 3

2 x (VIL(AC) - VREF)

NOTE :

1. Used to define a differential signal slew-rate.

2. for CK - CK use VIH/VIL(AC) of ADD/CMD and VREFCA; for DQS - DQS, DQSL - DQSL, DQSU - DQSU use VIH/VIL(AC) of DQs and VREFDQ; if a reduced ac-high or ac-low

level is used for a signal group, then the reduced level applies also here.

3. These values are not defined, however they single-ended signals CK, CK, DQS, DQS, DQSL, DQSL, DQSU, DQSU need to be within the respective limits (VIH(DC) max,

VIL(DC)min) for single-ended signals as well as the limitations for overshoot and undershoot. Refer to "overshoot and Undershoot Specification"

[ Table 10 ] Allowed time before ringback (tDVAC) for CK - CK and DQS - DQS

Slew Rate [V/ns]

tDVAC [ps] @ |VIH/Ldiff(AC)|

= 350mV

min

max

tDVAC [ps] @ |VIH/Ldiff(AC)|

= 300mV

min

max

> 4.0

175

4.0

170

3.0

167

2.0

163

1.8

162

1.6

161

1.4

159

1.2

155

1.0

150

< 1.0

150

tDVAC [ps] @ |VIH/Ldiff(AC)|

= 270mV

min

max

TBD

tDVAC [ps] @ |VIH/Ldiff(AC)|

= 250mV

min

max

TBD

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