Datasheet

Rev. 1.2 / Jul. 2013 18
AC and DC Input Levels for Single-Ended Signals
DDR3 SDRAM will support two Vih/Vil AC levels for DDR3-800 and DDR3-1066 as specified in the table
below. DDR3 SDRAM will also support corresponding tDS values (Table 43 and Table 51 in “DDR3 Device
Operation”) as well as derating tables in Table 46 of “DDR3 Device Operation” depending on Vih/Vil AC lev-
els.
Notes:
1. Vref = VrefDQ (DC).
2. Refer to "Overshoot and Undershoot Specifications" on page 30.
3. The ac peak noise on V
Ref
may not allow V
Ref
to deviate from V
RefDQ(DC)
by more than +/-1% VDD (for reference:
approx. +/- 15 mV).
4. For reference: approx. VDD/2 +/- 15 mV.
5. VIH(dc) is used as a simplified symbol for VIH.DQ(DC100)
6. VIL(dc) is used as a simplified symbol for VIL.DQ(DC100)
7. VIH(ac) is used as simplified symbol for VIH.DQ(AC175), VIH.DQ(AC150), and VIH.DQ(AC135); VIH.DQ(AC175)
value is used when Vref + 0.175V is referenced, VIH.DQ(AC150) value is used when Vref + 0.150V is referenced,
and VIH.DQ(AC135) value is used when Vref + 0.135V is referenced.
8. VIL(ac) is used as simplified symbol for VIL.DQ(AC175), VIL.DQ(AC150), and VIL.DQ(AC135); VIL.DQ(AC175)
value is used when Vref - 0.175V is referenced, VIL.DQ(AC150) value is used when Vref - 0.150V is referenced,
and VIL.DQ(AC135) value is used when Vref - 0.135V is referenced.
Single Ended AC and DC Input Levels for DQ and DM
Symbol Parameter
DDR3-800/1066 DDR3-1333/1600 DDR3-1866
Unit Notes
Min Max Min Max Min Max
VIH.DQ(DC100) DC input logic high Vref + 0.100 VDD Vref + 0.100 VDD Vref + 0.100 VDD V 1, 5
VIL.DQ(DC100) DC input logic low VSS Vref - 0.100 VSS Vref - 0.100 VSS Vref - 0.100 V 1, 6
VIH.DQ(AC175) AC input logic high Vref + 0.175 Note2 - - - - V 1, 2, 7
VIL.DQ(AC175) AC input logic low Note2 Vref - 0.175 - - - - V 1, 2, 8
VIH.DQ(AC150) AC Input logic high Vref + 0.150 Note2 Vref + 0.150 Note2 Vref + 0.150 Note2 V 1, 2, 7
VIL.DQ(AC150) AC input logic low Note2 Vref - 0.150 Note2 Vref - 0.150 Note2 Vref - 0.150 V 1, 2, 8
VIH.CA(AC135) AC input logic high - - - - Vref + 0.135 Note2 mV 1, 2, 7
VIL.CA(AC135) AC input logic low - - - - Note2 Vref - 0.135 mV 1, 2, 8
V
RefDQ(DC
)
Reference Voltage
for DQ, DM inputs
0.49 * VDD 0.51 * VDD 0.49 * VDD 0.51 * VDD 0.49 * VDD 0.51 * VDD V 3, 4