Output Electrical Characteristics and Operating Conditions
Table 17: Differential AC Output Parameters
Parameter
Symbol
Min
Max
Units
Notes
AC differential cross-point voltage
VOX(AC)
0.50 × VDDQ - 125
0.50 × VDDQ + 125
mV
AC differential voltage swing
Vswing
1.0
–
mV
Note: 1. The typical value of VOX(AC) is expected to be about 0.5 × VDDQ of the transmitting de-
vice and VOX(AC) is expected to track variations in VDDQ. VOX(AC) indicates the voltage at
which differential output signals must cross.
Figure 14: Differential Output Signal Levels
Crossing point
VOX
VSSQ
Vswing
VDDQ
VTR
VCP
Table 18: Output DC Current Drive
Parameter
Symbol
Value
Units
Notes
Output MIN source DC current
IOH
–13.4
mA
Output MIN sink DC current
IOL
13.4
mA
Notes: 1. For IOH(DC); VDDQ = 1.7V, VOUT = 1,420mV. (VOUT - VDDQ)/IOH must be less than 21Ω for
values of VOUT between VDDQ and VDDQ - 280mV.
2. For IOL(DC); VDDQ = 1.7V, VOUT = 280mV. VOUT/IOL must be less than 21Ω for values of VOUT
between 0V and 280mV.
3. The DC value of VREF applied to the receiving device is set to VTT.
4. The values of IOH(DC) and IOL(DC) are based on the conditions given in Notes 1 and 2. They
are used to test device drive current capability to ensure VIH,min plus a noise margin and
VIL,max minus a noise margin are delivered to an SSTL_18 receiver. The actual current val-
ues are derived by shifting the desired driver operating point (see output IV curves)
along a
21Ω load line to define a convenient driver current for measurement.
1Gb: x4, x8, x16 DDR2 SDRAM
Output Electrical Characteristics and Operating Conditions
PDF: 09005aef821ae8bf
1GbDDR2.pdf – Rev. S 10/09 EN
47
Micron Technology, Inc. reserves the right to change products or specifications without notice.
2004 Micron Technology, Inc. All rights reserved.