K4T51043Q Datasheet, PDF (13/28 Pages) Samsung semiconductor – 512Mb B-die DDR2 SDRAM

512Mb B-die DDR2 SDRAM
DDR2 SDRAM
Differential input AC logic Level
Symbol
VID(AC)
VIX(AC)
Parameter
AC differential input voltage
AC differential cross point voltage
Min.
0.5
0.5 * VDDQ - 0.175
Max.
VDDQ + 0.6
0.5 * VDDQ + 0.175
Units
V
V
Notes
1
2
Notes:
1. VID(AC) specifies the input differential voltage |VTR -VCP | required for switching, where VTR is the true input signal (such as CK, DQS, LDQS or UDQS)
and VCP is the complementary input signal (such as CK, DQS, LDQS or UDQS). The minimum value is equal to V IH (AC) - V IL(AC).
2. The typical value of VIX(AC) is expected to be about 0.5 * VDDQ of the transmitting device and VIX(AC) is expected to track variations in VDDQ .
VIX(AC) indicates the voltage at which differential input signals must cross.
V_DDQ
V_TR
V_CP
V_ID
Crossing point
V_{IX or} V_OX
V_SSQ
< Differential signal levels >
Differential AC output parameters
Symbol
V_OX(AC)
Parameter
AC differential cross point voltage
Min.
0.5 * VDDQ - 0.125
Max.
0.5 * VDDQ + 0.125
Units
V
Note
1
Note :
1. The typical value of VOX(AC) is expected to be about 0.5 * VDDQ of the transmitting device and VOX(AC) is expected to track variations in VDDQ .
VOX(AC) indicates the voltage at which differential output signals must cross.
Page 13 of 28
Rev. 1.5 July 2005