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HYMP164U64CP6-C4 Datasheet, PDF (13/29 Pages) Hynix Semiconductor – 240pin DDR2 SDRAM Unbuffered DIMMs
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1240pin DDR2 SDRAM Unbuffered DIMMs
Differential Input AC logic Level
Symbol
Parameter
Min.
Max.
Units Note
VID (ac) ac differential input voltage
0.5
VDDQ + 0.6
V
1
VIX (ac) ac differential cross point voltage
0.5 * VDDQ - 0.175 0.5 * VDDQ + 0.175
V
2
1. VIN(DC) specifies the allowable DC execution of each input of differential pair such as CK, CK, DQS, DQS, LDQS,
LDQS, UDQS and UDQS.
2. VID(DC) specifies the input differential voltage |VTR -VCP | required for switching, where VTR is the true input (such as
CK, DQS, LDQS or UDQS) level and VCP is the complementary input (such as CK, DQS, LDQS or UDQS) level. The
minimum value is equal to VIH(DC) - VIL(DC).
VTR
VCP
VDDQ
VID
Crossing point
VIX or VOX
VSSQ
< Differential signal levels >
Note:
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) - VIL(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 whitch differential input signals must cross.
DIFFERENTIAL AC OUTPUT PARAMETERS
Symbol
VOX (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 whitch differential output signals must cross.
Rev. 0.6 / Jul. 2008
13
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