10

Integrated Silicon Solution, Inc. — www.issi.com

Rev. 00A

6/4/2013

IS43/46DR81280C, IS43/46DR16640C

Differential input AC Logic Level

Symbol

Parameter

Min.

Max.

Units Notes

VID (ac)

ac differential input voltage

0.5

VDDQ

V

1,3

VIX (ac)

ac differential crosspoint voltage 0.5 x VDDQ - 0.175

0.5 x VDDQ + 0.175

V

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 and

VCP is the complementary input signal (such as CK or DQS). The minimum value is equal to VIH(AC) - VIL(AC).

2. The typical value of VIX(AC) is expected to be about 0.5 x 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.

3. Refer to Overshoot/undershoot specifications for Vpeak value: maximum peak amplitude allowed for overshoot and undershoot.

Differential signal levels

Crossing point

Differential AC Output Parameters

Symbol Parameter

Min.

Max.

Units Notes

VOX (ac) ac differential crosspoint voltage

0.5 x VDDQ - 0.125

0.5 x VDDQ + 0.125

V

1

Note:

1. The typical value of VOX(AC) is expected to be about 0.5 x 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.