AMS73CAG01808RA
To guarantee tight setup and hold times as well as output skew parameters with respect to clock and strobe,
each cross point voltage of differential input signals (CK, CK and DQS, DQS) must meet the requirements in
below table. The differential input cross point voltage VIX is measured from the actual cross point of true and
complement signal to the mid level between of VDD and VSS.
VDD
CK, DQS
VIX
VDD/2
VIX
VIX
CK, DQS
VSS
VIX Definition
Cross point voltage for differential input signals ( CK, DQS )
Symbol
VIX
Parameter
Min.
-150
-175
-150
Max.
150
175
150
Units
mV
Notes
Differential Input Cross Point Voltage relative to VDD/2 for CK, CK
Differential Input Cross Point Voltage relative to VDD/2 for DQS, DQS
mV
1
VIX
mV
NOTE :1. Extended range for VIX is only allowed for clock and if single-ended clock input signals CKand CK are mono-
tonic, have a single-ended swing VSEL / VSEH of at least VDD/2 +/- 250 mV, and the differential slew rate of
CK-CK is larger than 3 V/ ns. Refer to the table of Cross point voltage for differential input signals (CK, DQS)
for VSEL and VSEH standard values.
Differential input slew rate definition
Measured
Description
Defined by
From
To
VIHdiff (min) - VILdiff (max)
Delta TRdiff
Differential input slew rate for rising edge ( CK-CK and DQS-DQS )
Differential input slew rate for falling edge ( CK-CK and DQS-DQS )
VILdiff (max) VIHdiff (min)
VIHdiff (min) VILdiff (max)
VIHdiff (min) - VILdiff (max)
Delta TFdiff
NOTE : The differential signal (i.e. CK - CK and DQS - DQS) must be linear between these thresholds.
V
IHdiffmin
0
V
ILdiffmax
delta TFdiff
delta TRdiff
Differential Input Slew Rate definition for DQS,
DQS, and CK, CK
AMS73CAG01808RA Rev. 1.0 December 2010
19
AMS [ Advanced Monolithic Systems Ltd ]
