DC and Switching Characteristics
Table 4–28. SSTL-18 Class I & II Differential Specifications
Symbol
Parameter
Conditions
Minimum
1.71
Typical
Maximum
Unit
V
VCCIO
Output supply voltage
DC differential input voltage
1.8
1.89
VSWING
(DC)
0.25
V
VX (AC)
AC differential input cross
point voltage
(VCCIO/2) – 0.175
0.5
(VCCIO/2) + 0.175
V
V
VSWING
(AC)
AC differential input voltage
VISO
Input clock signal offset
voltage
0.5 VCCIO
200
V
ΔVISO
Input clock signal offset
voltage variation
mV
V
VOX (AC) AC differential cross point
(VCCIO/2) – 0.125
(VCCIO/2) + 0.125
voltage
Table 4–29. SSTL-2 Class I Specifications
Symbol
VCCIO
VTT
Parameter
Conditions
Minimum
2.375
Typical
Maximum Unit
Output supply voltage
Termination voltage
2.5
2.625
VREF + 0.04
1.313
V
V
V
V
V
V
V
V
V
VREF – 0.04
1.188
VREF
1.25
VREF
Reference voltage
V
V
V
V
IH (DC)
IL (DC)
IH (AC)
IL (AC)
High-level DC input voltage
Low-level DC input voltage
High-level AC input voltage
Low-level AC input voltage
High-level output voltage
Low-level output voltage
VREF + 0.18
–0.3
3.0
VREF – 0.18
VREF + 0.35
VREF – 0.35
VTT – 0.57
VOH
VOL
IOH = –8.1 mA (1)
IOL = 8.1 mA (1)
VTT + 0.57
Note to Table 4–29:
(1) This specification is supported across all the programmable drive settings available for this I/O standard as shown
in the Arria GX Architecture chapter in volume 1 of the Arria GX Device Handbook.
Table 4–30. SSTL-2 Class II Specifications (Part 1 of 2)
Symbol
VCCIO
VTT
Parameter
Output supply voltage
Termination voltage
Reference voltage
Conditions
Minimum
2.375
Typical
2.5
Maximum Unit
2.625
VREF + 0.04
1.313
V
V
V
VREF – 0.04
1.188
VREF
1.25
VREF
Altera Corporation
May 2008
4–27
Arria GX Device Handbook, Volume 1
ALTERA [ ALTERA CORPORATION ]
