DC & Switching Characteristics
Table 6–19. GTL+ I/O Specifications
Symbol
Parameter
Termination voltage
Reference voltage
Conditions
Minimum Typical Maximum Units
VTT
1.35
1.5
1.0
1.65
1.12
V
V
V
V
VREF
VIH
0.88
High-level input voltage
Low-level input voltage
VREF + 0.1
VIL
VREF
0.1
–
VOL
Low-level output voltage
IOL = 36 mA (1)
0.65
V
Table 6–20. GTL I/O Specifications
Symbol
Parameter
Termination voltage
Reference voltage
High-level input voltage
Conditions
Minimum Typical Maximum Units
VTT
1.14
0.74
1.2
0.8
1.26
0.86
V
V
V
VREF
VIH
VREF
+
0.05
VIL
Low-level input voltage
Low-level output voltage
VREF
0.05
–
V
V
VOL
IOL = 40 mA (1)
0.4
Table 6–21. SSTL-18 Class I Specifications
Symbol
Parameter
Conditions
Minimum
Typical
1.8
Maximum
1.95
Units
VCCIO
Output supply voltage
Reference voltage
1.65
V
V
V
V
VREF
VTT
0.8
0.9
1.0
Termination voltage
High-level DC input voltage
VREF – 0.04
VREF
VREF + 0.04
VIH(DC)
VREF
+
0.125
VIL(DC)
VIH(AC)
VIL(AC)
VOH
Low-level DC input voltage
High-level AC input voltage
Low-level AC input voltage
High-level output voltage
Low-level output voltage
VREF
0.125
–
V
V
V
V
V
VREF
0.275
+
VREF
0.275
–
IOH = –6.7 mA
(1)
VTT + 0.475
VOL
IOL = 6.7 mA (1)
VTT – 0.475
Altera Corporation
August 2005
6–17
Stratix GX Device Handbook, Volume 1
ALTERA [ ALTERA CORPORATION ]
