Stratix II and Stratix II GX I/O Standards Support
Figure 4–10. Differential SSTL-2 Class I Termination
VTT = 1.25 V
VTT = 1.25 V
Differential
Transmitter
Differential
Receiver
50 Ω
50 Ω
25 Ω
25 Ω
Z
= 50 Ω
0
Z
= 50 Ω
0
Figure 4–11. Differential SSTL-2 Class II Termination
VTT = 1.25 V
VTT = 1.25 V
VTT = 1.25 V
VTT = 1.25 V
Differential
Transmitter
Differential
Receiver
50 Ω
25 Ω
50 Ω
50 Ω
50 Ω
Z
= 50 Ω
= 50 Ω
0
25 Ω
Z
0
Differential SSTL-18 Class I and Differential SSTL-18 Class II
The 1.8-V differential SSTL-18 standard is formulated under JEDEC
Standard, JESD8-15: Stub Series Terminated Logic for 1.8-V (SSTL_18).
The differential SSTL-18 I/O standard is a 1.8-V standard used for
applications such as high-speed DDR2 SDRAM interfaces. This standard
supports differential signals in systems using the SSTL-18 standard and
supplements the SSTL-18 standard for differential clocks.
1
Stratix II and Stratix II GX devices support both input and
output levels operation.
4–12
Stratix II Device Handbook, Volume 2
Altera Corporation
January 2008
ALTERA [ ALTERA CORPORATION ]
