Altera Stratix - Differential SSTL-2 Termination

Altera Corporation 5–49
July 2005 Stratix Device Handbook, Volume 2
High-Speed Differential I/O Interfaces in Stratix Devices
Figure 5–37. Differential HSTL Class II Termination
Differential SSTL-2 Termination
The SSTL-2 Class I and II I/O standards require a 1.25-V V
REF
and a
1.25-V V
TT
. Figures 5–37 and 5–38 show the device with differential
termination for SSTL-2 Class I and II I/O standard.
Figure 5–38. Differential SSTL-2 Class I Termination
Differential
Transmitter
Differential
Receiver
Z
0
= 50 Ω
50 Ω 50 Ω
Z
0
= 50 Ω
V
TT
= 0.75 V V
TT
= 0.75 V
50 Ω 50 Ω
V
TT
= 0.75 V V
TT
= 0.75 V
Differential
Transmitter
Differential
Receiver
Z
0
= 50 Ω
50 Ω 50 Ω
Z
0
= 50 Ω
V
TT
= 1.25 V V
TT
= 1.25 V
25 Ω
25 Ω