Xilinx virtex-5 fpga

266 www.xilinx.com Virtex-5 FPGA User Guide
UG190 (v5.0) June 19, 2009
Chapter 6: SelectIO Resources
Figure 6-57 shows a sample circuit illustrating a valid termination technique for HSTL
Class II (1.8V) with bidirectional termination.
X-Ref Target - Figure 6-57
Figure 6-57: HSTL Class II (1.8V) with Bidirectional Termination
Z
0
IOB
IOB
HSTL_II_18
HSTL_II_18
ug190_6_54_030306
V
TT
= 0.9V
R
P
= Z
0
= 50Ω
V
TT
= 0.9V
R
P
= Z
0
= 50Ω
Z
0
IOB
IOB
HSTL_II_DCI_18
HSTL_II_DCI_18
V
CCO
= 1.8V
2R
VRP
= 2Z
0
= 100Ω
2R
VRN
= 2Z
0
= 100Ω
V
REF
= 0.9V
V
REF
= 0.9V
+
–
V
REF
= 0.9V
+
–
External Termination
DCI
V
CCO
= 1.8V
2R
VRP
= 2Z
0
= 100Ω
2R
VRN
= 2Z
0
= 100Ω
V
REF
= 0.9V