Hstl Class Ii (1.8V) - Xilinx Virtex-5 FPGA User Manual

Table 6-22
Table 6-22: Differential HSTL Class I (1.8V) DC Voltage Specifications
Notes:
1. Common mode voltage: V
2. Crossover point: V

HSTL Class II (1.8V)

Figure 6-56
Class II (1.8V) with unidirectional termination.
X-Ref Target - Figure 6-56
External Termination
IOB
HSTL_II_18
DCI
2R
VRP
HSTL_II_DCI_18
2R
VRN
Figure 6-56: HSTL Class II (1.8V) with Unidirectional Termination
Virtex-5 FPGA User Guide
UG190 (v5.0) June 19, 2009
lists the differential HSTL Class I (1.8V) DC voltage specifications.
V
CCO
V
TT
V (DC)
IN
V (DC)
DIFF
(1)
V (DC)
CM
V (AC)
DIFF
(2)
V (Crossover)
X
CM
where V
X
shows a sample circuit illustrating a valid termination technique for HSTL
V = 0.9V
TT
R P = Z 0 = 50Ω
IOB
V = 1.8V
CCO
= 2Z 0 = 100Ω
= 2Z 0 = 100Ω
www.xilinx.com
Specific Guidelines for I/O Supported Standards
Min
1.7
–
–0.30
0.20
0.83
0.40
0.83
= V – ((V – V )/2)
P P N
– V = 0 (AC coupled)
P N
V = 0.9V
TT
IOB
R P = Z 0 = 50Ω
Z 0
V
IOB
V = 1.8V
CCO
2R
VRP
Z 0
2R
VRN
Typ
1.8
× 0.5
V
CCO
– V
CCO
– V
CCO
–
– V
CCO
–
HSTL_II_18
+
–
= 0.9V
REF
= 2Z 0 = 100Ω
HSTL_II_DCI_18
+
–
V = 0.9V
REF
= 2Z 0 = 100Ω
ug190_6_53_030306
Max
1.9
–
+ 0.30
+ 0.60
1.08
+ 0.60
1.08
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