M1AFS250-FGG256I Actel Corporation, M1AFS250-FGG256I Datasheet - Page 163

• Manufacturer Part Number: M1AFS250-FGG256I
• Description: Actel Fusion Family Of Mixed Signal Fpgas
• Manufacturer: Actel Corporation

Temporary overshoots are allowed according to
Figure 2-101 • Solution 1
Solution 2
The board-level design must ensure that the reflected waveform at the pad does not exceed limits
provided in
This scheme will also work for a 3.3 V PCI/PCI-X configuration, but the internal diode should not be used
for clamping, and the voltage must be limited by the external resistors and Zener, as shown in
102. Relying on the diode clamping would create an excessive pad DC voltage of 3.3 V + 0.7 V = 4 V.
Figure 2-102 • Solution 2
Table 3-4 on page
5.5 V
3-4. This is a long-term reliability requirement.
Zener 3.3 V diode, LVCMOS 3.3 V I/Os
5.5 V
Rext1
Zener
3.3 V
Off-Chip
Requires one board resistor, one
Off-Chip
Rext1
Rext2
Requires two board resistors,
Solution 2
R e v i s i o n 1
LVCMOS 3.3 V I/Os
Solution 1
Table 3-4 on page
On-Chip
On-Chip
Fusion I/O Input
Fusion I/O Input
Actel Fusion Family of Mixed Signal FPGAs
3-4.
3.3 V
3.3 V
Figure 2-
2- 147