EP1S40F780C7 Datasheet, PDF (862/864 Pages) Altera Corporation – Stratix Device Handbook, Volume 1

Board Layout
Figure 14–18 shows how to use regulators to generate 1.5-V and 2.5-V
power supplies if the system needs two power supply systems. One
regulator is used for each power supply.
Figure 14–18. Two Regulator Solution for Systems that Require 5.0-V, 2.5-V & 1.5-V Supply Levels
PCB
5.0 V
Regulator
1.5 V
1.5-V
Device
Regulator
2.5 V
2.5-V
Device
Altera
Cyclone
FPGA
Figure 14–19 shows how to use a single regulator to generate two
different power supplies (1.5-V and 2.5-V). The use of a single regulator
to generate 1.5-V and 2.5-V supplies from the 5.0-V power supply can
minimize the board size and thus save cost.
Figure 14–19. Single Regulator Solution for Systems that Require 5.0-V, 2.5-V & 1.5-V Supply Levels
PCB
5.0 V
Regulator
1.5 V
2.5 V
1.5-V
Device
Altera
Cyclone
FPGA
2.5-V
Device
14–22
Stratix Device Handbook, Volume 2
Altera Corporation
January 2005