Xilinx Spartan-3 User Manual page 46

R
2.5V and 1.2V regulators. Similarly, the 3.3V regulator feeds all the V
inputs to the FPGA's I/O banks and powers most of the components on the board.
The 2.5V regulator supplies power to the FPGA's V
voltage input supplies power to Digital Clock Managers (DCMs) within the FPGA and
supplies some of the I/O structures. In specific, all of the FPGA's dedicated configuration
pins, such as DONE, PROG_B, CCLK, and the FPGA's JTAG pins, are powered by V
The FPGA configuration interface on the board is powered by 3.3V. Consequently, the 2.5V
supply has a current shunt resistor to prevent reverse current.
Finally, a 1.2V regulator supplies power to the FPGA's V
power the FPGA's core logic.
The board uses three discrete regulators to generate the necessary voltages. However,
various power supply vendors are developing integrated solutions specifically for
Spartan-3 FPGAs.
Figure A-3
Figure A-6
46
provides a detailed schematic of the various voltage regulators. Similarly,
shows the power decoupling capacitors.
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Chapter 12: Power Distribution
voltage supply
CCO
supply inputs. The V
CCAUX
voltage inputs, which
CCINT
Spartan-3 Starter Kit Board User Guide
UG130 (v1.1) May 13, 2005
CCAUX
.
CCAUX