Chapter 17: Voltage Supplies - Xilinx Spartan-3A User Manual

R
Voltage Supplies
The voltage supplies are located in the upper left corner of the board, as shown in
Figure
The Spartan-3A/3AN Starter Kit board requires a 5.0V DC voltage input, typically
supplied by the AC wall adapter included with the kit. However, there is also a provision
to connect the board directly to a 5.0V DC supply using through-hole mounting solder
pads.
The AC wall adapter must be a regulated 5.0V DC supply, as supplied with the kit. Some
components and interfaces on the board, such as the LCD character display and the PS/2
port are powered directly from the 5.0V supply rail.
The 5.0V input voltage is then converted to the other supply voltages required by the
board components, as summarized in
space-efficient and cost-effective National Semiconductor LP3906 Quad-Output voltage
Spartan-3A/3AN Starter Kit Board User Guide
UG334 (v1.0) May 28, 2007
17-1.
AC wall adapter connector (5V DC)
Power control
ON
switch
OFF
Supply to FPGA
I/O Bank 3, J13
DDR2 SDRAM
J12
Supply to FPGA
I/O Banks 0, 1, 2 J10
Figure 17-1: Spartan-3A/3AN Starter Kit Board Voltage Supplies
Caution!
Connect either the AC wall adapter OR use the through-hole mounting pads, but not
both.
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Through-hole option to power the board (5V DC)
J42 J41
REG2_SCL
LP3906
(IC18)
REG2_SDA
J40
J11
REG1_SCL
LP3906
(IC19)
REG1_SDA
J9
Table 17-1. All non-5V voltages are supplied by two
Chapter 17
Power-on status LED
External I 2 C control input
option to IC18
Supply to FPGA
core (VCCAUX)
External I 2 C control input
option to IC19
Supply to FPGA
core (VCCINT)
UG330_cx_01_021507
137