Measuring Power Across Voltage Supply Jumpers - Xilinx Spartan-3A User Manual

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Measuring Power Across Voltage Supply Jumpers

All regulator output supplies have an associated series jumper, as indicated in
and shown in
multimeter.
For example, to measure the Suspend mode current on the FPGA's V
supplies, follow these steps.
•
•
Table 17-2: FPGA Supply Rails and Associated Voltage Supply Jumper
•
•
Spartan-3A/3AN Starter Kit Board User Guide
UG334 (v1.0) May 28, 2007
Figure 17-1. This allows for simple and easy current monitoring using just a
Caution!
The Suspend feature must first be enabled in the actual FPGA application. All the
example designs initially shipped with the board have the Suspend feature enabled.
Disconnect power to the board.
Remove the series jumper associated with the supply to be measured, shown in
Table 17-2. Locate jumper indicated in
FPGA Supply Rail
V
CCINT
V
CCAUX
Connect a digital multimeter across the jumper, as highlighted in
resulting current is negative, simply reverse the connections to the jumpers.
Measured Current Set Current Range
(mA)
Figure 17-2: Measuring Current (Power) Using a Multimeter
Set the meter to measure DC Amperes. Initially set the meter to the Ampere range. If
appropriate, switch to a lower range (for example, 200 mA) after initially measuring
current in the Ampere range.
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Measuring Power Across Voltage Supply Jumpers
Figure 17-1.
Associated Voltage
Supply Jumper
J9
J11
VCCAUX (3.3V)
(200 mA DC)
(Jumper J11)
Table 17-1
or V
CCAUX CCINT
Default Voltage
1.2V
3.3V
Figure 17-2. If the
VCCINT (1.2V)
(Jumper J9)
UG330_c17_02_032207
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