Voltage; Powering Up The Board; Measuring Current Consumption On The At91Sam7A2 - Atmel AT91SAM7A2-EK User Manual

2.4

Voltage

2.5 Powering Up the
Board
2.6 Measuring
Current
Consumption on
the AT91SAM7A2
2-2
6115B–ATARM–10-May-05
DC power is supplied to the board via the 2.1 mm connector (J1) shown in Figure 2-2.
The polarity of the power supply is not critical. The minimum voltage required is 7V. The
supply must be isolated from ground. The 0 volts of the on-board regulated supplies can
be connected to ground via any one of the 4 test points, TP1 to TP4.
Figure 2-2. 2.1mm Connector
The board has a voltage regulator providing +3.3V and another providing +5V. These
regulators allow the input voltage to be from 7V to 12V.
Figure 2-3. Powering Up the Board
Switch the
power on
The red LED marked
"DS1" lights up
The board is designed to generate the entire power supply of the AT91SAM7A2 device.
The PCB power tracks to the ARM7 core, the I/O and the analog cells are independent.
This feature enables measurement of the current consumption of the different major
parts of the AT91SAM7A2 device.
Table 2-1. Current Consumption Measurement Procedure
Block to Measure
Core
Analog Cells
I/O Cells
Positive (+) or
Negative(-)
No
Yes
End
Strap to Unsolder
E1
E2
E3
AT91SAM7A2-EK Evaluation Board User Guide
Switch off, check the
fuse and the power
supply connections
Action
Connect an ammeter in place
of the strap