AVR32918

3

32159A-AVR-01/11

Figure 3-2. Functional overview of the Atmel UC3-A3 XPLAINED kit.

3.1 Preprogrammed firmware

The Atmel AT32UC3A3256 on the Atmel UC3-A3 XPLAINED kit is preprogrammed

with a USB bootloader and a default firmware. The preprogrammed firmware in the

AT32UC3A3256 is a simple demonstration of the QTouch button and QTouch slider.

3.2 Power supply

The kit needs an external power supply that can deliver 5V and up to 500mA. The

actual current requirement for the board is much less than 500mA but in order to be

able to power possible expansion boards this margin is needed.

The power can be applied to the board either via the USB connector or on pin 10 on

the header J3. The USB connector is the preferred input because then it is possible to

connect expansion boards on top of the J3 header.

The 5V is regulated down to 3.3V with an on board LDO regulator, which provides

power to the entire board. Expansion top boards that require 5V will get this from the

header J3 pin 10.

3.3 Measuring the AT32UC3A3256 power consumption

As part of an evaluation of the AT32UC3A3256, it can be of interest to measure its

power consumption. The two-pin header with a jumper mounted on it is the only