4.3 Power Supply

The USB port powers the board. It contains two LDO regulators, one to generate 3.3V for the on-board debugger and an adjustable LDO regulator for the target AVR64EA48 microcontroller and its peripherals. The voltage from a USB connector can vary between 4.4V and 5.25V (according to the USB specification) and will limit the maximum voltage supplied to the target. The figure below shows the entire power supply system on AVR64EA48 Curiosity Nano.