Arduino Mega 2560 +5v supply current.

Hi, I know this is a really basic question, and I have searched this forum, but I just can't find any where that tells me how much current I can draw from the +5v onboard regulator.

My current project uses several shields and breakout boards that require a 5v supply currently being drawn from the motherboard, I'm concerned that I may be approaching the limits, but am not sure what the limits are.

The mainpage for the mega conveniently informs me that the 3.3v onboard regulator can supply 50mA, but provides no similar data for the 5v regulator.


If you power from USB you have 500 mA to play with. If you power from Vin or the power jack you can draw up to 1 A from the regulator.

Note: The more power you draw through the regulator the more important it is to keep the input voltage close to 7V. If you use a 7V supply and draw 1 A the regulator has to dissipate 2W ((7V-5V)*1A). At 12V it has to dissipate 7W ((12V-5V)*1A).

Thanks John,

Reassuring to know that I'm actually no-where here the max!

BTW, where should I have gone to get those figures, I couldn't find them anywhere!

So when someone needs power supply for his arduino , the important think is the voltage . For example for my uno i found power supplies with 12V and 7V , with 2A or 5A , the Ampere has nothing to do with frying the board , only voltage can make damage , is that right ?

As i understood if someone uses a lot of shields and other stuff that powers from arduino 5V and GND pins , he has to keep this low 2W ((7V-5V)*1A) , is that correct ? thanks !