Maximum current for USB port Arduino Mega 2560?

What is maximum current for USB port Arduino Mega 2560 ?

Because I want to power my arduino with USB port.....not with jack 2.1mm

Can I use USB port arduino to power the arduino?

Yes, of course. How much current do you anticipate your project taking and how much current can the PC USB port provide ?

Note that what you must not do is to use a pin on the Mega to supply more than a few milliamps

Your post was MOVED to its current location as it is more suitable.

Can I use 5V/2A usb adapter ?
Or 5V/1A usb adapter ?


Thanks for help me answer my question✨

The MEGA 2560, like the UNO, has a 500 mA polyfuse in the USB-VCC line. It will never draw more than 500 mA from the USB connector.

So that's mean.....
Its ok for me to use 5V 2A adapter USB ??

Because you say the USB can't draw more than 500ma

right ?


It sounds like you need to do some reading on Ohms Law. Just because the USB can supply 2A it does not mean that the Arduino will use 2A

There's a hint here.

There are limits on how much current each 8-bit port on the 2560 is rated to provide to the corresponding output pins as well as a sensible limit of much less than 40 mA per individual pin. You really should not be expecting to provide significant current to multiple pins; that would indicate something wrong with your overall concept.

So the total current the 2560 drives to outputs is already limited to less than 500 mA. What you do not do is to expect to provide current to the USB port and expect to draw current from the "5V" pin; that is only marginally more practical than attempting to power it via "Vin" or the "barrel jack" which you have apparently discovered is indeed a most terrible idea.

You have a 5 V power supply for your overall project. Connect it to the "5V" pin and everything else that require 5 V (and needless to say, connect all the grounds). Just disconnect the "5V" pin whenever you plug the USB into a PC for programming or monitoring. :+1:

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