Feed 5v to the 5v pin on Arduino

Hi, I just started a project and it seems that my project needed more amps than the on board voltage regulator on Arduino Mega 2560 R3 can supply, I already tried feeding 9v 1a via the dc 2.1mm on the arduino but the voltage regulator overheats and it stalled so I am thinking a way to feed a 5v to arduino 5v pin , is it safe to do that ?

and also it is safe to build a protoshield with dc connector 2.1 mm feed with 5v , and that dc connector is directly connected to 5v pin ? is it recommended to add capacitor or any filtering circuit ?

thank you

Where is all the current going? Is it all thru Mega IO pins, or in parallel via the 5V header pin?
The onboard regulator is only good for 800mA, and then only from a 7.5V source maybe, and overheating will still be a concern. The 800mA must be spread over the IO ports, see section 29 or 03 of the data sheet showing the port limitations.
Can feed 5V into the 5V header pin, connect a diode from 5V (anode) to Vin (cathode) to avoid reverse driving the regulator.
Can put 5V into the barrel jack - need to jumper over the reverse polarity diode (or lose 0.7V) and the 5V regulator (which will drop some more voltage too).

Hi, Thanks for replying

The current is going to parallel via 5v header pin and I plan to take a protoshield and put dc barrel jack on it, from the dc barrel jack on the protoshield, I will connect it to the 5v pin and gnd, and I will feed 5v to the dc barrel jack on the protoshield. My current project has too many shields I think, I have official ethernet shield r3, seeedstudio nfc v2.0,seed studio xbee shield, and the basic lcd.

Thank you

sorry to ask again, what diode is recommended ? is 1N4007 enough ? I am worried for its only 1A rating

Thank you

That'd be plenty, you just need to get some input voltage.
See page 11 - 1n4002 is used

Also rated at 1A

Thank you, sorry for asking again, would it look like this ?

thank you

Yes it would. Very nice.

Ok, thank you very much for your advice :slight_smile:
btw where is that rep+ button ?

Use the karma button.