Supplying Voltage For Arduino Mega2560?

Other Hardware General Electronics
1

from the datasheet Arduino mega2560:

  • Input Voltage 7-12V(recommended)
  • DC Current per I/O Pin 40 mA
  • DC Current for 3.3V Pin 50 mA

but i can't find what the maximum current for power supply?

does arduino have input current limit, when I use the supplying voltage(power supply) via the power jack ..

if it has, how much maximum current that can be received by arduino?

2

The input voltage is the input to the regulator on the mega board. The current is what you can source or sink from an individual pin.

For the chip itself look at the absolute maximum ratings in the data sheet. However without anything being drawn from the output pins it draws about 30mA.

if it has, how much maximum current that can be received by arduino?

That is a very odd way of describing things. Are you asking what current rating the power supply has to be? If you have a 12V 2A power supply the current drawn by any circuit will be exactly the same as if you had a 12V 10A power supply.

The power and ground pins can take 200mA each and there are 4 on the chip so the total current drawn by pins attached to the chip can not exceed 800mA. This is a bit false because other considerations come into play first, like the individual pin groupings. In the data sheet it says:-

  1. Although each I/O port can sink more than the test conditions (20mA at VCC = 5V, 10mA at VCC = 3V) under steady state conditions (non-transient), the following must be observed:-
    ATmega1281/2561:
    1.)The sum of all IOL, for ports A0-A7, G2, C4-C7 should not exceed 100 mA.
    2.)The sum of all IOL, for ports C0-C3, G0-G1, D0-D7 should not exceed 100 mA.
    3.)The sum of all IOL, for ports G3-G5, B0-B7, E0-E7 should not exceed 100 mA.
    4.)The sum of all IOL, for ports F0-F7 should not exceed 100 mA.
    ATmega640/1280/2560:
    1.)The sum of all IOL, for ports J0-J7, A0-A7, G2 should not exceed 200 mA.
    2.)The sum of all IOL, for ports C0-C7, G0-G1, D0-D7, L0-L7 should not exceed 200 mA.
    3.)The sum of all IOL, for ports G3-G4, B0-B7, H0-B7 should not exceed 200 mA.
    4.)The sum of all IOL, for ports E0-E7, G5 should not exceed 100 mA.
    5.)The sum of all IOL, for ports F0-F7, K0-K7 should not exceed 100 mA.
    If IOL exceeds the test condition, VOL may exceed the related specification. Pins are not guaranteed to sink current greater than the listed test condition.
3

yes i understand if the total current drawn by pins attached to the chip can not exceed 800mA..
but my question is, is it okay if i use 9V 4A power supply.. will it harm the arduino? is there maximum current value from power supply?

4

, is it okay if i use 9V 4A power supply.

Yes

will it harm the arduino?

No.

s there maximum current value from power supply?

Yes, in this case the maximum current from the power supply is 4A. The Arduino however will take nowhere near that.

Please read:- http://www.thebox.myzen.co.uk/Tutorial/Power_Supplies.html

5

ok.. Thank you.. :wink:

6

YoungZy:

  • DC Current for 3.3V Pin 50 mA

Nothing to do with your questions or the answers.

But this is wrong in the datasheet.
The Mega has an onboard 3.3volt regulator that is capable of supplying 150mA, not 50mA.
Leo..