Hot chip next to the ardunio mega power jack

Development Boards Arduino
1

So I’ve been doing a lot with my arduino lately and I noticed just now that the chip right next to the barrel connector of my mega is really hot.

So I did some testing to see whats making it hot.

It gets hot when it’s powered by an external source - 12v in from a computer power supply.

I checked the specs at http://arduino.cc/en/Main/ArduinoBoardMega and it says the recommended input voltage is 7-12v so it should be good, but that chip is hot to the touch. I’m running the power into the Vin pin and not the barrel so I can power it from a shield I built. Is this not good? Is that hot chip normal and ok?

I just dont want to damage the board.

2

The chip next to the barrel connector is the linear voltage regulator. It takes the 12 volts and drops it down to what the board needs. The higher your input voltage, the more voltage is must drop. With a linear regulator like this, the only way it can do that is to “burn it up” as heat. Although the chip may be too hot to touch it may be ok. But it would be safer to run it at a lower voltage. A 9V wall wart would likely lower the temperature (and perhaps the life span) of the regulator.

edit: A 9V wall wart would likely lower the temperature (and perhaps RAISE the life span) of the regulator.

3

This sounds normal. Components can be too hot to touch at around 50 degrees C, which is a lot less than their acceptable operating temperature.

4

Long as you don’t hear a hiss and have the part number of the component branded into your finger, you should be within the operating temperature of the part :smiley:

5

Every (linear) voltage regulator I’ve come across had over-temperature shutdown built in, so it should never get to those temperatures :slight_smile:

6

Thanks all. Just making sure I didn’t miswire something and be damaging my board.