Using a power jack connector with three pins

[nick]

I want to use a power jack connector in my project.
It will be identical to the one that the arduino has.

This particular jack has three pins, one Vcc, one GND, and the other connects to one of the other pins, in order to know when a power jack is inserted.

I am not interested in this kind of knowledge, so i only plan to use two of the three pins, Vcc, and GND.

Before i knew about the three pins, i assumed there would be two. So in my schematic, i used a part with two pins.

This is what i used:

So now that i have a part with three pins, but since i only plan to use only two, do i have to change the part in my schematic editor? Or do i leave it like this?

Considering that the part has three pins, but i will use only two, what do i put in the footprint editor?

This is the component i will use.

DC Female Barrel Jack 5.5x2.1 - Socket Power Connector (DC-005)

The website does not offer a schematic, but it is a common power jack, featured in arduinos and their shields.

[SembazuruCDE]

Personally I would switch to a 3-pin symbol so my schematic reflects reality. All part of the iterative process of PCB layout.

There is a different symbol that you can use. Search for barrel jack and choose the correct one depending on which pin is switched (2 or 3). Then either put a non-connect x on the switched pin or connect it to the ring pin (what is pin 2 on your current symbol).

Unfortunately, the barrel jack symbol has all the connections on one side instead of on either side so you will have to shuffle your schematic a bit to get it to fit.

Edit: If you connect the switched pin to the ring pin then you don’t need to worry if you choose the wrong symbol (i.e. switched pin on 2 or 3).

[nick]

Thank you!
Very valid points.

Do you happen to know the valid footprint as well?
Also, the pins that are connected are the GND pins correct?

[paulvdh]

The Footprint Editor has a nice and simple search function.
If you type “barrel” in the search box, then it gets a list for you of all footpints that have the string “barrel” in the name or description:

That Connector_BarrelJack:BarrelJack_Horizontal might be it, but maybe one of the 7 others fits your particular connector better.

Some notes:

• Some of these footprints have pins that are for mechanical strength only.
• You have to ckeck with your schematic symbol and verify that pins match, or else the polarity of your power connector will be wrong.