Custom made Arduino board with original Ethernet Shield help!!

Hello all,

I have made a custom Arduino board with a 3.3v Simple switcher from TI - LM22680. The board consists of just the 3.3v power supply, the Atmega328P, its 16MHz crystal, the 22pF decoupling caps.

I have all the pin coming out of the Atmega directed to the same pinouts as that of the original Arduino board. Now I want to use the original Ethernet shield with my board but I want to do it without using the 3.3v regulator on the Ethernet shield. I want to use the LM22680 to power the Ethernet shield as well. So how do I do this?

Should I just remove the 3.3v regulator thats there on the Ethernet Shield?? My main question is that how should I bypass the voltage regulator on the Ethernet shield so the it'll use the supply from the LM22680.


Hi There,

Their might be several ways you can resolve the problem. The most simplest way would be to remove the 3.3Volts regulator on Arduino shield and connect the output pad to your LM22680 output.

You can use a heat gun to remove the 3.3 volts regulator. It would make the process easy. If you don't want to solder the wire manually from 3.3V output from LM22680 to Ethernet shield, you can connect 5V jumper on Arduino board to 3.3V. Thus, Ethernet Shield would get 3.3V. On the pad of the voltage regulator you just removed, you can short the input and output pads. That should fix the issue too.

All the best, Hani Abidi

Hi Hani,

Thanks a lot for your reply.

Yes I have connected the 5V and 3.3V jumpers together on my custom Arduino board so that both get 3.3V from LM22680. Now I'll just remove the 3.3V regulator on the Ethernet Shield.