Newbie question:

I have an Arduino board supplying 3.3v. I'm looking at LEDs. I've found one which I like, but it has a forward voltage of 4.4v.

Aside from any consideration towards resistors, would this be an optimal setup / would it break either the LED or the board?

I'm unclear as to whether the board would be able to supply enough voltage to power the LED?


1 Answer 1


Nothing will break, nor will anything light up.

If you must use the LED, you need a secondary voltage source. One can be made using a step-up circuit or boost-converter, and there are likely many questions about that here.

Another option is taking a secondary voltage in, for example 5 volt from any USB charger and just use the Arduino to control it, using a transistor. This might work, though it's cutting it a bit close.

  • \$\begingroup\$ Thanks. Thats what I assumed. In laymans terms, I presume there isn't enough horsepower to power the LED. Smaller LED it is as I'm using a battery to power the device. \$\endgroup\$
    – Mr T
    Aug 20, 2017 at 14:23
  • 1
    \$\begingroup\$ @MrT Perhaps not so much about horsepower - there are very powerful LEDs running on lower voltages. The actual chemistry making up the different colors are often what makes them have different forward voltages. You could add the datasheet to the question if you like. \$\endgroup\$
    – pipe
    Aug 20, 2017 at 15:17

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