How power a 3.3V display from Arduino nano?

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1

I have a 2.2" TFT which I'd like to control with an arduino nano. This unit communicates with 3.3V data lines so I will use a 4050BE to convert the SCK, SDO etc lines to 3.3V

I need to provide a voltage to the Vcc and LED pins though and my options seem to be the followings:

  • Using the 5V pin of the nano (the Vcc and LED seems to be 5V tolerant)
  • Using the 3.3V pin of the nano
  • Using the 5V pin of the nano with an AMS1117 voltage regulator (convert the 5V to 3.3V)
    Please help me out by explaining which one is the best option. (currently I don't want to add an external 3.3V or 5V power source, so I need to use one of the three options above).

Also for educational purposes it would be nice to hear about the disadvantages of the options.

Thanks!

2

The first question to answer is how much current the display and LED require.

  1. "sems" is troubling. That means, to me, that it works until it doesn't.
  2. Can the Nano 3.3V regulator handle the current? The Uno 3.3V regulator is good for about 50mA so The Nano could be about the same. I found this.
  3. Probably the best option is the 1117 as it can supply at least 500mA with no problem (if its supply (Nano 5V) will do it).
3

Nano's 3.3V comes from the FT232 chip, only 50mA is available.
Uno has a 3.3V regulator, rated for 150mA.

I'd go with option 3 also.

4

Thanks, I will go with the voltage regulator option then.