3.3 Volts to 5 Volts the easy way


It doesn't get more simple than this...

The above circuit worked to let a 5 Volt servo work on a 3.3 Volt signal. This DOES NOT convert power so connect the servo power connections to 5 Volts and ground. This only converts the low power signals (before this my servo wouldn't move!)

Now, the resistor is 1000 ohms or 1 K (brown, black, red). Wattage isn't citical. The diodes are 1N914 or 1N4148 any good silicon (Switching) diode should work.

If you have a really fast signal I am pretty sure this wouldn't work. It sure worked well for my 5 Volt servo!!! (Re-check all connections before you use this and as usual, your milage might vary...)


Is D1 necesarry?

A quick simulation using EasyCircuit on Android show no difference with or without D1.

When the 3.3V output goes high there will still go a small current this way from the 5V via the 1000 ohm resistor.

You are probably correct…

Maybe it functions as a reverse voltage protector or a overvoltage protector???

I don’t know, I haven’t did any circut analysis. The image is copied direct from a pdf document.

I just know the circuit works and now the “fear” of using a 3.3 volt processor with hardware needing 5 volt signals (like anything related to the Arduino, a 5 volt system).is gone.

More and more of the new systems will be 3.3 volt, as that is becoming the new “standard”. Being able to connect to them is importanf.

NOTE: I chose the 1k (1000 ohms) resistor, other values might work better (depending on the equipment used).

(5 volts to 3.3 volts is even easier using a few resistors as a voltage divider, and just a few calculations.)).


I think that the D1 and its 3.3V source shouldn’t be there, at least for what I understand of the circuit.

I think this (very cool tip)

I think this (very cool tip) should be (cleaned up in respect of the comments) and then be posted as a “Tip / Walkthrough” -> That way people can find it easier, thanks :slight_smile:


This would NOT be a good circuit for the “Tip / Walkthrough” area. It works with most hardware, but not all  (some of my friends told me about this.).

It is an interesting circuit but just not a reliable tip.