Arduino Nano Real VIn Range

Hi together,

I have here an application with an Arduino Nano (5V). The power supply is a 5V DC / 3A wall power supply. I have many of this supplies here and when I measure the output of this devices I read between 5,4V up to 5,8V (maybe less under load). Now my question:

What is the real range of VIn? The Atmega328P-AU can be used below 5V and also the only other component in my application, a DS3231, can be driven below 5V. On my workbench everything works fine even if I supply 4V to the VIn. Ok, there is a drop of the voltage due to the LM117IMPX-5.0 of about 1V.

What is the downside of using 5V at the VIN?

In the specification the minimum voltage of VIn is 6V and the maximum voltage of 5V is 5.5V. I have no space for an addition DC/DC-Converter.

Thanks in advance for your answers.


These supplies often dip when a load is put on it, 5v should be its output at 3A load.
If you not too sure put a diode in series with its output before connecting to the 5v line - that will drop 0.6 volts and gives the added protection if you wire the supply the wrong way !

You can connect direct to Vin , but you’ll find the 5v line is about 4.6 or so and it may be unreliable .

Vin would need 6V to “work properly” as a regulator. Otherwise it will probably just output Vin-
But the other components on a Nano will happily work at voltages below 5V, anyway (possibly as low a 1.8V, depending on speed and fuse settings.)