How can Arduino UNO/Nano generate 3.3 Volt?

[shanto_kushtia]

I see Arduino UNO and Nano has only one voltage regulator which is supposed to be 5 V output regulators. So, how 3.3 volt is generated in the 3.3V written pin?

[pert]

I moved your topic to an appropriate forum category @shanto_kushtia.

In the future, please take some time to pick the forum category that best suits the subject of your topic. There is an "About the _____ category" topic at the top of each category that explains its purpose.

This is an important part of responsible forum usage, as explained in the "How to get the best out of this forum" guide. The guide contains a lot of other useful information. Please read it.

Thanks in advance for your cooperation.

[DVDdoug]

I'm going to take a guess...

I'd guess it's marked 3.3V for pin-out "compatibility" with other versions of the Nano that actually use it.

[build_1971]

With a zener? (Not acc. to schematic below).
The 3v3 is available as a reference voltage. Not as a power source...

[srnet]

Check the UNO swchematic for regulators;

arduino-uno-schematic.pdf

[van_der_decken]

@shanto_kushtia

I see Arduino UNO and Nano has only one voltage regulator

Look again.

The Uno has two voltage regulators, a 5V and a 3.3V.

On the Nano, 3.3V is generated by the FT232 IC.

[Wawa]

+1
The Uno has a dedicated 3.3volt regulator, which is the tiny 5-pin smd chip next to the larger 5volt regulator. It can provide 150mA (not 50mA as stated in the spec sheet), which comes from the 5volt regulator. Small board Arduinos just steal 3.3volt from the USB<>Serial chip, which can only safely provide 30mA.
Leo..