Quick Question, about a Regulator LM2575T-ADJ

Hello Arduino Forums
This is my first post so sorry if its a bit of a mess

Basically im triyng to power an ESP8266 and i only found this regulator LM2575T-ADJ by luck on a board i had

My question is, can i make it drop my 5v source to 3,3v? By the datasheet i found (with the little knowledge that i have in the matter) i understand i could. http://www.ti.com/lit/ds/symlink/lm2575-n.pdf

But, i want to be careful not to burn my ESP8266. Can someone better than me at electronics say to me if its possible or safe?

In case of being possible/safe can someone point me to a forum of how to do it? or make a little explanation?

My Regulator says written 81BH LM2575T-ADJ P+

Thanks in advance for any reply.


That is a switch mode regulator, it requires some external components to do it’s thing.
But you found that on the 1st. page of the datasheet, right ?
To use this part, you also need to use the accompanying parts, either from the source board or buy new ones.
The datasheet also tells you how to do calculations so you will get to the 3.3 volts.

But if you have to ask about that, i’d rather advise you to get a module doing this for you.
So search for “adjustable voltage regulator module”
It will have a potentiometer that allows you to set the desired output voltage, and not be too large in size.
It’ll set you back some US$ 2 plus shipping, so that would be the smarter thing to do.
And way faster than learning and developing the power supply you want it to be.

I’m all for learning and teaching about how things work and are supposed to be done.
But that’s not in all cases the best advice to give.
So if you have time to learn about this and still want to go that path, you’ll be welcome to do so.
Else just order one of these modules and go on with your project next weekend (or next month if you order from China).

Welcome to the forum.

Please read the first post in any forum entitled how to use this forum.

What model/board is your ESP8266?
Does it have a USB socket on it to program with?
If so the it already has a 3.3V regulator on board to supply the ESP8266 IC.

Can you post a link to data/specs of your particular ESP8266 assembly, there are literally hundreds of PCB variations concerning the usage of this IC.

Thanks.. Tom.. :slight_smile:

AP1117-33's are cheap, you don't have to take a course on switch mode power supply design to use one,
the choice is yours... Switch mode converters really need careful layout on a PCB, that's a lot of trouble
to go to if not already designing a PCB.