Hardware question about powering an ESP32 S3

[alan-bc]

I just bought an ESP32 S3 for a specific project.

I want to be sure I power it correctly. My options are

• USB

• 5 volt input

• 3.3 volt pin

USB is the easiest, and least desirable.

The 5 volt input is easy; I have lots and lots of nice 5 volt supplies around. But that still leaves the tiny little 3.3 volt regulator on the board, which makes me a bit nervous.

Supplying 3.3 volts directly via the 3.3 pins seems like the best plan but I don't know how the on-board regulator will behave being "backpowered".

The overkill option might be to supply both 5 volts as well as 3.3 volts.

Any thoughts .. opinions .. advice greatly appreciated.

[mikemoy]

I just bought an ESP32 S3 for a specific project.

Not to clear here. Did you buy a module, or the IC?
what exactly did you buy.

[Craige Hales]

When I started with ESP32, it took me a while to figure out the product matrix had an axis of IC (SOC, system on a chip), Module, Dev board, in addition to the axis of <no suffix>, S<n>, C<n>, H, 8266. (And another axis about the WIFI antenna.) Mostly I get 3rd party development boards on Amazon, but I did get some modules and hand soldered them to a PCB.

Dev Board
These are 10 pins per inch. Hand soldering is easy. Check the schematic for your board; most likely it expects 5V on the VDD_5V pin. All the Amazon vendors seem to make small changes to the dev boards: pins, leds, size, camera, usb. You might not find a perfect schematic for any particular board; a magnifying glass is helpful.

DevelopmentBoard.jpg (17.47 KiB) Viewed 36 times

The dev board has a module soldered to it, at the top in the picture above.

Module
These are 20 pins per inch, hand soldering is possible. Check the module doc; most likely it wants 3.3V. The module has a printed antenna or a connector (printed in these pictures).

Module.jpg (17.77 KiB) Viewed 36 times

If you pry off the metal cover on the module, there are tiny ICs inside, and maybe some external memory.

IC (CPU)
The IC is 7mm -- tiny. Beyond my skill level.

IC.png (12.01 KiB) Viewed 36 times

Inside the CPU it is turtles, all the way down.

[alan-bc]

I just bought an ESP32 S3 for a specific project.

Not to clear here. Did you buy a module, or the IC?
what exactly did you buy.

A module. 44 pins. Same pinout as the Espressif version, but clearly a different board. Slightly wider, an extra LED, different layout of active parts and switches.

For my rev 1 PCB, I added extra filtering at the 3.3v and 5v pins .. 100u electrolytic, 10u tantalum, .1u ceramic.

Currently running it off USB power without a problem. Leaning to 5v power pin long term.