I would like to power ~100 LEDs from an WS2812 LED strip and an ESP8266 with my power supply of 5V / 5A.

I've read a lot of tutorials and advices but I'm still not 100% sur that all my assomptions are corrects.

The current regulator on the board ( AMS1117 ) does not accept more than 1A. And as the maximum current used from the ESP8266 is around 400mA there's only 600mA left if I want to power the board with the Vin PIN ? Is that right ?

Then I've calculated how many current my 100 LEDs would use. Things begin to be complicated landing on the WS2812 Datasheet

WS2812 Datashit

What's the difference between "Power supply voltage" and "Input Voltage" ? I assumed that thoses LEDs would work with 5V... Seems like it better should be 6~7V ? Does it mean that running with 5V the light are less bright (I mean even theorically ! I want to understand even though 1V won't be noticable in pratice) ?

And now the second array : enter image description here

Vdd is now 4.5~5.5V as an assumption ! What is Vdd ?

Let's do the math with 18.5mA As mentioned they are 3 LEDs by units so it's 20x3 = 60mA each ... The project would then use 18.5x100 = 1.850A 60x100 = 6A

Which is higher than the 1A of the AMS1117 regulator.

So, the idea is to power the ESP82 on Vcc. But how should I drop the current from 5 to 3,3V

Does thoses little boards should be used as the "voltage dropper" in the schematic ?


simulate this circuit – Schematic created using CircuitLab

Thanks a lot and don't hesitate to point my errors in my reflexion.

  • \$\begingroup\$ The AMS1117 is voltage regulator typically used to convert 5v to 3.3v. You mention having an AMS1117 and wanting to generate 3.3v. Any reason you cannot use it? \$\endgroup\$ Aug 10 at 0:50
  • \$\begingroup\$ Yes ... Too much current ! My LEDs would use almost 6A and the AMS1117 can only handle 1A MAX ... So I can't right ? Or can I ? \$\endgroup\$
    – Seba99
    Aug 10 at 10:55
  • \$\begingroup\$ Your LEDs are 5v and thus cannot be connected to a 3.3v regulator. Well you could connect them but they won't work. Instead you would power them from a 5v supply. \$\endgroup\$ Aug 10 at 14:21

2 Answers 2


Your first table is the Absolute Maximum Rating - that heading is at the bottom of the previous page - sloppy page layout. The device may be damaged is you operate beyond those ratings.

"Tpy" is a typo for "Tpy" = typical.

Vdd is the positive power supply, as stated in the header of the Electrical Characteristics table.

  • 1
    \$\begingroup\$ "Tpy is a typo for Tpy" has a typo itself, should be "Typ" \$\endgroup\$
    – Ben Voigt
    Aug 9 at 20:43
  • \$\begingroup\$ @BenVoigt: Arrgh! damn keyboard! \$\endgroup\$ Aug 9 at 21:50

The first table in your question contains absolute maximum ratings. They are not recommended operating conditions. Note that the other electrical specs indicate Vdd=4.5-5.5V; presumably the same applies to Vcc. Vdd is the LED power, Vcc is for the control circuit.

"Tpy" is probably a typo for "Typ."

If you run the controller at 3.3V, you probably want to use the same supply for Vcc. The spec doesn't say whether that's recommended, so best bet is try it. If not, you'll probably want to use level shifters to get from 3.3V to 5V. Usually separate supplies can have separate voltages, but in this case it may be that they just needed Vcc to be isolated from LED noise.

If you really want to use this particular supply, you can use two and hook up half the LEDs to the second supply. The grounds should be connected together, but not the power outputs. You may need more than you think, though...that 18.5 is a maximum output current on Dout. The LEDs themselves can take 20mA for each color, or 60mA total per device.LED characteristics

This means that a 1A supply can handle up to a maximum of 16 devices.

  • \$\begingroup\$ I've edited the question with a schematic ... Would it be possible to wire it like that ? Using those circuits ? \$\endgroup\$
    – Seba99
    Aug 10 at 0:10
  • \$\begingroup\$ Assuming you have the data daisy chained properly, you'll need one level translator between the ESP and the first LED in the chain to boost the 3.3V output to 5V. If the pin is 5V tolerant, set it to open drain and just use a pullup to 5V. \$\endgroup\$ Aug 10 at 16:02

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