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I am creating a pcb with ESP12-F which will contain Neopixel Ring 12. As this will run 24/7 and Neopixel even when completely off drains about 15-20mA and I will have several of those the consumption will be pretty significant.

So I want to turn of VCC to Neopixel when not needed (which will be most of the time) so I can get the power consumption to some reasonable level.

Unfortunately, I am noob regarding MOSFETs and transistors and I did not find any specific solution, only some brief descriptions as that Neopixels should be turned on/off on VCC (so P-channel MOSFET) and not on GND (N-channel).

I found that P-channel MOSFETs are quite complicated when switched with 3V3 and probably will need to be chained with another MOSFET or transistor.

So my question is, can you please provide schematics of switch which will turn on/off the NeoPixel with GPIO on ESP (3V3 logic)? I don't want to use relays as they are pretty loud and big.

I have already implemented 3V3-5V logic converter for the NeoPixel using MOSFET (from some tutorial) and that is working like a charm (the LED1 is alternative for the NeoPixel Ring - it will either contain NeoPixel Ring or single NeoPixel Led, never both; I accidentally swapped 5V and GND labels on image):

Current connection

EDIT:

I found this answer here, and it looks like what I might need, but specified MOSFETs seems a bit overkill as worst case load (which will never happen in my case) is 720mA and those MOSFETs are made for load of almost 10A. Can you please suggest better MOSFETs for 5V 720mA? At least physically smaller.

https://electronics.stackexchange.com/a/353222/209504

Jakub Zacek
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  • In selecting an FET you want to find something that will be fully "on" with the gate drive voltage you can apply. Typical VTH values are for really miniscule current, for meaningful current at low loss you may need to apply quite a bit more. Lots of these "how to" articles are written for an audience afraid of surface mount, but most modern FETs are SMT, so there are few through hole choices with low VTH and they tend to be TO220 etc. You seem willing to use a modern package, so pull up a catalog and start shopping. Buying recommendations aren't really on topic here. – Chris Stratton Jan 10 '19 at 20:10
  • Thank you for the answer! Well, I am one of these people so, I was aiming for non-SMD/SMT components, e.g. MOSFETs with this [casing](https://components101.com/2n7000-n-channel-mosfet). I am really not that skilled with SMD soldering and I don't have proper equipment either. I suppose VTH is same as VGS? From what I understood this value needs to be in range for difference between load voltage and control voltage so in my case 3.3 - 5 so something around -1.7V am I right? As I said, I am really new to this and I am overwhelmed, that's why I asked for a specific solution for this case. – Jakub Zacek Jan 10 '19 at 20:36

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