Hi, I want to use a set of components in order to isolate a few sensor's power from the micro controller's(esp32 in my case) power(3v battery). For now I used a mosfet, which its gate is connected to GPIO12. I want it to disconnect the sensors from their power completely(maximum consumption of few…

N channel MOSFETs are best used for low side switches. The load is between Vcc and the drain of the MOSFET. Source to ground. The Rds(on) of the MOSFET is around 2Ω. Kind of on the high side for MOSFETs. What is connected to the 3.3V_SW (show the rest of the circuit on the schematic). The 10K …

This is a good source on using transistors as switches: Transistor as a Switch

Hi, Thanks for the replies. Attached 2 screen shots, of what I understood should be the schematic, and the connections that goes after 3.3V_SW. If I understand correctly, GPIO=HIGH output will be 0 and the opposite, is there a simple way to make it the other way around(GPIO=HIGH->OUTPUT=HIGH)? I…

No, that's not the way. Now you're connecting 10k in series with your sensors and that's not going to work. You place the sensors (loads) in the place of the 10k resistor. The drain of the mosfet becomes a virtual ground as it turns on.

And that depends on if the sensors like having their grounds switched. Removing the ground while having the positive power still connected can lead to back powering the sensor, often to the determent of the sensors well being. May be better to use a high side switch using a P channel device to con…

Confused. Why do you want to switch 3.3volt power to addressable LEDs that need 5volt to work. Leo..

[image] groundFungus: And that depends on if the sensors like having their grounds switched. Removing the ground while having the positive power still connected can lead to back powering the sensor, often to the determent of the sensors well being. May be better to use a high side switch using a…

I think I'll use high side switching because all the reasons above. Does it wastes less current than low side? @groundFungus yes, the sensors take a lot of current in compare to what I need(for it to work on ~20uAh in sleep mode), I prefer disconnecting them this way than going in to sleep mode com…

[image] omri1: Does it wastes less current than low side? It won't make a real difference.

Mosfet as a power switch for low power consumption

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ShermanP July 6, 2021, 5:37pm 7

For a high-side switch you need a P-channel mosfet. Something like this:

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Mosfet as a power switch for low power consumption

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