I am designing a handheld Arduino project that will run from a 1s 3.7v lipo.
The device will have two tactile switches for functionality and I would like one of these to also act as a power on button. After a bit of reading online about latching circuits I found the one in the image attached.
I am in the process of building and testing this but I would like to know what is the best way to achieve the same result but with absolute minimum power draw.
I assume the transistor will require a small amount of current and keeping the mosfet on will also require power, also would I be right in thinking the mosfet itself will lose some power due to efficiency losses.
The project will consume somewhere in the region of 40mA at max draw with it being idle a lot of the time. So no high power capable devices are required.
If anyone could offer an alternative with minimum power loss I would be grateful. Many thanks.