I've been trying to get into some low level electronics to explore to "Internet of Things" and still struggling a little with MOSFETS.
I'm trying to make a single push button act as a latching power switch for a microcontroller, then act as an input button when the mc has powered up (further details in my previous question).
Following the suggestion to use a BSS84, I discovered the mircocontroller I'm using (ESP8266 ESP-12) draws a current of around 300mA and, looking at the datasheet for the BSS84, I saw the continuous current draw is -0.13A?
This is where I get confused a little. I understand the continuous draw needs to be adequate (130mA is too low) but why is it +/-?
Does the current not flow from Drain to Source? If so how can there be +/- voltages? (I realise I may have a very poor understanding of FETS)
I'm aiming to use a logic level mosfet to provide at least 300mA when the gate is connected to ground. Would something like the IRLML5103TRPBF work or are there better options?
Thanks in advance for your help. Apologies if I've got entirely the wrong idea and sounds like a crazy person ha!