I'm using a PNP MOSFET to replace a physical button. When I ground the lead I've attached to bypass the switch, the action I need activates (a notification light comes on - it's the activator button on this barcode scanner), so I know I'm working with the right lead.
In the same test, when I insert a DMM into the loop, I see that when pressed, there's about 60uA going through it.
My circuit is as follows:
The gate voltage goes from 5V to 0V when expected, and when I put a DMM between the drain of the MOSFET and ground, I can see ~55uA when the MOSFET is activated. However - the indicator light doesn't turn on.
Any ideas of what I should look for?
The external input is the circuit described in this question, but with a P channel instead of an N channel, as my sensor output goes high when it needs to be off, and low otherwise.
Here's the mosfet I'm using: http://www.diodes.com/datasheets/ZVP4424A.pdf