Hello i want to control to components from Arduino digital pin which is not possible i believe so i want to use an MOSFET…i want to power IC4066 which needs 5v and Car remote key fob which needs 3v (as it needs just 3v can this directly powered from Arduino digital pin?) i would like to know the perfect MOSFET to deliver current for both the components… Thank you
as it needs just 3v can this directly powered from Arduino digital pin?)
There is no "perfect component" you need to tell us how much current you want to switch. Also if you need a top switch, switching to positive, or a bottom switch, switching the ground.
as it needs just 3v can this directly powered from Arduino digital pin?
You have voltage and current mixed up... (at least in normal voltage control) A devices takes the current it needs and can, so if 10A is available it can just pull 20mA no problem. But a voltage is forced onto it. If it's connected to 5V the device can't just magically take 3V of it....
Most circuits cannot be powered from an Arduino pin because of two things:
The pin cannot handle the inrush current to the decoupling capacitors in the circuit.
The Arduino pin is not a stiff voltage source at all - about 30 to 40 ohms of source impedance,
rather than the 0.1 ohms or less of a decent voltage regulator - many circuits assume a
decent quality supply.
A high-side switch from 5V or 3V can be made from a PNP transistor or a logic-level p-channel MOSFET.
With a PNP transistor a 1k base resistor would be suitable, connect the emitter to the voltage rail (5V
or 3V), collector to load. Your 5V load is very small I think. Don’t forget a CD4066 needs a decoupling
With a logic-level p-channel FET, source to 5V or 3V supply, drain to load, gate to Arduino pin (perhaps
with a 10k resistor for soft-switching)
With both methods a HIGH on the Arduino pin will mean the switch is off, a LOW turns it on.
Don’t use a darlington
how 'bout this?
Rubbish, it is not a logic level FET so why it is marketed for an Arduino or Pi is anyone's guess. You need 10V on the gate to fully turn it on and even so the on resistance at 0.27R is rubbish these days.