Im woundering if I could just use a cmos instead of a nmosfet. This will be used for low current switching.?

Answer 1

CMOS: Complementary Metal Oxide Semiconductor

CMOS is typically used in digital circuits...It's used to implement logic...It's composed of both nmos and pmos fets.

So if you implementing digital logic you should use CMOS if analog CMOS doesn't make any sense.

Answer 2

You can use either type, but the circuit will not be exactly the same. It is easer to use a CMOS switch which usually come in the form of an integrated circuit with driver circuitry built-in. However either nmos of pmos individual transistors can be used for current switching, but you have to watch the potential levels of the gate, source and drain to make sure the device turns on and off properly.

EDIT: If your device is battery-operated, check mosfet specs for a gate turn-on voltage that is low enough. If you use a two-battery circuit (3V) you will have to find a mosfet whose "on" voltage is about 1-2V. You will have to decide whether you want an enhancement-mode mosfet (off when gate voltage is low) or a depletion-mode mosfet (on at low gate voltage). The latter are more common. Check the "on" resistance (drain-source) to be sure that it is low enough for the load you are driving. Since you are switching current (maybe to a motor), your switch will be in series with the load, and you want to make sure the voltage drop is not excessive.

For more info, see http://en.wikipedia.org/wiki/Mosfet#Modes_of_operation

Answer 3

What we are trying to do is make a wireless switching module.
Something to do a variety of switching possibilities like control a toy
or something. So to keep our module small I want to stay away from relays and try to use mosfets. Any help is appreciated, but if all you can do is put down those trying to learn then save your typing skills for the chat room.

Answer 4

What exactly are you trying to do? Do you even know what CMOS is? IT's a process that contains both NMOS and PMOS devices.