Drive a 3.7V DC motor with a max load current of 110mA

[Kian]

Hi all,

I just tried to drive the motor with the original schematic I provide using the MGSF1N02LT1G (N-Channel) MOSFET. The supply voltage is 4.5V (3xAA batteries).

I didn't use a gate resistor but have a 100k pull down resistor at the gate. The gate is driven by an arduino microcontroller with 3.3V output.

Everything seems to be working well. I used an amp meter to measure the current through the motor and got in excess of 110mA. So the solution does work!

 

[audioguru]

Then you are lucky to get a sensitive Mosfet, the datasheet shows that some of them need 4.5V for the gate to work fairly well and 10v to work very well.
If the mosfet fails and you replace it then the motor will run poorly if you get a Mosfet that is not sensitive or if you make many circuits then some might work and some might not work.