I'm currently using an N-channel MOSFET (PSMN0R9-25YLC to drive a load as shown below:
The Arduino is providing a PWM signal with a voltage from 4.2V-2.5V depending on the charge of the battery and driving the gate at 490Hz. The voltage between the drain and the source also reflects the voltages above as well. I'm also pulling about 5 Amps at any given time.
After about 30 seconds of use the MOSFET is extremely hot to the touch and I can actually hear it switching the load. Looking at the specs of the MOSFET I believe it should be able to handle this no problem, so what could be wrong?