In this circuit an Arduino digital pin drives the Gate of a N-MOSFET. When the pin is HIGH, current can flow from the H-Bridge GND to board GND. When it's LOW, current can't flow. What I need is to switch the H-Bridge ON/OFF in order to stop its quiescent power.
Everything works fine except when I use PWM signals in the H-Bridge INPUT pins. In this case, when the MCU suddenly sets the Gate pin LOW, the motors still move a little bit or they make a noise just like they are receiving power but not enough to move.
The MCU is working at 16 MHz speed, and the PWM instruction used is analog.Write(pin, 180); (range values 0-255) (*I name the instruction only to help calculate the switching frequency)
I'm quite sure I should have put a pull-down resistor in parallel from the Arduino digital pin to GND. In other words, pulling down the Gate to 0V. I tried to stick manually a through-hole resistor but it didn't solve the problem.
The N-MOSFET is: AOD2922