This is my circuit. An MCU gpio pin should control the power of another IC. Because the component requires more current than the gpio pin can drive, an N-Channel MOSFET is used. This is IC has no ENABLE/SHUTDOWN/RESET pin. VCC may be different from MCU VCC. However in this configuration a virtual ground for that component is created because of the RDS_ON resistance of the MOSFET that causes a voltage drop.
A certain number of question arises:
- Is this a good way? Is there a better way?
- In order not to left components ground floating (if the MOSFET is not conducting) is this 100K pull-up resistor required or is it even allowed? Is a floating ground a problem in most situations?
Update: New circuit based on Michael's reply Unfortunately wrong. If I understand, the circuit can even be simplified by using one logic P-Channel MOSFET like following circuit (assuming SSM3J328R P-Channel MOSFET):