This circuit enables a controlled soft start of a 5V power rail using a P-channel MOSFET.
An external signal activates an N-channel MOSFET, which gradually pulls down the gate of the P-MOS through an RC network.
As the gate voltage decreases, the P-MOS begins to conduct, allowing 5V to reach the output.
A 2 kΩ resistor and 1 µF capacitor are connected at the output to emulate a load, demonstrating both inrush current during charging and steady-state current.
This setup allows safe and gradual power delivery, minimizing stress on components during startup.
An optocoupler can be added at the input to provide galvanic isolation, allowing control from external systems without introducing ground loops.
