I am designing a simple inrush current limiting circuit with a P-Channel MOSFET:
The simulation shows a 48V source that switching on with a fairly fast rise time of 1ns. The Drain-Gate capacitor Cinrush shall cause the MOSFET to slowly turn on. However, during the 1ns rise time of the source, the current shows an extreme value of 1kA.
What is causing this high current peak?
EDIT: Also is my understanding for this circuit correct: When first switching the source on, it is only limited by R1. Then Cinrush will be charged up to VG, which is defined over the voltage divider R1 & R2. The time constant is R1*Cinrush (neglecting all parasitic)?