Simulation of a classic buck converter for 30V to 5V.
NFET used as the high side switch due to low on-resistance and fast switching capability.
PWM signal at VIN+10V is used to switch the NFET on and off at 100kHz and 15.5% duty cycle to generate 5V at the given load.
100uH inductor ensures continuous current with a manageable ripple at 100kHz, balancing energy storange and output stability for ~5v.
10uF cap smooths voltage ripple and absorb inductor current transitions with low ESR to reduce output voltage ripple.
The parallel resistor is due to the light load to help balance the circuit. ~95 ohms seems to be the sweet spot to prevent drift up or down and balance energy in = energy out.
