I had to spend a lot of time running simulations, before I could comprehend the operation of a buck converter (also boost and buckboost types).
I particular found the Falstad simulator to be helpful. It is animated. I use it as an alternate to my own homebrew simulator.
https://www.falstad.com/circuit/
Click 'okay' in the window asking to load the applet. You can create a circuit to look just like your schematic.
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You are looking for the correct value inductor whose time constant is such that it will ramp up to several amps while switch 1 is closed. This current powers the load and load capacitor.
When switch 2 is closed, the coil is supposed to discharge several amps, maintaining power to the load and load capacitor.
Both events occur inside one 330 kHz cycle.
Assume an inline resistance of 0.1 to 2 ohms while charging the coil.
Assume a very small resistance for the load capacitor. Try .01 ohm (a reasonable figure). Most likely it's to make the simulator happy.
Attach a load of 0.8 ohms. ( 4V / 5A )
Try various values for components.
Look at some buck converter projects on the internet.
Look up threads related to 'buck', using this board's search.
---------- Post added at 13:04 ---------- Previous post was at 12:52 ----------
Also:
* The figure for ripple current means that the coil does not fully discharge. It is always conducting to some extent. This makes for subtleties in behavior that we cannot be expected to understand until we observe waveforms in various experiments.
* A real circuit will use a mosfet/transistor for switch #1. Typically switch #2 is a diode (fast response type).