LTspicePowerSim

Boost — PI regulation

LTspicePowerSim's 2.5 V to 3.3 V boost, regulated by a PI-controlled switch.

Press Run: the example simulates in your browser. Open and simulate takes it to the full app, where you can change it.

Try this

Double the load resistance and check that the output stays at 3.3 V. Then press Run again.