So for a pure hysteretic converter, we can probably agree that a Bode plot isn't possible. It's a large signal control scheme and there's no small-signal linear system analysis or measurement possible (?). However, there are some control schemes like TI's DCAP constant-on time control that uses the ESR of the output caps as current feedback. If you use a very small signal disturbance you can measure a Bode plot with these devices, where the crossover usually measures around 300kHz (!). My question is what does this Bode plot mean with this topology? I think it may by valid for small disturbances, but I don't think it will say anything about the response of the converter to large load steps and releases where the converter will be more like a pure hysteretic controller.

Any feedback on this or the general subject of Bode plots on these kinds of controllers would be appreciated.

Thanks,