In described examples of methods and control circuitry to control a multi-level power conversion system with a flying capacitor, a power circuit regulates a regulator input voltage signal to provide a supply voltage signal to the control circuitry. A power switching circuit couples the regulator input to a first terminal of the flying capacitor in response to a second terminal of the flying capacitor being coupled to a reference voltage node in a given switching cycle, and couples the regulator input to the second terminal in response to the first terminal being coupled to an input node of the power conversion system in the given switching cycle.