A converter controller is disclosed. In one embodiment, a controller for a flyback converter includes a converter and a flyback controller. The converter is coupled to the flyback converter for receiving an auxiliary voltage and for generating a constant power voltage. The flyback controller is powered by the constant power voltage for controlling an output voltage of the flyback converter. Furthermore, the flyback converter comprises a transformer with a primary side and a secondary side. The output voltage and the auxiliary voltage are produced at the transformer.