Techniques are disclosed to regulate the output power of a power supply. An example regulator circuit includes a feedback circuit coupled to generate a feedback signal in response to an output of a power supply. The feedback circuit includes a voltage regulation circuit, a current regulation circuit and a transition region regulation circuit coupled to sense the output of the power supply and generate first, second and third regulation signals, respectively. The feedback signal is responsive to the first, second and third regulation signals. A switch coupled to an energy transfer element coupled between an input and the output of the power supply. A controller is coupled to the switch to control switching of the switch to regulate the output of the power supply in response to the feedback signal.