Apparatus providing an integrated transformer are disclosed. An example apparatus includes a power conversion system including a switching circuit including a first primary side transistor coupled between a first input node and a switching node, and a second primary side transistor coupled between the switching node and a second input node, a series circuit including a transformer primary winding, a capacitor, and an inductor coupled in series between the switching node and the second input node, a transformer secondary circuit including a first transformer secondary winding and a second transformer secondary winding, the first and the second transformer secondary windings electrically between a first converter output and a second converter output, the transformer primary winding and the transformer secondary windings wound around at least a portion of a corresponding one of a transformer core in an infinity winding arrangement.