A transformer includes a closed loop core having a first leg and a second leg. The transformer also includes a first primary winding surrounding the first and second legs, a second primary winding surrounding the first and second legs, and first and second secondary windings surrounding the first and second legs, respectively, and disposed between the first and second primary windings. A first turn of the first and second secondary windings are disposed on a first interlayer winding layer, and other turns of the first and second secondary windings are disposed on a first layer that is further from the first primary winding than the first interlayer winding layer.