A new transformer integrated with additional resonant inductor is proposed in this paper. By winding on outer side of transformer, the proposed transformer can implement the additional resonant inductor without extra magnetic component. As a result, it can reduce cost and core loss due to the additional resonant inductor. In addition, it can adopt primary clamping diodes to reduce the voltage ringing of secondary rectifiers, although the additional resonant inductor and the transformer are integrated physically. Experimental result of 1200 W (12 V, 100 A) prototype shows that the phase-shift full-bridge converter incorporated with proposed transformer can achieve high efficiency and low cost.