In this study, a control technique combining the pulse amplitude modulation (PAM) and the pulse width modulation (PWM) is presented to minimize the output voltage ripple of the proposed converter. The proposed converter is a two-stage structure. The first stage, used to adjust the input voltage of the second stage, is an active clamp buck-boost converter, and the second stage, used to reduce the output voltage ripple, is a two-phase interleaved buck converter with an active clamp based on only one resonant circuit. Furthermore, the output voltage ripple can be cancelled when the two-phase interleaved buck converter operates under the condition of individual duty cycles of 50% with a phase shift of 180o. Moreover, both the first stage and second stage converters can achieve zero voltage switching (ZVS). Therefore, compared with hard switching control, the efficiency can be improved. Above all, the number of phases can be extended. Finally, the operating principles and experimental results are provided to verify the performance of the proposed converter.