This paper presents the double-coupled current-fed push-pull dc/dc converter which operates from 0 to 100% of duty cycle. One primary winding in the transformer, low rms current in the output capacitor, double switching frequency in the input and the output filter, null ripple current in the input and in the output for 50% of duty cycle, are some characteristics of this new topology. These allow reductions of size and weight of the components. Qualitative and quantitative analysis are presented, in which the simplified model of the inductor coupled and the ideal model of the transformer are used. Finally, experimental results of a prototype are shown for the converter operating with a duty cycle higher or lower than 50%. The possible applications of this topology are automotive, electric power generation such as fuel cells, solar and wind. © 2009 IEEE.