In an integrated transformer assembly, a common coil member has a first portion alternately wound, for each one electromagnetic turn, around the first core member and around the second core member. The first portion of the common primary coil member wound around the first core member is magnetically linked to the first magnetic path thereof so as to constitute a first primary coil. The first portion of the common primary coil member wound around the second core member is magnetically linked to the second magnetic path thereof so as to constitute a second primary coil. The first and second primary coils are connected in series. A secondary coil member has first and second secondary coils. The first and second secondary coils are arranged to be magnetically linked to the first and second primary coils of the common primary coil member, respectively.