A novel single switch two diodes wide conversion ratio step down/up converter is presented. The proposed converter is derived from the conventional Single Ended Primary Inductor Converter (SEPIC) topology and it can operate into a capacitor-diode voltage multiplier, which offers simple structure, reduced electromagnetic interference (EMI), and reduced semiconductors voltage stress. The main advantages of the proposed converter are the continuous output current, higher voltage conversion ratio, and near zero input/output current ripples compared with the conventional SEPIC converter. The principle of operation and comparison with the conventional SEPIC converter are presented. The performance of the proposed converter is verified through computer-aided simulations and experimental results.