A Versatile DC-DC Converter Designed by Using Switched-Capacitor Techniques

Aimed at mobile applications such as backlighting applications, battery applications, etc., a switched-capacitor (SC) DC-DC converter which offers a (N - s + 1)/(N - s) x mode ((N = 1, 2, ...) and (s=0,1,2, ...)) as well as a step-down mode of operation is presented in this paper. Compared with the conventional versatile converters, the proposed converter can realize high efficiency and flexibility of output voltages. The validity of the proposed converter is confirmed by SPICE simulations and theoretical analyses. Concerning the power efficiency and the optimal duty factor, the confirmation result shows that the theoretical results correspond to the simulation results well. Furthermore, under the conditions where the input voltage V-in =3.7 V, the output load R-L = 30 Omega, and the output voltage V-out = 3.3 similar to 5.3V, the proposed converter can improve the power efficiency more than 20% from that of the conventional circuit.