A completely smooth transition Buck-Boost Converter with Continuity-Mode (CM) Technique for only using 2 switches in whole battery life

In this paper, a high efficiency and completely smooth transition between buck and boost mode, non-inverting Buck-Boost Converter with Continuity-Mode (CM) Technique is presented. The proposed continuity mode technique provides smooth transition and minimizes the switching and conduction losses better than conventional buffer mode. It just like buck or boost mode, the number of switches are used in one switching cycle is reduced from four to two and the inductor current is reduced to close to the value of load current. The results show the problem of pulse skipping in mode transition region is removed and without expense any unnecessary power losses. The dc output voltage is regulated on 3.3V in whole decreasing battery life. The output voltage ripple is reduced in transition region due to without pulse skipping and approximate to zero due to the duty cycle is close to almost 100% when the input voltage equal to output voltage.