Steady state analysis of two stage converter combined with coupling capacitor

In order to have a power supply with high voltage conversion ratio for low voltage and high current digital ICs, this paper presents a new two stage converter combined with a coupling capacitor. A bottom switch of the first stage is removed and the switching nodes of the first stage and the second stage are coupled together by the coupling capacitor. The steady state analysis is performed and the voltage conversion ratio is derived which is found to be larger than single stage converter. A 12 V to 1 V prototype converter is implemented to confirm the analysis. The higher power efficiency compared with conventional converter is achieved.