The operation of switched-capacitor (SC) DC-AC converter are as follows. (1) The DC input voltage is converted into a stair wave by SC converter. (2) The stairs wave is smoothed by a regulator. (3) The sinusoidal AC output is taken out using a full bridge. The power efficiency is different depending on the number of the steps of the stairs wave. Then, the purpose of this paper is to load the expression of the relation between the number of the steps and the power efficiency.
