Switched-capacitor dc-dc converters with output inductive filter

Analysis and optimization of switched-capacitor (SC) dc-dc converters with a series inductive filter are developed. The steady-state output impedance of such SC resonant converters is calculated for a 21 conversion ratio. In addition, the necessary conditions for proper application of the output inductive filter are derived. The proposed optimization methodology applies numerical optimization to evaluate different loss components in order to find the optimal design point of highest conversion efficiency. This optimization method is verified through SPICE simulations on a 21 SC power stage in 65-nm CMOS process. © 2012 IEEE.