Interleaved switched-capacitor converters with adaptive control

The switched-capacitor converters are ideal switching-mode power supplies for consumers portable electronic devices due to their light weight, small size, and high power density. However, they suffer from a discontinuous input current waveform with large di/dt, which leads to significant electromagnetic interference (EMI) emission. This paper proposes a configuration of switched-capacitor converters connected in parallel, with their inputs and outputs interleaved and adaptively controlled. The interleaving operation is performed by using an original type of control in which both the capacitors' charging time T_on and switching frequency are adjusted to get the line and load regulation. It is shown that, for a given range of variation of the supply voltage and load, there always exists a solution [T_on, T_S] assuring both output voltage regulation and a perfect interleaving. Experimental results are provided to validate the feasibility of the proposed scheme. Precise interleaving and good line and load regulation are maintained for all the designated range, including the transient times.