Pulse Skipping Switching mode: a case study of Efficiency Improvement on a switched-capacitor DC-DC step-up converter IC

A power efficiency study of a full-custom two-phase voltage doubler based switched-capacitor DC-DC step-up converter IC is presented in this paper. The study is focused on the global IC power consumption but also on the particular power consumption of the different circuits that form the whole design because besides including the voltage doubler architecture, additional circuits like power-up circuits, low-power level shifters, digital control logic and a pulse skipping frequency regulator have been included in the final IC design for having a robust, efficient and fully working step-up converter. Two switching modes have been implemented in the designed IC: normal mode and pulse skipping mode. Simulated results of the IC´s power consumption show a remarkable efficiency improvement, especially at lighter loads, when pulse skipping switching mode is applied. The proposed design has been implemented using the high-voltage I²T100 0.7mu technology from AMI semiconductor and has been tested successfully