An 87.2%-peak efficiency 4.1 W-output power switchedcapacitor 3-level inverting buck-boost dc-dc converter

In recent years, active-matrix organic light-emitting diode (AMOLED) technology has been widely employed in various display applications, thanks to its higher image quality and lower power consumption. With the spread of AMOLED displays, the need for regulated negative power supplies and, hence, high-efficiency inverting buck-boost (IBB) dc-dc converters to power the pixels has arisen [1] –[3]. This paper proposes a novel IBB hybrid structure, which combines a switched-capacitor (SC) and a 3-level (3L) architecture in order to lower the inductor current and avoid exceeding its saturation limit, while maintaining high efficiency.