A Switched-Capacitor DC-DC Converter with Pseudo-Continuous Output Regulation using a Three-Stage Switchable Opamp

SC dc-dc converters with continuous-output regulation (COR) for delivering hundred-milliwatt output power have been recently reported [1,2]. The control schemes of these converters can reduce both input-current ripple [1] and output-voltage ripple [2]. These converters, however, require one extra power transistor cascaded either in front of [1] or behind [2] the power stage for output regulation. The additional power transistor increases the chip area of the converter. This paper proposes a new control scheme for the regulated SC dc-dc converter to achieve COR without using any additional power transistor. Moreover, a three-stage switchable opamp in the proposed control is developed to improve both load-transient response and light-load power efficiency of the converter