A low-ripple switched-capacitor DC-DC up converter for low-voltage applications

This paper describes a switched-capacitor type DC-DC up converter with high efficiency and low-ripple voltage. Identical charge pumps operating sequen tially in the proposed DC-DC converter reduce the magnitude of the ripple v oltage to 20% of the conventional converters. A new charge pump adopting PM OS switches near the output stage improves the power efficiency of the DC-D C converter by 10%. The proposed DC-DC converter is applied. as a test vehi cle. to a phase-locked loop circuit which is sensitive to power supply nois e. All circuits are fabricated and measured in a 0.65-mum CMOS process.