A 28V-to-3.3V, 2 A, Fully Monolithic 3-Level Hybrid Converter in 130 nm HV-CMOS

This paper presents a fully monolithic 3-Level Hybrid Flying Capacitor (3LHFC) converter based on a 130 nm technology node. The design targets a 28V-to-3.3V, 2 A, step-down dc-dc converter. An analog phase-shift modulator keeps the flying capacitor under control, and a dedicated startup circuit brings the flying capacitor to its target value in cold-start conditions. Integration of the full power stage on chip operating at 1 MHz switching frequency results in high conversion efficiency and in the reduction of the external passive components. The presented 3LHFC converter has been validated in silicon. Experimental results are shown and compared with the current state of the art.