A 91% efficient 30V hybrid boost-SC converter based backlight LED driver in 180nm CMOS

Abstract

This paper presents a new hybrid boost converter architecture for improving the efficiency of LED drivers used in mobile applications. By cascading a low-switching frequency time-interleaved series-parallel SC-stage with an inductive boost converter, we facilitate the use of lower voltage rated switches, thus greatly reducing the switching losses. Charge-sharing losses of the SC stage are minimized by soft-charging flying capacitors with the inductor of the boost stage. Fabricated in 180nm BCD process, the prototype converter generates 30V output voltage from a Li-ion battery source and can provide a load current in the range of 0 to 100mA with an excellent peak power efficiency of 91.15% at 30mA. Compared to state-of-the-art designs, the proposed converter achieves a 3 % improvement in peak power efficiency.