Digital Buck Converter with Adaptive Driving Circuit for Cascode Power MOS

In this paper, a fully integrated digitally controlled buck converter for 2.7V-4.2V Li-ion battery supplied application is proposed. The chip was manufactured by TSMC 0.18-$\mu \text{m}$ 1P6M standard CMOS process which has two different nominal operation voltage for MOSFET, 1.8V and 3.3V. In order to be used for 2.7V-4.2V Li-ion battery supplied application, cascode power MOS is applied in this work. Moreover, this work proposed a novel adaptive driving circuit to drive the cascode power MOS. With adaptive driving circuit, the efficiency of converter can be improved by lowering the effective conduction loss. The maximum improvement of efficiency is about 23%.