A high-efficiency DC-DC buck converter for sub-3×VDD power supply

This paper presents a DC-DC step-down converter, which can accommodate the range of input voltage from VDD to sub-3×VDD voltage. By utilizing stacked power MOSFETs, a voltage level converter, a detector and a controller, the proposed design is realized by a typical 1P6M 0.18 μm CMOS process without using any high voltage process to resolve gate-oxide reliability and leakage current problems. The core area is less than 0.184 mm², while the VDD range is up to 5 V. Since the internal reference voltage is 1.0 V, it can increase the output regulation range. The proposed design attains very high conversion efficiency to prolong the life time of battery-based power supply. Therefore, it can be integrated in a system chip to provide multiple supply voltage sources.