Design of ultra-wide-load, high-efficient DC-DC buck converters

The paper presents the design of a current-mode control DC-DC buck converter with pulse-width modulation (PWM) mode. The converter achieves a current load ranged from 50 mA to 500 mA over 90% efficiency, and the maximum power efficiency is 95.6%, where the circuit was simulated with the TSMC 0.35 um CMOS process. In order to achieve ultra-wide-load high efficiency, this paper implements with two PMOS transistors as switches. Results show that the converter achieves above 90% efficiency at the range from 30 mA to 1200 mA with a maximum efficiency of 96.36%. Results show that, with the additional switch transistor, the current load range is expanded more than double. With two PMOS transistors, the proposed converter can also achieve 3 different load ranges so that it can be programmed for the applications which are operated at those three different load ranges.