Instantaneous Power Consuming Level Shifter for Improving Power Conversion Efficiency of Buck Converter

Abstract

An instantaneous power consuming level shifter is presented in this paper to increase the DC converter efficiency. The level shifter is used in a high-side power switch driver to remove the external capacitor which is used in bootstrap technique. The level shifter consumes power only during the transition period. A delay cell is used to turn the level shifter off to reduce the power consumption period. An output voltage detector is added to turn the level shifter off even before the delay time. An asynchronous discontinuous conduction mode buck converter is designed to verify the performance of the level shifter. Simulation results show that the power consumption of the proposed level shifter decreased by 66%, while the converter efficiency increased by the maximum of 9% compared to results obtained for a conventional level shifter. The converter is fabricated using the TSMC 0.18-μm BCD process and it operates within an input range of 2-5 V when the current varies from 400 μA to 18 mA and delivers an output voltage of 1.8 V.