Abstract: This paper presents a width controller, a dead time controller, a discontinuous current mode (DCM) controller and a frequency skipping modulation (FSM) controller for a high frequency high efficiency buck DC–DC converter. To improve the efficiency over a wide load range, especially at high switching frequency, the dead time controller and width controller are applied to enhance the high load efficiency, while the DCM controller and FSM controller are proposed to increase the light load efficiency. The proposed DC–DC converter controllers have been designed and fabricated in the Chartered 0.35 μ m CMOS process, and the measured results show that the efficiency of the buck DC–DC converter is above 80% over a wide load current range from 8 to 570 mA, and the peak efficiency is 86% at 10 MHz switching frequency.

Key words: buck DC–DC converter, dead time controller, discontinuous current mode, width controller, frequency skipping modulation