A hybrid converter for improving efficiency at light load region

In order to reduce power consumption of electronic equipment in stand-by mode, idle-mode and sleep-mode, a simple efficiency improvement technique for switching regulator in light load region is proposed. During the light load, small switching elements in a MOSFET driver circuit are used instead of switching elements in a main regulator circuit to reduce switching and driving losses. Of course, during the load heavier than light load (normal load), the MOSFET driver drives the switching elements in the main regulator circuit. The efficiency of a 1.8V/7A prototype buck converter is improved from 60% to 85% by using the proposed technique.