Methods and apparatus for full gate drive of multilevel DC-DC converter with full duty cycle operation

摘要

Methods and apparatus for bootstrap capacitor sharing in multilevel DC-DC converters are disclosed. In one example, a bootstrap capacitor voltage of the bootstrap capacitor can be alternately shared between respective control gates of a first high side primary switch and a central high side primary switch of the multilevel DC-DC converter at different times during a duty cycle of the multilevel DC-DC converter. In another example, the bootstrap capacitor voltage can be transferred to drive respective control gates of the first and central high side primary switches and can ensure full gate drive of the first and central high side primary switches to avoid channel resistance degradation thereof, even when the multilevel DC-DC converter is operated in a substantially full duty cycle mode.