A three-level buck converter and digital controller for improving load transient response

A method for improving heavy-to-light load transient response in low-power switch-mode power supplies is presented in this paper. It relies on the utilization of a 3-level 5-switch buck converter and a digital controller with an extended duty ratio control value. The method is experimentally verified with a 6 V to 1.3 V, 400 kHz, 8 W digitally controlled system showing 3 times faster response than that of a conventional buck.