Control of DC-DC converter having low side and high side switches

摘要

A DC-DC converter is operable so that the low side supply switch 20 may be inhibited from turning on in a cycle following the high side supply switch 10 turning off. Turn on of the low side switch is inhibited if the time between turn off of the high side switch and the inductor L current reaching zero is less than a predetermined from going negative, which would reduce the efficiency of the converter. When turn on of the low side switch is inhibited the inductor current flows through a parallel path, such as a parasitic body diode associated with the low side switch, which allows current flow in one direction only.