DC-DC converter having VFM mode in which inductor current increases and switching frequency decreases

摘要

A non-isolated DC-DC converter that converts a voltage input to an input terminal to output a constant output voltage to a load terminal while switching control mode between a PWM mode and a VFM mode depending on a current output to the load terminal. The DC-DC converter includes an inductor, a switching circuit, and a control circuit. The inductor stores electric energy for supply to the load terminal. The switching circuit switches on and off current flow at a switching frequency to alternately charge and discharge the inductor. The control circuit increases an electric current flowing to the load terminal through the inductor per one operational cycle as the switching frequency decreases during VFM control mode operation.