Dc-dc buck converter

A DC-DC buck converter comprising:

• a buck conversion circuit including a switching circuit and a LC circuit, the switching circuit includes a plurality of upper switching elements and a plurality of lower switching elements, the upper switching elements are electrically connected to the lower switching elements, the LC circuit is electrically connected to the switching circuit and configured to output an output voltage;
• a PWM control circuit coupled to the buck conversion circuit, the PWM control circuit is configured to generate a control signal which is provided to control the upper and lower switching elements;
• and
• a light-load control circuit coupled to the PWM control circuit and the buck conversion circuit, the light-load control circuit is configured to receive the output voltage, the control signal, and a light-load threshold value and determine whether the DC-DC buck converter is in a light load state according to the output voltage and the light-load threshold value, wherein when the DC-DC buck converter is in the light load state, the light-load circuit is configured to turn off at least one of the upper switching elements and at least one of the lower switching elements so as to inhibit the at least one turned-off upper and at least one turned-off lower switching elements from operating in buck conversion.