Switching and conduction loss analysis of buck converters operating in DCM-only scenarios

Formulas for estimating the most critical switching and conduction losses in low-power buck converters operating in DCM-only schemes with light loads are derived. The derivation takes into account the actual behavior of the converter in DCM instead of relying on commonly-used approximations that are based on CCM operation. This leads to more accurate estimation of losses. The formulas can be used by designers to correctly optimize the sizes of the power FETs and develop realistic budgets for parasitics so as to achieve the best possible efficiency.