Optimal design to maximize efficiency of single-inductor multiple-output buck converters in discontinuous conduction mode for IoT applications

摘要

To clarify the design guide of single-inductor multiple-output (SIMO) buck converters in discontinuous conduction mode (DCM) targeted for small-size and low-power IoT applications, equations of optimal design parameters (transistor size, inductance, and switching frequency) to maximize the power conversion efficiency are derived for the first time. The analytical optimal designs are verified with SPICE simulations. The maximum efficiency of SIMO DCM buck converters is lower than that of conventional single-inductor single-output (SISO) DCM buck converters, because the power loss due to the energy distribution switches is added. The efficiency degradation is analytically explained for the first time.