Unaffected Dynamic Performance of Coupled SIDO Converters Due to Phase Shift

Single input multiple outputs (SIMO) DC-DC converters have gained more attention in the application of portable devices, where different regulated supply voltages are required. This paper focuses on single input dual output dc-dc converter with a coupled inductor and is denoted as CI-SIDO. Phase shift in gate pulses is a PWM method widely used in the DC-DC converter. Phase shifting in CI-SIDO converters has benefits of reduced current ripples. However, it leads to a change in the operation of the converter and can degrade the dynamic performance of the converter. This paper investigates the effect of phase shift on the dynamic performance of CI-SIDO converter. To do so, small signal modeling of three types of CI-SIDO topologies, i.e., CI-SIDO buck, CI-SIDO boost and CI-SIDO boost-buck converter is carried out using the state-space averaging method. More importantly, it is observed that the phase shift does not affect the averaged small signal model, which means the dynamic performance of CI-SIDO converter remains unaffected by a phase shift in gate pulses. Simulation results confirm that the dynamic performance of CI-SIDO remains unaffected due to phase shift in gate pulses.