Small-Signal Modeling and Cross-Regulation Suppressing for Current-Mode Controlled Single-Inductor Dual-Output DC–DC Converters

Abstract

A current-mode control, which can be applied to three basic single-inductor dual-output (SIDO) dc-dc converters to suppress cross-regulation, is proposed in this article. The control circuits and operation principles under different inductor current trends and switch sequences are introduced. The SIDO boost converter operating in continuous conduction mode (CCM) is taken as an example to establish the complete and accurate small-signal model in detail. Based on which, the optimal compensators design are presented in this article. And then, the cross-regulation and transient performance are analyzed via Bode plots, and the SIMPLIS simulation results are presented to validate the small signal model. In addition, the stability condition for current mode controlled CCM SIDO boost converter is studied by using Routh-Hurwitz criterion. Finally, experimental results verify the correctness of the theoretical analysis. The research results indicate that the proposed current-mode control significantly reduces the cross-regulation of SIDO dc-dc converter compared with the existing control schemes.