DCM control scheme for single-inductor multiple-output DC-DC converter with no cross-regulation

Abstract

Single-inductor multiple-output (SIMO) switching DC-DC power converter architecture is a cost-effective alternative to multiple individual switching power converters solution in many power distribution system applications where multiple voltage rails are required. However, with multiple output voltage rails coupled to the same switching node, the SIMO power converters suffer from cross regulation among the multiple outputs, which complicates the closed-loop controller design of the SIMO converter and degrades performance. In this paper, an inductor continues conduction mode (DCM) power-multiplexed control (PM-DCM control) scheme is proposed aiming to completely decouple the multiple outputs from one another. The proposed PM-DCM control scheme results in eliminating the cross regulation among the multiple outputs while maintaining desired voltage regulation performance for each output under both steady-state and dynamic operations. Moreover, low-cost microcontroller or analog circuitries can be used to implement the proposed controller. Simulation and preliminary experimental results are given to verify the feasibility and advantages of the proposed concept.