An integrated SIDO boost power converter with adaptive freewheel switching technique

Abstract

This paper presents a single-inductor dual-output (SIDO) boost DC-DC converter with an adaptive freewheel switching technique. Due to the adoption of freewheel switching duration averaging, the optimal freewheel durations in each phase of the SIDO converter are acquired within one switching cycle. The optimal freewheel switching duration improves the efficiency of the SIDO converter, especially during unbalanced load conditions, by reducing the conduction losses due to the lossy freewheel switch. The proposed controller also accelerates the freewheel switching current adjustment process during the load transient periods. The proposed converter, operating in the pseudo-continuous conduction mode (PCCM), has been verified through fully transistor-based HSPICE simulation results, with a 130-nm CMOS process. It achieves a maximum efficiency of 90.1%, at an output power of 430 mW and a switching frequency of 500 kHz. For a load change from 100 mA to 50 mA, the proposed technique reduces the conduction losses during the freewheel switching duration by 99.52%, compared with the traditional methods.