Stability analysis and experimental validation of the supercapacitor-assisted low-dropout regulator

Abstract

The supercapacitor-assisted low-dropout (SCALDO) regulator is a unique new design approach to develop high efficiency, high current and low noise DC–DC converters, where a supercapacitor (SC) is used in the series path of a low dropout (LDO) regulator to act as a lossless voltage dropper. In the published literature, there has been much discussion about the stability of an LDO regulator, where different approaches are applied to frequency compensate depending on the LDO architecture. Given the case that the SCALDO technique is a combination of an LDO regulator and an SC, this study presents an analysis and experimental validation of the stability, based on a 12–5 V SCALDO prototype, proving that the effect of the SC energy recovery method does not make the overall regulator carry a stability issue in general.