Modeling and analysis of digital linear dropout regulators with adaptive control for high efficiency under wide dynamic range digital loads

Discrete time digital linear regulators, including low dropout regulators (LDOs) have become competitive in muti-Vcc digital systems for fine-grained spatio-temporal voltage regulation and distribution. However, wide dynamic current range of the digital load circuits poses serious problems in maintaining stability and high efficiency at all corners. In this paper we present a control model for discrete time LDOs and demonstrate how online adaptive control can be employed for consistent performance and high efficiency across the load current range.