32.5 A Scalable and PCB-Friendly Daisy-Chain Approach to Parallelize LDO Regulators with 2.613% Current-Sharing Accuracy Using Dynamic Element Matching for Integrated Current Sensing

A single low-dropout regulator (LDO) for high output current applications presents a challenge for chip-level thermal management and also tends to be inefficient. Straightforward parallelizing of LOOs to increase output current is a flawed approach since subtle variations between devices even with the state-of-the-art manufacturing techniques can cause one of the LDOs to take over the maximum current, and thus enter current limit or thermal shutdown leading to instability and loss of regulation. Parallelizing regulators [1]-[6] to share the high output current equally across each regulator while preserving regulation and stability and to spread the dissipated heat uniformly is thus a challenging design problem.