Conventional off-chip or single-stage on-chip converter will fail to meet the demand for different supply voltage domains for various functional blocks/cores in traditional or future multi-/many-core system-on-a-chips (SOCS). In this paper, a hybrid two-stage voltage regulation scheme is proposed, where the first stage consists of a switching voltage regulator located off-chip, and the second stage consists of a tree structure of linear regulators located on the chip. This approach proves to be efficient, simple and less costly compared to other options that offer total on-chip integration of a switching regulators. The difficulties and limitations of on-chip switching regulator have been analyzed. For the tree structure of on-chip linear regulators two different architectures (cascaded and parallel) have been proposed. It is demonstrated that a cascaded tree of linear regulators is a better solution than a parallel tree structure from performance point of view.