A novel digital controller is presented in this paper that significantly improves the dynamic response of a voltage regulator module (VRM). The controller uses a digital linear scheme during steady-state operation and an innovative non-linear scheme during transient load conditions. The proposed non-linear controller accurately calculates the optimal response to an arbitrary load step variation. This paper demonstrates the design procedure of a VRM using the proposed controller. Since the response to the load variation is predictable, an engineer is able to design (without iteration) a VRM that is guaranteed to meet a set of dynamic response criteria (voltage deviation, recovery time).