Anticipatory Control of Voltage Regulator Modules

Fast load transient response and tight regulation are two strict specifications of voltage regulator module (VRM) design for powering desktop and mobile microprocessors. This paper presents a VRM topology for microprocessor applications. In this topology, instead of conventional bulky capacitors, smallmetal-oxide-semiconductor field-effect transistors(MOSFETs) utilized to provide fast transient requirements of the system. VRM topology basedon anticipatory controltightly maintains output voltage of the converter within the required output voltage ripple band during transients. In anticipatory control, since there is no need to instantaneous changes in the inductor current, therefore, the dynamic response of the converter to the load changes is ultra-fast. A 12/1.5-V, 25-A, and 300 kHz VRM, based on anticipatory control is designed, built and tested. The proposed topology is validated with detailed simulation and a hardware prototype.