Improving Loading and Unloading Transient Response of a Voltage Regulator Module Using a Load-Side Auxiliary Gyrator Circuit

This paper introduces a new voltage regulator module (VRM) that merges a highly efficient switched-inductor converter as the main unit with a load-side switched-capacitor-based converter to assist during load transient events. The resulting hybrid-VRM exhibits improved dynamic performance for both loading and unloading transient events, while maintaining a compact design with reduced output capacitance and lower components stress. The hybrid controller that has been developed allows operation that is based on output voltage measurement alone, further reducing the circuit complexity. A power processing efficiency analysis that has been carried out shows efficiency improvement in favor of the hybrid-VRM when compared to time-optimal control under varying load conditions. The operation of the VRM is verified on a 20-W, 12V-to-1.5-V prototype with peak power conversion efficiency of 93%, demonstrating near-ideal transient recovery.