A Novel Control Scheme for MHz Range Interleaved Multiphase Resonant VRM

Abstract

The interleaved multiphase resonant topology is very attractive for VRM since faster transient response and higher power density are required to meet the increasingly high demands for speed and efficiency of the next generation microprocessors. However, to solve the control strategy issue for the interleaved multiphase resonant VRM, a novel control scheme was proposed. The driving signals of this scheme can automatically track the frequency of a central main signal, while maintains a locked shifted-phase angle to provide each phase's driving signal under all conditions, with a very simple circuit configuration and effective cost. In addition, the proposed scheme has a good ability of expanding to an n-phases interleaved VRM conveniently. Then the detail design process was also presented. A prototype was built and the results confirmed the validity and applicability of the proposed control scheme, while the highest frequency reaches to 1.1 MHz. Therefore, the merits of the proposed scheme can endow interleaved multiphase resonant VRM be more suitable for the next generation microprocessors.