Traditionally, in the microprocessor industry, multiphase voltage regulators (VRs) are implemented with discrete non-coupled inductors in each phase. Recently, Trans-Inductor Voltage Regulators (TLVR) have been proposed in the literature where the discrete inductors are replaced with transformers with all the secondary sides of transformers connected in series with a compensating inductor. Although TLVR solutions have been widely implemented in the industry, still there is a lack of critical analysis and comparative study with regards to the conventional solutions. Thus, an in-depth comparative study and analysis is required to enable the microprocessor industry to replace the conventional solutions with TLVRs and understand the implications from various aspects of design, cost & limitations perspectives. This article aims to provide a holistic analytical and experimental comparative study over discrete (conventional) multiphase VRs versus TLVRs from various viewpoints including, design, performance (steady state and transient), bandwidth, efficiency, control complexity, PCB footprint, and cost perspectives.
