A Quasi-Single-Stage 48 V-to-0.8 V Voltage Regulator Module Based On Half-Bridge Current Doubler With Zero Bias TLVR

This work introduces a quasi-single-stage 48 V, 350 A VRM voltage regulator module (VRM). A single module combines a four-phase half-bridge current doubler (HB-CD) and a single-phase non-isolated buck converter. The former performs the direct conversion from the 48 V, while the latter from an intermediate bus voltage (IBV) of 5 V. Phase coupling is realized thanks to TLVR, which the buck converter actively supplies to drive the output, achieving zero DC-bias flux in the HB-CD integrated magnetic (ZB-TLVR). Optionally, buck power stages can be further coupled by a conventional, second level TLVR (Cascaded TLVR). A system demonstrator for 48 V/0.8 V has been built. With multifrequency, cascaded ZB-TLVR operation, the converter is capable of fast transient response in an overall efficient (90% peak, up to 84.7% TDC) solution.