Low-cost Compact Approach to Reinforced Isolated Drive for LLC Converters

Abstract

Modern power converters are expected to have high efficiency and features like datalogging. This typically results in a design with a digital controller implemented on the secondary side, which means having to drive transistors across the galvanic isolation barrier. The most common approaches are a) Bulky magnetic drive with many turns of triple-isolated wire; b) Compact but costly coreless transformer ICs that also require local powering; This work presents an alternative approach, which optimizes size and cost without compromising performance in traditional applications, intended for driving a complementary pair of MOSFETs like in Half-Bridge LLC converters.