Design and implementation of a high step-down interleaved DC-DC converter

Abstract

This paper proposes a novel nonisolated converter topology with high step-down conversion ratio for high current and low voltage application, such as voltage regulator modules (VRM). The proposed converter is based on several existed techniques such as coupled-inductor, switched capacitor and interleaved technique. Compared to a conventional two-phase buck converter. The novel converter is capable of delivering larger current to the output load by two coupled-inductors with interleaved technique. Futhermore, it features an inherent current sharing capability, which can balance the load current and reduce the output current ripple. Lastly, a converter with 48V input voltage, 1V output voltage and 30W output power is implemented to prove the feasibility of proposed converter. The highest efficiency is around 90.2% when operating at 3 W and the efficiency is 79.3% at full load.