Single-Inductor Multiple-Output Buck Hybrid Converter with Simultaneous AC and DC Outputs for Multi-Coil Wireless Power Transfer Applications

Abstract

This paper proposes a non-isolated Single-Inductor Multiple-Output (SIMO) buck hybrid converter, which can simultaneously supply multiple independent AC and DC loads from a single DC input, by employing only one inductor in the power stage. Compared with the existing hybrid converter topologies, the proposed SIMO-based hybrid converter achieves a simplified circuit structure, smaller component count, fully independent power control of its outputs, and better scalability of a larger number of AC and DC outputs. A useful application of this hybrid converter is to drive multiple transmitting coils and USB charging ports in a multi-device Qi-compliant hybrid wireless charger. The experiment results show that the 6.8-W hardware prototype of a Single-Inductor Three-Output (SITO) buck hybrid converter produces two AC output voltages at 7.5 V (rms) each and one DC output voltage at 7.6 V, from a single 12 V DC input, without any noticeable cross-interference..