A Two-Phase Four-Parallel Coupled-Inductor Converter with Voltage Dividing Capacitors

Kimihiro NISHIJIMA  

Publication
B - Abstracts of IEICE TRANSACTIONS on Communications (Japanese Edition)   Vol.J101-B   No.2   pp.179-186
Publication Date: 2018/02/01
Online ISSN: 1881-0209
DOI: 
Type of Manuscript: PAPER
Category: 
Keyword: 
multi-phase,  buck converter,  VRM,  low voltage high current,  CPU,  coupled-inductor,  

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Summary: 
In this paper, a two-phase four-parallel coupled-inductor converter with voltage dividing capacitors is proposed. This converter has a very high step-down characteristic as Vo/Vi = D/4. The switching loss and noise of all switching elements are sufficiently reduced because the drain-source voltages at switching periods are reduced to a quarter of the input source voltage. Low withstand voltage MOSFETs with low on resistance and low Qg (total gate charge) characteristics are possible to use for all the switching elements because the maximum voltage stresses of the main switches and the synchronous rectifier switches are reduced to a half and a quarter of the input source voltage respectively. Further, the blanch currents flowed through the paralleled converters are automatically and mostly balanced without the current detection and balance control. Moreover, the voltage divided capacitors are also useful for protecting the load from overvoltage when the main switches are short-circuited. The above fine characteristics are simply achieved with three additional capacitors.