A High Step-Down Two-Phase Buck Converter with Two Winding Inductors

Kimihiro NISHIJIMA  Hiroyuki KAWAGOE  Satoshi TOMIOKA  

B - Abstracts of IEICE TRANSACTIONS on Communications (Japanese Edition)   Vol.J101-B   No.3   pp.233-244
Publication Date: 2018/03/01
Online ISSN: 1881-0209
Type of Manuscript: PAPER
multi-phase,  buck-converter,  tapped-inductor,  current-doubler,  MPU,  FPGA,  

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As a high step-down non-isolated DC-DC converter, which is suitable for digital IC such as MPU and FPGA, we introduce a proposed two-phase buck converter with two cores and four windings. In the similar way as that of a typical half bridge converter, a capacitor is added to the primary side for dividing the input source voltage into one half. The voltage conversion ratio is given as one fourth of the duty cycle with unity turns ratio of each transformer. The output capacitor ripple and the switching losses are well reduced. Switching elements with low voltage withstand are usable and zero current switching (ZCS) operation is realized. The currents in each phase are balanced automatically without any current sensing methods. Experimental prototypes with simple tapped-inductor construction verify as compared to the conventional two-phase buck converter.