MHz-Driven Snubberless Soft-Switching Current-Fed Multiresonant DC–DC Converter

A new multiresonant step-up dc–dc converter is proposed in this article, which is suitable for obtaining a high dc–dc voltage ratio with minimizing the counts of active and passive components. The proposed dc–dc converter features the snubberless zero current soft-switching (ZCS) commutation with megahertz (MHz) high-frequency driving of galliumnitride-high electron mobility transistor-based two-phase class-E inverters by adopting quasi resonance and dual parallel load resonance; multiresonant circuitry. The circuit configuration and operation principle are described together with the theory of switch-mode transitions and steady-state power transfer. A frequency-domain analysis is provided on the basis of the equivalent circuit, and the design guideline of multiresonant tanks is provided in details. The essential performances of the proposed dc–dc converter are demonstrated by experiment of a
$\rm {1}$
-
$\rm {\text{2}\,MHz}$
/
$\rm {\text{120}\,W}$
prototype; ZCS operations are confirmed over the wide range of load variations (
$\rm {40\%}$
–
$\rm {100\%}$
) with maximum efficiency
$\rm {91.3\%}$
at
$\rm {86.5\%}$
load, electro magnetic interference noise reduction
$\rm {29\%}$
–
$\rm {79\%}$
as compared to hard switching, and the voltage ratio 1.5 times higher than the nonmultiresonant topology, and less than
$\rm {1\%}$
low-current ripple factor in the dc inductor.