Output characteristics in the discontinuous reactor current mode of the zero-voltage switching DC-DC converter

It is often observed that the switching frequency in the zero-voltage switching DC-DC converter becomes extremely low when the load current increases and/or when the input voltage decreases. This lowering deteriorates the advantage of the high frequency in designing the energy-storage elements of the DC-DC converter. The output characteristics of the zero-voltage switching DC-DC converter operating in the discontinuous reactor current mode are analyzed. It is shown that there exists a useful discontinuous mode in which the variation of the switching frequency can be restricted within +or-5% when the output voltage can be regulated for the load change from no load to full load or for +or-15% change of the input voltage. The voltage stress of the switch can be sufficiently suppressed compared with that in the continuous reactor current mode.<
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