Floating Reduced Duty Cycle Step-Down Converter

Alongside the interleaved concept, the floating two-stage converter concept can be applied to increase the power of a converter. Two converters can be connected in parallel at the input and in series at the output. Using two non-inverting step-down converters with a limited duty cycle, the output voltage of the complete converter is the sum of the output voltages of the two stages reduced by the input voltage. The load current of each stage is equal to the load current of the complete converter. It is useful to build such a converter symmetrically. The converter is treated in the steady state, and large and small signal models are derived using one converter stage which is loaded with the output current of the complete converter in the case of a resistive load. The inrush is studied when the converter is applied to a stable input voltage. To avoid the inrush, a pre-stage is connected in front of the converter. The voltage and the current stress of the semiconductor components are investigated. The transfer functions are calculated and Bode plots are shown for an operating point.