Triple step-down DC-DC converters

Triple DC-DC power converters appear as a development of the double (quadratic) power converters. Compared to double DC-DC power converters, triple convertors make it possible to use much higher switching frequencies for the same minimum switch-conduction time. DC output/input, AC input-to-output and AC control-to-output small-signal transfer functions of the triple-buck (or double-buck+forward) power converter have been deduced and plotted against load current and frequency, in the operating mode with continuous currents in all inductors, for different values of the circuit components and parameters, taking into account circuit losses. Triple DC-DC power converters have large transfer function phase shifts, but, with properly staggered resonant frequencies of the three LC cells and using additional AC feedback loops, stable SMPSs may still be constructed from them, without drastically limiting error amplifier bandwidth.