Monolithic cascade device in low power converter applications with wide range input voltage

An improved converter for low power and wide range input voltage, which is particularly suitable for auxiliary uses in three-phase grid of industrial applications, is studied. A flyback quasi-resonant topology has been chosen, which offers the good characteristics of high voltage operations and good efficiency. A comparison is performed among available kinds of semiconductor devices with good peculiarities for the specific topic. In particular the analysis focuses on MOSFET and cascode devices. The latter component shows good characteristics in this specific application of high voltage operations at high switching frequency and low power. The converter design is described with a particular attention to the crucial instances of switching and conduction losses and the thermal dissipation. Moreover the quasi-resonant operation mode has been exploited in order to improve the effectiveness of the solution adopted. The zero voltage operation is obtained by a gate driver chip specifically designed to build offline quasi-resonant zero voltage switching in flyback converters. Finally, several experimental tests are considered and specifically described