Switches made simple with voltage inverting converter

Switching power supplies that include a monolithic integrated specialized circuit the design is based on are called today "switches made simple". This paper is one of them and it presents two switching power supplies with MC34063 and muA78S40 monolithic switching regulator subsystems that control a DC-DC step up - down converter. General description of MC34063 and muA78S40 operation modes, mathematical design and PSpice under ORCAD simulation of the whole switching power supply, a numerical example and the practical implementation are included. Some practical considerations are also presented.