Isolation issues in smart power integrated circuits

This paper analyses a major problem inherent to smart power integrated circuits employed with inductive loads, i.e. the rejection of carriers inside the substrate during switching off. Firstly, the physical mechanisms involved are presented as well as some solutions to minimize the perturbations inside the common substrate of the integrated circuit. Secondly, use of dielectrically isolated substrate to avoid the problem is critically assessed and leads to the conclusion that DI is not a perfect solution regarding the thermal dissipation and the switching speed.