The system consisting of several cascade connected electrical circuits is presented in this paper. Considering the system structure and the fact that the tunnel diodes have nonlinear characteristics, one of the properties of this system is the possibility of the chaos appearance. Necessary conditions and sufficient condition for the chaos appearance in the nonlinear cascade connected systems are given and analyzed, too. The results are confirmed by bifurcation and escape-time diagrams simulation. (C) 2016 Elsevier Ltd. All rights reserved.