With the behavioral models of Class-E switching-mode circuits, we can simulate the steady state behaviors of original circuits efficiently. However, if the dynamical systems, which approximate the behaviors of the original circuits, include impulse modes, the behavioral models cannot be easily obtained. In this paper, we show that the behavioral models are given by using Weierstrass canonical form, even if impulse modes happen. Since the proposed method is quite general, this procedures would be widely applied to behavioral modeling of various kinds of power converters. We demonstrate effectiveness of the proposed models with some examples.