The concepts of state variable modeling have been applied to obtain a general circuit like model for the power PIN diode. The main aim of this paper is to demonstrate the feasibility of the state variable modeling approach for the PIN diode. From simplified semiconductor device differential equations, the model is built with the corresponding variational equation using an internal approximation. With a special choice of the decomposition functional basis of such internal approximation, it was possible to get efficient and reliable models for the reverse recovery. A simple model of three state variables that has only six parameters, most of which are technological, represented a major improvement in describing circuit/device waveforms during reverse recovery.