Finding the steady state of high-Q circuits with proper initial values of the transient analysis

A simple way to find the steady state is long-time transient simulation run, but for high-Q-circuits his is often not practicable. Additionally, a criterion has to be determined in order to be sure of reaching the steady state. This problems of the transient analysis of high-Q-circuits have already been addressed in the PSPICE-Manual. These circuits require setting up the time step manually because they are extremely sensitive to inaccuracies in integrating the differential equation near resonance. To overcome this extremely long simulation time, exact initial values must be calculated before running the transient analysis. The method of finding these values will be explained using a simple crystal oscillator as an example.