Excitation Mode (Excitation menu)

The excitation mode line can be set to Equilibrium, Steady State, or Transient. The choice determines the final state the solution will achieve before stopping. The solution will always proceed by solving first for Equilibrium, then Steady State, then Transient.

If the Mode is Transient, it is necessary to supply additional details for controlling the time dependence of the solution. The Step Size is the elapsed time between time steps. Setting this value too small may cause convergence problems. Large values (e.g. 1 second or more) can be used to simulate the quasi-static response of the device to a swept excitation. Examples include current versus voltage and spectral response versus wavelength. The initial time step, which immediately precedes t=0, can be set to a different value from the remaining steps. Setting this value small permits the simulation of an abrupt change in excitation at time t=0. The entry for Number of Time Steps is the number of time steps of duration Time Step Size that are desired. The total duration of the transient will be the product of these two values.