To properly select a device for a new application, it is usually best to first identify the datasheet parameters required. It is sometimes useful to visualize where the application lies with respect to a V-I curve. The green area shows the normal operating voltages of the system to be protected. VDRM, or the peak off-state voltage parameter of the SIDACtor, must be above all of the green voltages. The red area represents voltages that will damage the protected system. VS, or the switching voltage of the SIDACtor, must be below all of the red voltages. So the resulting yellow area is the range of voltage where the SIDACtor device maybe active. Once the voltages are determined, select the correct holding current and surge withstand capability. Next the capacitance and linearity issues need to be addressed. With this data, designers should be able to select an appropriate configuration for the application.