Figure 2-2 shows the block diagram and the equivalent circuit of the dual-switch architecture. The key difference between dual-switch architecture and basic architecture is the use of two switches between Line and Neutral.

The basic working principle is to close these two switches alternately, forming two different equivalent circuits. The two equivalent circuits correspond to two different equations, thus solving for the values of the two insulation resistances, R_isoL and R_isoN. TIDA-010232 is a reference design based on this architecture.