The TMUX7411F, TMUX7412F, and TMUX7413F detect overvoltage inputs by comparing the voltage on a source pin (Sx) with the supplies (V_DD and V_SS). A signal is considered overvoltage if it exceeds the supply voltages by the threshold voltage (V_T).

The switch automatically turns OFF regardless of the logic controls when an overvoltage is detected. The source pin becomes high impedance and ensures only small leakage current flows through the switch. The drain pin (Dx) is left floating when the fault channel is selected by the logic control. For example, if the source voltage exceeds V_DD or V_SS, then the drain output is left floating and the circuit connected to the drain pin, such as R_L and C_L, determines the final voltage.