Analog Devices Inc. ADG7421F Dual Single-Pole/Single-Throw Switch features overvoltage protection, power-off protection, and overvoltage detection on the source pins. When no power supplies are present, the switch remains in the off condition, and the switch inputs are high impedance. When powered, if the analog input signal levels on the Sx pins exceed VDD or VSS by a threshold voltage, VT, the switch automatically turns off and the digital FF (fault flag) pin drops to a logic low to indicate a fault.