The MAX4510/MAX4520 single-pole/single-throw (SPST), fault-protected analog switches feature a fault-protected input and Rail-to-Rail signal-handling capability. The normally open (NO) and normally closed (NC) terminals are protected from overvoltage faults up to 36V during power-on and 44V with power off. During a fault condition, the switch input terminal (NO or NC) becomes an open circuit; only nanoamperes of leakage current flow from the fault source, and the switch output (COM) furnishes up to 13mA of the appropriate polarity supply voltage to the load. This ensures unambiguous rail-to-rail outputs when a fault begins and ends.