The ADG438F/ADG439F is a high performance 4/8 channel fault-protected analog multiplexer. This multiplexer has fast switching times (tON 250 ns max, tOFF 150 ns max), fault protection and overvoltage protection (-40 V, +55 V), all switches off with power supply off, analog output of ON channel clamped within power supplies if an overvoltage occurs, high reliability structure, TTL and CMOS compatible inputs, etc., which can be applied to data acquisition systems, industrial and process control systems, avionics test equipment, signal routing between systems and high reliability control systems.