The HI-506/HI-507 and HI-508/HI-509 monolithic CMOS multiplexers each include an array of sixteen and eight analog switches respectively, a digital decoder circuit for channel selection, voltage reference for logic thresholds, and an enable input for device selection when several multiplexers are present. The Dielectric Isolation (DI) process used in fabrication of these devices eliminates the problem of latchup. DI also offers much lower substrate leakage and parasitic capacitance than conventional junction isolated CMOS (see Application Notes AN520 and AN521).