The Maxim Integrated MAX309ESE+T is a dual 4:1 analog multiplexer / demultiplexer — two independently selectable SP4T switches in a single 16-SOIC package. Each switch routes one of four analog inputs to a common output, with a break-before-make switching action that prevents momentary shorting between channels. The 100 Ohm max on-resistance is the headline figure: it sets the voltage drop across the switch at a given load current and directly affects the accuracy of sampled analog signals. Typical applications include data-acquisition front-ends, audio routing, test equipment, and industrial sensor multiplexing where multiple analog channels share one ADC or amplifier.
Signal integrity specs that matter
Crosstalk is rated at -92 dB at 100 kHz — that is the isolation between two active channels.