Switch topology and supply flexibility
The MAX4509ESE+ packs two independent SP4T (single-pole, four-throw) switches into a 16-SOIC, giving you a 4:1 multiplexer/demultiplexer per channel. That means you can route one of four analog signals to a common output in each half of the package. That wide compliance means you can drop it into a ±15 V industrial analog front-end or a 24 V single-supply data-acquisition board without a rail converter.
On-resistance and signal integrity
Maximum on-resistance is 400 Ohm, with channel-to-channel matching held to 15 Ohm max. For a precision analog mux driving a high-impedance ADC input, that matching keeps the voltage-divider error consistent across channels — you calibrate it out once in software. Switching is fast: 275 ns turn-on, 200 ns turn-off max. Charge injection is just 2 pC, so the glitch injected into the signal path when switching channels is small enough that a 100 nF cap on the output absorbs it without a visible step on a scope. Off-leakage current is 500 pA max, and the off-channel capacitance is 10 pF per switch, 14 pF per drain. Crosstalk between channels is -62 dB at 1 MHz — that keeps a 1 Vpp, 1 MHz signal on one channel from bleeding more than about 0.8 mV into an adjacent off-channel.