Switch topology and parametric fit
The MAX4520EUA+ is a single-pole single-throw normally-open (SPST-NO) analog switch from Analog Devices, configured as a 1:1 multiplexer/demultiplexer. Its 160 Ohm maximum on-resistance is moderate for precision analog signal routing — expect a voltage divider effect when driving low-impedance loads, so budget the Rds(on) drop into the signal chain gain error. Charge injection is specified at 1.5 pC typical. In a sample-and-hold front end, that injected charge translates to a voltage glitch of roughly 1.5 pC / Chold — for a 10 nF hold capacitor, expect a 150 µV step.
Supply rails and signal range
With dual rails, the analog signal swing can approach the supply voltage — useful for ±10 V industrial ADC inputs. The single-supply mode covers 24 V industrial buses directly without a secondary regulator. Leakage current is a maximum 500 pA off-state, and channel capacitance is 10 pF on the source side, 5 pF on the drain side. For a 10 kOhm source impedance, the RC time constant is 100 ns — well below the switch's own switching time, so the bandwidth is set by the external circuit, not the switch.
Housed in an 8-pin uMAX/uSOP package (equivalent to 8-TSSOP/MSOP, 0.118 inch width), the MAX4520EUA+ is surface-mount and supplied in Tube packaging.