Dual 4:1 analog mux with 450 ohm on-resistance
The Maxim DG509ACWE+ is a dual SP4T (single-pole, four-throw) analog multiplexer, also configurable as a demultiplexer, in a 16-SOIC surface-mount package. Each of the two independent switch circuits selects one of four inputs to a common output, giving an 8:2 or 4:2 routing capability depending on wiring. The 450 ohm max on-resistance is the key parametric — it sets the voltage drop across the switch for a given signal current and defines the RC time constant with the load capacitance. For precision analog signals, the 27 ohm channel-to-channel matching keeps gain errors consistent across paths.
Dual supply range and signal swing
Rated for dual supplies from ±4.5 V to ±18 V, the DG509ACWE+ can handle bipolar analog signals up to the supply rails minus the on-resistance drop. The 1.5 µs turn-on and 1 µs turn-off times are adequate for low-speed scanning and relay-replacement applications where microsecond-level settling is acceptable.