Dual SP4T analog switch — what it is and where it fits
The Maxim Integrated MAX4559CEE+ is a dual SP4T (single-pole, four-throw) analog switch, also configurable as a 4:1 multiplexer/demultiplexer per channel. It switches signals up to the supply rails with a maximum on-resistance of 160 ohms and channel-to-channel matching within 2 ohms. The part runs on a single supply from 2V to 12V or dual supplies from ±2V to ±6V, making it suitable for both single-rail and split-rail analog designs. Typical applications include audio signal routing, data acquisition systems, and test equipment where low crosstalk (-93dB at 100kHz) and low charge injection (2.4pC) preserve signal integrity. The commercial temperature range (0°C to 70°C) limits it to indoor, controlled environments — not for automotive or extended industrial use.
160 ohm on-resistance — what it means for your signal path
The 160 ohm maximum on-resistance introduces a voltage divider with the load impedance.
Switching speed and signal fidelity
Turn-on time is 150 ns max, turn-off 120 ns max — fast enough for audio crossfades, relay-replacement, and low-speed data multiplexing up to a few megahertz. The 2.4 pC charge injection produces a small glitch when switching; in sample-and-hold or precision integrator circuits, that glitch can cause a voltage error unless the downstream stage settles. Off-leakage is just 1 nA max, so the switch does not bleed signal into off-channels. Channel capacitance (2.5 pF source off, 6 pF drain off) contributes to settling time — keep source impedance low to avoid RC roll-off in the signal bandwidth.
Package and footprint
The MAX4559CEE+ comes in a 16-pin SSOP package (0.154" body width, 3.90 mm) and is also specified with the supplier device package as 16-QSOP. Both refer to the same compact surface-mount footprint. It ships in a tube — not tape-and-reel — so factor that into your pick-and-place setup if you are running high-volume reflow. The part is ROHS3 compliant, no lead or restricted substances.
Lifecycle and sourcing
That means you can design it into a new BOM without worrying about a last-time-buy window closing. No second-source alternate is listed in the official record, but the part is widely stocked across the independent channel.