What the MAX391CSE+ is and where it fits
The Maxim MAX391CSE+ is a quad SPST-NC (normally-closed) analog switch in a 16-SOIC package. Each of the four switches passes signals rail-to-rail on a single 3V to 15V supply or a dual ±3V to ±8V supply. The 35 Ohm max on-resistance with 300 mOhm channel-to-channel matching keeps gain errors predictable in precision analog paths. Switching completes in 130 ns turn-on and 75 ns turn-off, fast enough for audio routing, multiplexed data acquisition, or sample-and-hold front ends. Off-leakage stays at 100 pA max, and charge injection is 2 pC typical — both specs matter when the switch feeds a high-impedance ADC input or a long-hold integrator. Not rated for the engine bay or a rooftop enclosure without active cooling.
Crosstalk and isolation — what -85 dB at 1 MHz means
Crosstalk is specified at -85 dB at 1 MHz.
Package and supply — board-fit constraints
The 16-SOIC (0.154" body width, 3.90 mm) is a standard footprint shared by hundreds of analog switches and op-amps. The MAX391CSE+ ships in a Tube — if your pick-and-place line expects Tape & Reel, confirm the packing option at quote time. Supply flexibility is a strong point: a single 3V to 15V rail or split ±3V to ±8V rails. On a 5V-only board, the switch works with no extra regulator. On a ±5V analog supply, it matches the common industrial bipolar rail.
Lifecycle and sourcing posture
The MAX391CSE+ carries an Active lifecycle status and is ROHS3 compliant. No end-of-life notice, no last-time-buy schedule.