Quad SPST-NC switch for precision signal routing
The Maxim MAX391ESE+ is a quad single-pole single-throw normally-closed (SPST-NC) analog switch in a 16-pin SOIC package. Each of the four independent switches connects a common terminal to a normally-closed pole when the control logic is low. The part is specified for single-supply operation from 3 V to 15 V or dual supplies from ±3 V to ±8 V, covering the common rails for industrial analog front-ends and data-acquisition systems.
Key ratings and what they mean for the BOM
On-resistance of 35 ohms maximum with channel-to-channel matching of 300 milliohms ensures consistent attenuation across all four signal paths — important for gain-stage switching where R_on tolerance shifts the voltage divider ratio. Switching times of 130 ns turn-on and 75 ns turn-off support multiplexing rates into the low-MHz range, adequate for scanning multiple sensor channels in a PLC analog input module or routing audio signals in a mixing console. Crosstalk of -85 dB at 1 MHz is specified. Charge injection of 2 pC and off-leakage of 100 pA maximum suit sample-and-hold circuits and high-impedance sensor interfaces where injected charge or leakage would corrupt the held voltage. Operating temperature from -40°C to 85°C covers industrial environments — motor drives, outdoor telecom cabinets, and factory-floor I/O racks. The 16-SOIC footprint is a standard narrow-body package, compatible with automated assembly lines.
Sourcing and lifecycle
The MAX391ESE+ carries an active lifecycle status and is ROHS3 compliant.