Dual SP4T analog multiplexer for commercial signal routing
The Maxim Integrated MAX359CWE+ is a dual SP4T analog multiplexer/demultiplexer in a 16-SOIC package. Each of the two independent circuits selects one of four inputs to a common output, implementing a 4:1 mux function.
1.8 kOhm on-resistance — what it means for signal integrity
The maximum on-state resistance of 1.8 kOhm is high by modern standards. In a voltage-divider configuration with a typical 10 kOhm load, the mux adds roughly 15% attenuation. For precision analog measurements, the load impedance should be at least 100 kOhm to keep the insertion loss below 2%. The resistance also varies with supply voltage and signal level — the datasheet curve should be consulted for the operating point. This part is not suited for low-impedance or high-current paths.
Dual-supply requirement and single-supply compatibility
The MAX359CWE+ is specified for dual supplies only — ±4.5 V to ±18 V. If a single supply is the only option, look for a different mux family. The dual-rail requirement means the analog signal swing can go negative relative to ground, which is useful for bipolar signals in ATE or audio crosspoint matrices.
Switching speed and leakage
Typical turn-on and turn-off times are 300 ns each. This is adequate for audio-frequency multiplexing, relay-replacement, and low-speed data acquisition (sample rates below 1 MHz).
The 16-SOIC wide-body package (0.295-inch body width, 7.50 mm) is a surface-mount footprint common for analog muxes.